Overhauling a Dell Dimension 8400

[Searcher7]

I picked up a Dell Dimension 8400, and when I finally managed to open
the case to take inventory, there was, a 10G IDE hard drive, a CD-RW
drive the slave on the same cable, and a floppy drive.

All were loosely placed in the drive compartments with no way to
secure them. I'm not familiar with these PC cases, and there aren't
any screw holes in the three metal drive compartments, so obviously
I'm missing some parts that were used to hold the drives in place. Can
someone elaborate on what they are?

I want to upgrade the 256mb ram, and add drives anyway, so should I
just ditch the case for another? Or is there a plausible way to secure
drives inside these compartments which lack other hardware?

Thanks.

Darren Harris
Staten Island, New York.

 

[Paul]

I picked up a Dell Dimension 8400, and when I finally managed to open
the case to take inventory, there was, a 10G IDE hard drive, a CD-RW
drive the slave on the same cable, and a floppy drive.

All were loosely placed in the drive compartments with no way to
secure them. I'm not familiar with these PC cases, and there aren't
any screw holes in the three metal drive compartments, so obviously
I'm missing some parts that were used to hold the drives in place. Can
someone elaborate on what they are?

I want to upgrade the 256mb ram, and add drives anyway, so should I
just ditch the case for another? Or is there a plausible way to secure
drives inside these compartments which lack other hardware?

Thanks.

Darren Harris
Staten Island, New York.

I see some slides in the manual. Funny what the owner would
have done with them. The slides generally are different,
on different computer cases, so there is no point keeping them.
Unless maybe, you owned a second 8400.

http://support.dell.com/support/edocs/systems/dim8400/SM/parts.htm#wp1054037

Paul

 

[Ed_]

I picked up a Dell Dimension 8400, and when I finally managed to open
the case to take inventory, there was, a 10G IDE hard drive, a CD-RW
drive the slave on the same cable, and a floppy drive.

All were loosely placed in the drive compartments with no way to
secure them. I'm not familiar with these PC cases, and there aren't
any screw holes in the three metal drive compartments, so obviously
I'm missing some parts that were used to hold the drives in place. Can
someone elaborate on what they are?

I want to upgrade the 256mb ram, and add drives anyway, so should I
just ditch the case for another? Or is there a plausible way to secure
drives inside these compartments which lack other hardware?

Thanks.

Darren Harris
Staten Island, New York.

Go here and download the manual. This will solve most of your problems.

http://support.dell.com/support/edocs/systems/dim8400/

http://support.dell.com/support/edocs/systems/dim8400/SM/parts.htm#wp1054591

Ed_

 

[Ed_]

I see some slides in the manual. Funny what the owner would
have done with them. The slides generally are different,
on different computer cases, so there is no point keeping them.
Unless maybe, you owned a second 8400.

http://support.dell.com/support/edocs/systems/dim8400/SM/parts.htm#wp1054037

Paul

If I remember right, the xtra slides/rails are attached to the inside covers of
the drive bays. It's been a few years since I worked on one but I thought that
it was rather easy and the cable management made everything very accessible.

Anyway, there is excellent documentation for these older Dimensions on the
support page, so the OP should have no problem upgrading this, using the dell
case.

Ed_

 

[Tadpoleuk]

The cdrom, floppy and harddrive should be a connected to the case with green runners that should be screwed to the drives so they slot in and out of the case without the need for tools.

On my mums case there are spare green runners taped to the lid.

If your case is missing the runners and you cant get replacements I personally would just buy a new case.
Easier than trying to make mounting bays for everything you want to put in.


Not just any memory fits these so when you order some I would search for memory compatible with the Dimension 8400 rather than just searching for DDR 400. The slot is in a different place from all of the memory I had hanging round in my PC graveyard.

The case has a button at the top and bottom and opens like a book, So its easier to open it upright and then turn it over to work on it when the hinge is open full.

 

[William R. Walsh]

Hi!

I picked up a Dell Dimension 8400, and when I finally
managed to open the case to take inventory, there was,
a 10G IDE hard drive

Surprising. I know that when I ordered my Dim8300 directly from Dell,
the smallest drive choice available was an 80GB unit. (It was toward
the end of the 8300's lifetime.) All the uplevel drive choices were
SATA.

