No video output whatsoever.

  • Thread starter Thread starter Austin H Christ
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A

Austin H Christ

My friend took out his motherboard to see if it would fit in a ne
case, but when he got it in, there was no video output after turnin
on the computer. I've had a decent ammount of experience fixin
computers, so I tried the basic things, flashing the BIOS, trying ne
video cards and monitors and such, and all of the components work
unless they're in that specific computer. There is something tha
makes me think that the motherboard is not broken, and that is tha
when the monitor is powered on and unplugged it says "N
input" and when I plug it in to the video card that message goe
away, but the monitor stays in stand by mode (with the power LE
blinking orange instead of the powered on steady green). I've neve
seen this problem, so if anyone has experienced something similar,
would like to see if it is fixable short of replacing th
motherboard. Thank you
 
what video card?
and if it is pcix did it require a separate power connector and did the new
case/PSU provide it?
 
My friend took out his motherboard to see if it would fit in a new
case, but when he got it in, there was no video output after turning
on the computer. I've had a decent ammount of experience fixing
computers, so I tried the basic things, flashing the BIOS, trying new
video cards and monitors and such, and all of the components work,
unless they're in that specific computer. There is something that
makes me think that the motherboard is not broken, and that is that
when the monitor is powered on and unplugged it says "No
input" and when I plug it in to the video card that message goes
away, but the monitor stays in stand by mode (with the power LED
blinking orange instead of the powered on steady green). I've never
seen this problem, so if anyone has experienced something similar, I
would like to see if it is fixable short of replacing the
motherboard. Thank you.
Click to expand...

Is there a new power supply in this picture ? Are you using a
new ATX 2.0+ power supply that does not have a -5V supply
on the ATX connector. Maybe the motherboard you are using,
had a dependence on -5V for some reason. Try your old power
supply.

If the motherboard has that 2x2 ATX12V connector on it, that
has to be connected for the CPU to pass power on self test.

Paul
 
I am actually attempting to put the same motherboard back in it'
original Hewlett Packard case, so the power supply and everything ar
all what was in it before. I changed the video card from a Radeon 980
Pro to a 9600, and the 9600 does not have the power connection. I wil
try putting the original video card back in, I didn't try that yet
I'm having a minor issue about where the frontal port connections g
on the motherboard, because he took it out and I didn't see wher
they were originally to put them back, but I'm pretty sure I hav
them placed correctly. Even if I didn't would that cause a failure t
POST
 
[email protected] said:
I am actually attempting to put the same motherboard back in it's
original Hewlett Packard case, so the power supply and everything are
all what was in it before. I changed the video card from a Radeon 9800
Pro to a 9600, and the 9600 does not have the power connection. I will
try putting the original video card back in, I didn't try that yet.
I'm having a minor issue about where the frontal port connections go
on the motherboard, because he took it out and I didn't see where
they were originally to put them back, but I'm pretty sure I have
them placed correctly. Even if I didn't would that cause a failure to
POST?
Click to expand...

I guess the first thing that would concern me, is whether the
HP power supply is a standard ATX supply. I don't know if they
use a non-standard wiring pattern or not.

There are a couple specs for ATX supplies. The ones you see now
for sale, are ATX 2.0+, and have a 24 pin connector for the main
power. The previous version had 20 pins, and I'm guessing that
is what is in the HP box. This specification is from before
the 2.0 series of specs. PDF page 30, section 4.5.1 has a
diagram of the pinout, and the wire colors on standard ATX
supplies will generally adhere to the info in the table. (The
3.3V pin has two wires stuffed in it, and the thinner wire is
for remote sensing that the correct 3.3V is there.)

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

There have been some prebuilt machines in the past, where mixing
after market components with the prebuilt machine, results
in stuff getting fried. And that means, when reaching inside of
one of those boxes, you have to ask a few more questions and
take a few more measurements. It is pretty hard to keep track
of all the tricks with these things.

In terms of the PANEL header on a motherboard, the only thing
you need to connect, is the POWER switch from the front panel.
When bench testing, you don't even need that, and I turn on
motherboards here by sliding the tip of a screwdriver between
the PWR and GND pins where the power switch is normally connected.
All it takes is a momentary contact on PWR/GND to start them.
You do need enough documentation to identify those pins, and if
you go to www.hp.com, you can search based on the model number of
the HP machine. In some cases, they give a decent amount of info,
and more than I would be likely to find on the Dell site.

The only HP that disappointed so far, was a "home entertainment
center" box, where they didn't give any info on what is inside,
and treated it as if it was a laptop. But for their other tower
style ATX computers, they are reasonably generous with info.

Paul
 
I am quite frustrated, because both of the computers that had th
motherboards removed are showing the same symptoms and I can't figur
out why. It seems like if the computer failed to POST it would beep
I've had that happen before, but it doesn't. All the fans and light
power up except the video doesn't display, if a motherboard was frie
would everything else still work, and only the video componants b
damaged?

The Emachines he attempted to put his P4 motherboard into originall
had an Athlon with an onboard videocard, and it has the same issue
everything starts up except the monitor just goes into stand by mode
I just don't understand how something could cause these two computer
to do the same exact thing
 
Austin H Christ said:
I am quite frustrated, because both of the computers that had the
motherboards removed are showing the same symptoms and I can't figure
out why. It seems like if the computer failed to POST it would beep,
I've had that happen before, but it doesn't. All the fans and lights
power up except the video doesn't display, if a motherboard was fried
would everything else still work, and only the video componants be
damaged?
Click to expand...

Yes, it is possible to kill more than one motherboard
with a bad or incompat video card.
 
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