Something makes me think that someone shoved whatever parts would fit
into the system to "make it work".

I would doubt that the Dim8400 *ever* came with a PATA hard disk from
the factory.

a CD-RW drive the slave on the same cable

Dell didn't do it that way from the factory.

I'm not familiar with these PC cases, and there aren't
any screw holes in the three metal drive compartments,
so obviously I'm missing some parts that were used
to hold the drives in place. Can someone elaborate on
what they are?

Dell used a series of green rails to mount the drives in this system.
You may have spares stuck to the inside of the case, on the half that
opens up. If you do, use those. If not, someone here probably has
some. I have some that I don't need on a loose hard drive, so if all
else fails...pay postage and they're yours.

(You can contact me off group using wct <atsign> walshcomptech <dot>
com...)

These rails plug or screw into the screw holes in each drive, and then
you slide the drive into the case.

I want to upgrade the 256mb ram, and add drives
anyway, so should I just ditch the case for another?

I'm not sure you can do that, the motherboard may not quite fit.

The Dim8400 is a pretty competent machine, with the Intel 915 chipset
and an LGA775 Pentium 4 CPU. I think it would be worthwhile to put a
few dollars worth of work into it...it still performs quite well.

William

 

[Ben Myers]

Hi!


Surprising. I know that when I ordered my Dim8300 directly from Dell,
the smallest drive choice available was an 80GB unit. (It was toward
the end of the 8300's lifetime.) All the uplevel drive choices were
SATA.

Something makes me think that someone shoved whatever parts would fit
into the system to "make it work".

I would doubt that the Dim8400 *ever* came with a PATA hard disk from
the factory.


Dell didn't do it that way from the factory.


Dell used a series of green rails to mount the drives in this system.
You may have spares stuck to the inside of the case, on the half that
opens up. If you do, use those. If not, someone here probably has
some. I have some that I don't need on a loose hard drive, so if all
else fails...pay postage and they're yours.

(You can contact me off group using wct <atsign> walshcomptech <dot>
com...)

These rails plug or screw into the screw holes in each drive, and then
you slide the drive into the case.


I'm not sure you can do that, the motherboard may not quite fit.

The Dim8400 is a pretty competent machine, with the Intel 915 chipset
and an LGA775 Pentium 4 CPU. I think it would be worthwhile to put a
few dollars worth of work into it...it still performs quite well.

William

Correction. The Dimension 8400 motherboard, mounted on a metal plate,
will NOT fir in a generic computer case without substantial surgery to
either the motherboard or the case. People are warned not to try this
at home. I don't ever do it either at the office... Ben Myers

 

[Ben Myers]

I have a Dell 2400 that was done "That Way".

The Dimension 2400 (also 2300, 2350, 4600, 4700, B110, 3000 and Optiplex
GX170) chassis is a microATX chassis in which Dell could have cabled the
hard drive and the optical drive together on one IDE cable.

Distances between drive bays on the Dimension 8400 (also 8300, 8200,
8250, 4550, 4500, 4400, 4300 and various Precision models) are such that
it is nearly impossible to cable optical drive and hard drive together
if they are mounted as Dell did at the factory. To do so would also
require a non-standard cable longer than the 18" standard, and likely to
cause sporadic malfunctions of drives due to corrupted electronic
signals carried along the too-long cable... Ben Myers

 

[Searcher7]

Hi!


Surprising. I know that when I ordered my Dim8300 directly from Dell,
the smallest drive choice available was an 80GB unit. (It was toward
the end of the 8300's lifetime.) All the uplevel drive choices were
SATA.

Something makes me think that someone shoved whatever parts would fit
into the system to "make it work".

I would doubt that the Dim8400 *ever* came with a PATA hard disk from
the factory.


Dell didn't do it that way from the factory.


Dell used a series of green rails to mount the drives in this system.
You may have spares stuck to the inside of the case, on the half that
opens up. If you do, use those. If not, someone here probably has
some. I have some that I don't need on a loose hard drive, so if all
else fails...pay postage and they're yours.

(You can contact me off group using wct <atsign> walshcomptech <dot>
com...)

These rails plug or screw into the screw holes in each drive, and then
you slide the drive into the case.


I'm not sure you can do that, the motherboard may not quite fit.

The Dim8400 is a pretty competent machine, with the Intel 915 chipset
and an LGA775 Pentium 4 CPU. I think it would be worthwhile to put a
few dollars worth of work into it...it still performs quite well.

William

Thanks.

Your e-mail bounced back.

Darren Harris
Staten Island, New York.

 

[William R. Walsh]

Hi!

Your e-mail bounced back.

You can't just reply to.

http://www.walshcomptech.com/contact.htm

William

 

[Searcher7]

Ok. I'm back to trying to get this pc working thanks to one option after another failing me. (I didn't know I could post to Google thread that is overfour years old).

Thanks to one pc option after nother failing one way or the other I'm back to trying to get this DELL 8400 up and working.

I just replaced the CMOS battery. I connected a SATA hard drive to SATA 0 and a SATA DVD drive to SATA 1. (I have 2G of ram installed: http://www.ec.kingston.com/ecom/configurator_new/PartsInfo.asp?ktcpartno=KVR667D2N5/1G

When I power on the hard drive spins up and the DVD light turns on, but thepc will not send a signal to the monitor. And the four diagnostic lights at the rear of the case do not come on at all. I tried powering up with justa single IDE hard drive also. (So it would seem that this is a pre-BIOS failure occurring).

Before this goes into the trash I have to find out if the problem is the video card or the motherboard.

Is the fan supposed to be located *inside* the airflow shroud? I noticed that now this pc does not have an airflow shroud in place. (When it was partly working over fours years ago I was getting a fan failure message).

The video card is a Diamond Stealth 3D 2000 that is plugged into a PCI slot, and not one of the 1/2 dozen video cards I have are PCI. (The motherboardalso has an empty PCI Express x16 slot and PCI Express x1 slot). Now sinceI'd hate to have to buy a new PCI video card for nothing I thought I'd askif there might be something I'm missing or something I should do before I go that route.

(I've been using the following:
http://support.dell.com/support/edocs/systems/dim8400/SM/parts.htm#wp1054591
http://www.dell.com/support/Manuals/us/en/19/Product/dimension-8400

Thanks.

Darren Harris
Staten Island, New York.

 

[Paul]

Ok. I'm back to trying to get this pc working thanks to one option after another failing me. (I didn't know I could post to Google thread that is over four years old).

Thanks to one pc option after nother failing one way or the other I'm back to trying to get this DELL 8400 up and working.

I just replaced the CMOS battery. I connected a SATA hard drive to SATA 0 and a SATA DVD drive to SATA 1. (I have 2G of ram installed: http://www.ec.kingston.com/ecom/configurator_new/PartsInfo.asp?ktcpartno=KVR667D2N5/1G

When I power on the hard drive spins up and the DVD light turns on, but the pc will not send a signal to the monitor. And the four diagnostic lights at the rear of the case do not come on at all. I tried powering up with just a single IDE hard drive also. (So it would seem that this is a pre-BIOS failure occurring).

Before this goes into the trash I have to find out if the problem is the video card or the motherboard.

Is the fan supposed to be located *inside* the airflow shroud? I noticed that now this pc does not have an airflow shroud in place. (When it was partly working over fours years ago I was getting a fan failure message).

The video card is a Diamond Stealth 3D 2000 that is plugged into a PCI slot, and not one of the 1/2 dozen video cards I have are PCI. (The motherboard also has an empty PCI Express x16 slot and PCI Express x1 slot). Now since I'd hate to have to buy a new PCI video card for nothing I thought I'd ask if there might be something I'm missing or something I should do before I go that route.

(I've been using the following:
http://support.dell.com/support/edocs/systems/dim8400/SM/parts.htm#wp1054591
http://www.dell.com/support/Manuals/us/en/19/Product/dimension-8400

Thanks.

Darren Harris
Staten Island, New York.

Sometimes, you have to rely on archive.org to see the old pages.
The air shroud one is here.

http://web.archive.org/web/20050114.../edocs/systems/dim8400/sm/parts.htm#wp1057570

I can see some examples here, showing the shroud and fan. The fan
appears to have a 1x4 inline connector. Make sure the fan is connected,
and connected properly. (With connectors, unless they have a key,
they can get rotated on you. Make absolutely sure which way round,
as otherwise, you could ruin a part by connecting the power backwards
to it.)

http://s300083406.websitehome.co.uk/ep/hp/t4307-3.jpg

http://s300083406.websitehome.co.uk/ep/hp/t4307-4.jpg

Since the BIOS is not responding, things I'd try:

1) Remove excess cards. Use the "simplify" method of testing,
removing as much hardware as possible to make it easier to
understand the test results.

2) Operate with motherboard, CPU, CPU cooling fan connected.
Disconnect drives. Remove video card. Remove RAM and store in an
antistatic bag.

The four light diagnostic should be able to light up, showing
"video error" or "RAM error", in cases where the RAM is removed as well.

3) Leave the PC case speaker connected, so the BIOS can beep an error code.

Now, verify the CPU is seated. Cooler is in place. CPU fan is plugged in.

Make sure the power connectors are all in place. Especially
the ATX12V 2x2 with the two yellow wires (+12V) and the
two black wires (ground).

This is what an ATX12V 2x2 looks like. Square connector, with latching tab.
It should only fit one way, with latching tab meeting latching tab.

http://www.playtool.com/pages/psuconnectors/12v4pin.jpg

( http://www.playtool.com/pages/psuconnectors/connectors.html )

Lastly, do a visual inspection of the capacitors. (The aluminum cylinders
with colored plastic sleeves to insulate them.) Bulging or leaking caps,
can cause the computer to fail to POST, and the BIOS won't be running
if an internal regulator on the motherboard has failed. If the caps
are allowed to fail completely, the overload can blow MOSFETs and
burn toroids, making repair much more difficult than just buying
a "recapping kit". You want to catch bad caps, before they ruin the
computer, and cause other parts to burn.

Paul

 

[Searcher7]

Sometimes, you have to rely on archive.org to see the old pages.
The air shroud one is here.

http://web.archive.org/web/20050114031417/http://support.dell.com/sup...

I can see some examples here, showing the shroud and fan. The fan
appears to have a 1x4 inline connector. Make sure the fan is connected,
and connected properly. (With connectors, unless they have a key,
they can get rotated on you. Make absolutely sure which way round,
as otherwise, you could ruin a part by connecting the power backwards
to it.)

http://s300083406.websitehome.co.uk/ep/hp/t4307-3.jpg

http://s300083406.websitehome.co.uk/ep/hp/t4307-4.jpg

Since the BIOS is not responding, things I'd try:

1) Remove excess cards. Use the "simplify" method of testing,
    removing as much hardware as possible to make it easier to
    understand the test results.

2) Operate with motherboard, CPU, CPU cooling fan connected.
    Disconnect drives. Remove video card. Remove RAM and store in an
    antistatic bag.

    The four light diagnostic should be able to light up, showing
    "video error" or "RAM error", in cases where the RAM is removed as well.

3) Leave the PC case speaker connected, so the BIOS can beep an error code.

Now, verify the CPU is seated. Cooler is in place. CPU fan is plugged in.

Make sure the power connectors are all in place. Especially
the ATX12V 2x2 with the two yellow wires (+12V) and the
two black wires (ground).

This is what an ATX12V 2x2 looks like. Square connector, with latching tab.
It should only fit one way, with latching tab meeting latching tab.

http://www.playtool.com/pages/psuconnectors/12v4pin.jpg

    (http://www.playtool.com/pages/psuconnectors/connectors.html)

Lastly, do a visual inspection of the capacitors. (The aluminum cylinders
with colored plastic sleeves to insulate them.) Bulging or leaking caps,
can cause the computer to fail to POST, and the BIOS won't be running
if an internal regulator on the motherboard has failed. If the caps
are allowed to fail completely, the overload can blow MOSFETs and
burn toroids, making repair much more difficult than just buying
a "recapping kit". You want to catch bad caps, before they ruin the
computer, and cause other parts to burn.

    Paul- Hide quoted text -

- Show quoted text -

Well, like I mentioned I do not have the airflow shroud, so there is
no fan there.

Unfortunately, I ran into another problem.

I attempted to turn the machine on and nothing at all happened. I
changed nothing between the last time I had it on so this is a
mystery. (I don't know if it could be the problem, but when I last had
it on I plugged in the power cord *before* I plugged a hard drive into
the IDE cable. When the hard drive spun up immediately I realized that
the machine was on). ?!?

I turned it off last night and today the green light on the
motherboard lights up when the power cord is in the outlet, but that
is all.

As for what you said to do, I will remove the drive, video card, and
ram to log what happens, but that is all I can see doing now. The pc
speaker I think is a little black cylinder on the motherboard. I've
not heard a peep out of it yet, but we'll see what happens tonight.

I know everything else is connected correctly and I already checked
all the caps.

Thanks.

Darren Harris
Staten Island, New York.

 

[Paul]

Well, like I mentioned I do not have the airflow shroud, so there is
no fan there.

Unfortunately, I ran into another problem.

I attempted to turn the machine on and nothing at all happened. I
changed nothing between the last time I had it on so this is a
mystery. (I don't know if it could be the problem, but when I last had
it on I plugged in the power cord *before* I plugged a hard drive into
the IDE cable. When the hard drive spun up immediately I realized that
the machine was on). ?!?

I turned it off last night and today the green light on the
motherboard lights up when the power cord is in the outlet, but that
is all.

As for what you said to do, I will remove the drive, video card, and
ram to log what happens, but that is all I can see doing now. The pc
speaker I think is a little black cylinder on the motherboard. I've
not heard a peep out of it yet, but we'll see what happens tonight.

I know everything else is connected correctly and I already checked
all the caps.

Thanks.

Darren Harris
Staten Island, New York.

So you're saying you get the green LED (presence of +5VSB from power supply),
but nothing else. The power supply has two halves, one half provides +5VSB
before the fans start running. The second half, provides +3.3V, 5V, 12V
to run the system normally.

That means:

1) Front panel power button disconnected. Front panel power button broken.
2) Logic failure in Southbridge or SuperI/O chip, affecting
ability to convert front power button pulse, into PS_ON#
signal to the power supply.
3) Main portion of power supply has failed, and is ignoring
the PS_ON# signal.
4) On some Dells, if the Northbridge heatsink falls off (the
spring clip used to pull out on some of those), that shuts off
the power. The idiots knew the clip could pull out, so they
put in a safety feature to detect it. Now, if they'd only
been so clever, as to avoid the thing pulling out on its own
in the first place. All it would have taken, is proper soldering
techniques. Someone knew what they were doing was wrong, and
that's why they added a safety feature. And the symptoms are,
the power won't come on.

As for your mention of a previous symptom, if the power
comes on immediately, the instant you plug in the power cable,
that means the Southbridge is under electrical stress. I had
a computer where that happened, and a half-plugged-in IDE cable
did it. As soon as the back power switch was engaged, it
tried to boot. Scared the crap out of me. A careful visual
review of the inside of my PC, revealed I'd bumped the IDE
cable, the last time I was in there. Fortunately, no
permanent damage was done by my error. Once the IDE cable
was fully seated (with the power off of course), I was
ready to use the PC in a normal way.

HTH,
Paul

 

[Searcher7]

So you're saying you get the green LED (presence of +5VSB from power supply),

but nothing else. The power supply has two halves, one half provides +5VSB

before the fans start running. The second half, provides +3.3V, 5V, 12V

to run the system normally.



That means:



1) Front panel power button disconnected. Front panel power button broken..

2) Logic failure in Southbridge or SuperI/O chip, affecting

ability to convert front power button pulse, into PS_ON#

signal to the power supply.

3) Main portion of power supply has failed, and is ignoring

the PS_ON# signal.

4) On some Dells, if the Northbridge heatsink falls off (the

spring clip used to pull out on some of those), that shuts off

the power. The idiots knew the clip could pull out, so they

put in a safety feature to detect it. Now, if they'd only

been so clever, as to avoid the thing pulling out on its own

in the first place. All it would have taken, is proper soldering

techniques. Someone knew what they were doing was wrong, and

that's why they added a safety feature. And the symptoms are,

the power won't come on.



As for your mention of a previous symptom, if the power

comes on immediately, the instant you plug in the power cable,

that means the Southbridge is under electrical stress. I had

a computer where that happened, and a half-plugged-in IDE cable

did it. As soon as the back power switch was engaged, it

tried to boot. Scared the crap out of me. A careful visual

review of the inside of my PC, revealed I'd bumped the IDE

cable, the last time I was in there. Fortunately, no

permanent damage was done by my error. Once the IDE cable

was fully seated (with the power off of course), I was

ready to use the PC in a normal way.



HTH,

Paul

Ok, I assumed that if the problem wasn't the motherboard, then it was either the power supply or F-Panel connection. Not one of my 10 power supplies have 24 position cables like this DELL, and the f-panel cable is different than any pc I've ever had, but on a whim I changed the "Clear CMOS" jumper to pins 1 & 2 and the pc came on. (But it wouldn't shut off). ?!? So I put the jumper back to pins 2 & 3 and hit the power switch, which is finally working.

However, the diagnostic lights at the rear of the case still do nothing at all.

Unless, finding an airflow shroud with fan will make a difference in the initial symptoms I can't think of anything left to do.

Darren Harris
Staten Island, New York.

 

[Paul]

Ok, I assumed that if the problem wasn't the motherboard, then it was either the power supply or F-Panel connection. Not one of my 10 power supplies have 24 position cables like this DELL, and the f-panel cable is different than any pc I've ever had, but on a whim I changed the "Clear CMOS" jumper to pins 1 & 2 and the pc came on. (But it wouldn't shut off). ?!? So I put the jumper back to pins 2 & 3 and hit the power switch, which is finally working.

However, the diagnostic lights at the rear of the case still do nothing at all.

Unless, finding an airflow shroud with fan will make a difference in the initial symptoms I can't think of anything left to do.

Darren Harris
Staten Island, New York.

Do you know if the diagnostic lights connect to the motherboard
via some kind of ribbon cable ?

Perhaps some cabling isn't plugged in.

You can use 20 pin power supplies with a 24 pin motherboard.
The extra four pins are redundant. The only situation you have
to watch for, is when the add-in cards in your computer, draw
a lot of +12V. An example would be a 24 pin motherboard,
two video slots, two 6600 video cards drawing 4 amps from 12V
each. That would be 8 amps current flow, and too much for the
single yellow wire on the 20 pin connector. If you have only
one video card, then it's generally safe to use a 20 pin supply.
And even high power cards, tend to draw less current from the
slot. A high end card might draw 12V @ 2A, in which case
two high end video cards wouldn't over-burden the connector.
It's only the mid-range cards which draw 4A from the slot, and
using two cards would be a problem.

This is what plugging a 20 pin, into a 24 pin motherboard
would look like. Pin 1 goes to Pin 1. The shaping of the
pins, guides correct alignment. The PSU latch might not
click into the motherboard connector (but it's better if
the latch does engage). The PSU latch is there to prevent
the connector from working itself loose via thermal expansion.

http://www.playtool.com/pages/psuconnectors/20in24.jpg

( http://www.playtool.com/pages/psuconnectors/connectors.html )

If you read that page, you'll also note that Dell went through
an era of using proprietary wiring for the main power supply
connector. (Dell eventually stopped doing that. At one time,
you'd go to the PC Power And Cooling site, to find a replacement
PSU with the required screwy wiring.) But I don't think that
would be an issue here, as I think that involved 20 pin motherboards.
The Dell 24 pin motherboards should have a conventional pinout,
and also allow using a 20 pin supply.

Paul

 

[Searcher7]

Do you know if the diagnostic lights connect to the motherboard

via some kind of ribbon cable ?



Perhaps some cabling isn't plugged in.



You can use 20 pin power supplies with a 24 pin motherboard.

The extra four pins are redundant. The only situation you have

to watch for, is when the add-in cards in your computer, draw

a lot of +12V. An example would be a 24 pin motherboard,

two video slots, two 6600 video cards drawing 4 amps from 12V

each. That would be 8 amps current flow, and too much for the

single yellow wire on the 20 pin connector. If you have only

one video card, then it's generally safe to use a 20 pin supply.

And even high power cards, tend to draw less current from the

slot. A high end card might draw 12V @ 2A, in which case

two high end video cards wouldn't over-burden the connector.

It's only the mid-range cards which draw 4A from the slot, and

using two cards would be a problem.



This is what plugging a 20 pin, into a 24 pin motherboard

would look like. Pin 1 goes to Pin 1. The shaping of the

pins, guides correct alignment. The PSU latch might not

click into the motherboard connector (but it's better if

the latch does engage). The PSU latch is there to prevent

the connector from working itself loose via thermal expansion.



http://www.playtool.com/pages/psuconnectors/20in24.jpg



( http://www.playtool.com/pages/psuconnectors/connectors.html )



If you read that page, you'll also note that Dell went through

an era of using proprietary wiring for the main power supply

connector. (Dell eventually stopped doing that. At one time,

you'd go to the PC Power And Cooling site, to find a replacement

PSU with the required screwy wiring.) But I don't think that

would be an issue here, as I think that involved 20 pin motherboards.

The Dell 24 pin motherboards should have a conventional pinout,

and also allow using a 20 pin supply.



Paul

I was wondering about that, but didn't want to take the chance because I can't find the DELL pin-outs and the wire colors are not all the same at the respective positions.

I'm actually hoping the problem is the power supply, because after leaving the machine on for 10 minutes I felt no heat whatsoever coming from the processor/heatsink.

Thanks.

Darren Harris
Staten Island, New York.

 

[Searcher7]

Ok, the problem is not the power supply, because the symptoms remain the same wvenwith a new power supply connected.

I guess there is nothing more I can do.

Darren Harris
Staten Island, New York.

 

[Paul]

Ok, the problem is not the power supply, because the symptoms remain the same
even with a new power supply connected.

I guess there is nothing more I can do.

Darren Harris
Staten Island, New York.

All I can suggest is:

1) Simplify hardware setup. Remove extraneous hardware not
necessary to a BIOS level test.

2) Motherboard, CPU, CPU cooler/fan plugged in,
CPU power cable plugged in. Main power plugged in.
Computer case speaker connected. No RAM or video card.
Start system. Look for diagnostic code on four LEDs, or
listen for error beep pattern on computer case speaker.
No reaction, means it's seriously busted.

Reasons for failure:

1) No +12V to processor - plug in the square connector.
2) Some power signal from the power supply is bad. You've
checked that.
3) BIOS chip got corrupted. You can buy another chip from
badflash.com and replace the BIOS chip. I would assign this
a relatively low priority. While EEPROM chips do occasionally
get "bit rot" and the contents can have a few bytes corrupted,
it's not that usual. If the computer was near a source of
ionizing radiation, that could do it.
4) A bad CMOS battery, can prevent a computer from responding
to the power switch. But it shouldn't prevent the BIOS
from being read.
5) A broken Northbridge clip, can deny power to the computer.
The fans won't spin and the PSU won't come on, on certain
Dell computers, if the Northbridge cooler falls off.
6) On motherboards with ICH4 or ICH5, it's possible to have
a latchup failure of the Southbridge. The failures vary in
severity. If you see a chip, with a burn mark like this, then
your motherboard is ruined. Static electricity, is partially
to blame for this. While the docs claim ICH4 can be affected,
the ICH5 is much worse (maybe 30x as many failures).

http://i.onfinite.com/TFG42bkgd.jpg

7) A motherboard is very complicated, as electronic devices go.
There could be at least 1000 copper tracks. Any one of those
tracks, if it cracks, can lead to a failure to boot.

You know, the fact your Dell 4-LED diagnostic is not lighting
up, that still bothers me. Did you check the cabling to that
thing ? Is it lighting up now at all, with a code ?

If your diagnostic code was lighting up, I'd suggest borrowing
a PCI Port 80 card from a local computer shop, and plugging that
into PCI slot #1 and see what codes show on it. The last code value,
is the last BIOS routine to have run before the thing crashed.
In cases where no BIOS code is able to run at all, the PCI port 80
POST test card will display 0xFF or 0x00 on the two digit display.
And then you know it's busted pretty bad, if you're getting 0x00 or
0xFF. Since your Dell 4-LED diagnostic is not lighting up, that's
roughly the same thing as the Port 80 card.

(ISA and PCI versions of a Port 80 diagnostic card... Anywhere from
$25 to $100, depending on whether it comes straight from Hong Kong
or not. The $100 price, is from your local computer store if purchased
as a new item.)

http://img.tomshardware.com/us/2001/07/25/bios_tuning/port80.jpg

Paul

 

[Searcher7]

(e-mail address removed)2.com wrote:








All I can suggest is:



1) Simplify hardware setup. Remove extraneous hardware not

necessary to a BIOS level test.



2) Motherboard, CPU, CPU cooler/fan plugged in,

CPU power cable plugged in. Main power plugged in.

Computer case speaker connected. No RAM or video card.

Start system. Look for diagnostic code on four LEDs, or

listen for error beep pattern on computer case speaker.

No reaction, means it's seriously busted.



Reasons for failure:



1) No +12V to processor - plug in the square connector.

2) Some power signal from the power supply is bad. You've

checked that.

3) BIOS chip got corrupted. You can buy another chip from

badflash.com and replace the BIOS chip. I would assign this

a relatively low priority. While EEPROM chips do occasionally

get "bit rot" and the contents can have a few bytes corrupted,

it's not that usual. If the computer was near a source of

ionizing radiation, that could do it.

4) A bad CMOS battery, can prevent a computer from responding

to the power switch. But it shouldn't prevent the BIOS

from being read.

5) A broken Northbridge clip, can deny power to the computer.

The fans won't spin and the PSU won't come on, on certain

Dell computers, if the Northbridge cooler falls off.

6) On motherboards with ICH4 or ICH5, it's possible to have

a latchup failure of the Southbridge. The failures vary in

severity. If you see a chip, with a burn mark like this, then

your motherboard is ruined. Static electricity, is partially

to blame for this. While the docs claim ICH4 can be affected,

the ICH5 is much worse (maybe 30x as many failures).



http://i.onfinite.com/TFG42bkgd.jpg



7) A motherboard is very complicated, as electronic devices go.

There could be at least 1000 copper tracks. Any one of those

tracks, if it cracks, can lead to a failure to boot.



You know, the fact your Dell 4-LED diagnostic is not lighting

up, that still bothers me. Did you check the cabling to that

thing ? Is it lighting up now at all, with a code ?



If your diagnostic code was lighting up, I'd suggest borrowing

a PCI Port 80 card from a local computer shop, and plugging that

into PCI slot #1 and see what codes show on it. The last code value,

is the last BIOS routine to have run before the thing crashed.

In cases where no BIOS code is able to run at all, the PCI port 80

POST test card will display 0xFF or 0x00 on the two digit display.

And then you know it's busted pretty bad, if you're getting 0x00 or

0xFF. Since your Dell 4-LED diagnostic is not lighting up, that's

roughly the same thing as the Port 80 card.



(ISA and PCI versions of a Port 80 diagnostic card... Anywhere from

$25 to $100, depending on whether it comes straight from Hong Kong

or not. The $100 price, is from your local computer store if purchased

as a new item.)



http://img.tomshardware.com/us/2001/07/25/bios_tuning/port80.jpg



Paul

I had already followed the steps you listed. With no ram installed. No drives connected. And no cards in any slot, the only thing attached to the motherboard were the main power cable and the CPU(+12V) cable.

There are no diagnostic lights and no beeps. (There is no cabling involved with the diagnostic lights. It's basically a hard plastic case/connector attached to the mother board).

There are no bulging capacitors and I the board has a brand nwe CMOS battery.

There is only that little tiny green light near the main power cable connector that stays on if the power supply is plugged into an outlet, but when Ipower on nothing else outside of the power supply fan coming on happens. (And I also tried a brand new power supply).

So the only question left is if not having a CPU fan plugged into the motherboard a possible reason for this. (I assume this is the one: http://www.ebay.com/itm/261056206863).

Thanks.

Darren Harris
Staten Island,New York.