Boot freezes, blank display

[juhani.jaakola]

I have a PC with ASRock 939S56-M motherboard and ATI Radeon graphics
card. I have used the system for 14 months. About 2..3 times a month
the system freezes so that I have to cycle power off-on. I do not know
whether those hangs were caused by hardware or software.

Now the system doesn't boot any more. When I turn power on, the CD-ROM
drive and hard disk LEDs blink for a while, and finally the the floppy
disk LED turns on and the system stays like that forever! There are no
beeps from BIOS POST (Power On Self Test). The screen is completely
blank - no memory check messages nor anything else, just a black
screen! I have tried two monitors (one with DVI connection and another
with standard VGA connection), and both monitors remain black!

If I try to boot from a floppy disk or a CD, somethings seems to happen
according to the floppy disk and CD LEDs and sounds, but the monitor is
still totally black!

I have opened the PC and all fans (power supply, processor and graphics
card) work. The cables seem to be OK, but I have not tried to
disconnect and re-connect them.

I have not modified the hardware setup for 14 months.

Any ideas what should I do next?

 

[Joel]

I have a PC with ASRock 939S56-M motherboard and ATI Radeon graphics
card. I have used the system for 14 months. About 2..3 times a month
the system freezes so that I have to cycle power off-on. I do not know
whether those hangs were caused by hardware or software.

Now the system doesn't boot any more. When I turn power on, the CD-ROM
drive and hard disk LEDs blink for a while, and finally the the floppy
disk LED turns on and the system stays like that forever! There are no
beeps from BIOS POST (Power On Self Test). The screen is completely

It seems like the system is booting and probably (I mean Windows) running
in the dark

blank - no memory check messages nor anything else, just a black
screen! I have tried two monitors (one with DVI connection and another
with standard VGA connection), and both monitors remain black!

I am waiting to hear you say you also try different Video Card <g>.
Anyway, try this

1. Remove and re-insert the video card see if it help (may not but won't
hurt to try)

2. If monitor still blank and you don't think anything wrong with the
monitor (how about the cable?) then it's possible that the Video Card is the
one causing the problem.

If I try to boot from a floppy disk or a CD, somethings seems to happen
according to the floppy disk and CD LEDs and sounds, but the monitor is
still totally black!

I have opened the PC and all fans (power supply, processor and graphics
card) work. The cables seem to be OK, but I have not tried to
disconnect and re-connect them.

I have not modified the hardware setup for 14 months.

Any ideas what should I do next?

Try different Video Card I guess.

 

[Rod Speed]

(e-mail address removed) wrote

It seems like the system is booting and probably
(I mean Windows) running in the dark

Not if the floppy led stays on all the time.

I am waiting to hear you say you also try different Video Card <g>.
Anyway, try this

1. Remove and re-insert the video card see if it help (may not but
won't hurt to try)

Try with no video card at all and see if it will beep if replugging it doesnt help.

2. If monitor still blank and you don't think anything
wrong with the monitor (how about the cable?)

He appears to have tried two different cables
with the DVI and VGA both being tried.

then it's possible that the Video Card is the one causing the problem.

Or the motherboard has gone bad. Check for bad caps,
particularly if it wont beep with no video card.

Could be a bad power supply too.

 

[Joel]

Not if the floppy led stays on all the time.

Could be! I haven't had floppy drive installed for over a decade to have
much memory of it.

Try with no video card at all and see if it will beep if replugging it doesnt help.


He appears to have tried two different cables
with the DVI and VGA both being tried.

Got it!

Or the motherboard has gone bad. Check for bad caps,
particularly if it wont beep with no video card.

Could be a bad power supply too.

Could be! but I read he says everything seems kicking ok except the
monitor so I guess the power supply is still ok (never had voltage problem
so don't have much experience with this except losing power in seconds).

 

[Rod Speed]

Could be!

On the other hand he appears to say the opposite
below when booting from a floppy or CD.

I haven't had floppy drive installed for over a decade to have much memory of it.

Got it!

Could be! but I read he says everything seems kicking ok except the
monitor so I guess the power supply is still ok

You could get his symptoms if the power supply starts
up fine but then the 12V sags badly or produces a lot
of ripple etc later. Not very likely to be that reproducible tho.

 

[juhani.jaakola]

Thanks for advice!

I tried to boot without the video card, and I got exactly the same
results: At first CD LED lights for a moment, then the HDD LED blinks
for couple of seconds, and then the floppy LED lights up and stays on
for ever. I re-inserted the video card and still the same results.

I measured the voltages from the power supply, and at least the 5 V and
12 V were OK.

My display stays blank all the time. I have tried another monitor and
cable with same results.

Shouldn't the POST produce beeps if something is wrong? Or is something
so badly wrong that the POST does not even start?

Any ideas?

 

[Rod Speed]

(e-mail address removed) wrote

I tried to boot without the video card, and I got exactly the same
results: At first CD LED lights for a moment, then the HDD LED blinks
for couple of seconds, and then the floppy LED lights up and stays on
for ever. I re-inserted the video card and still the same results.

I measured the voltages from the power supply,
and at least the 5 V and 12 V were OK.

My display stays blank all the time. I have tried
another monitor and cable with same results.

Shouldn't the POST produce beeps if something is wrong?

Nope, not if its a problem the POST cant see. Most obviously
with a problem on the output side of the video card or cable.

Or is something so badly wrong that the POST does not even start?

Very likely given that it didnt beep with no video card.

Any ideas?

Check for bad caps on the motherboard. Its looking like the
motherboard is the problem now, tho it could just be a bad
joint, cracked trace or even a short to case, which was
initially producing that need to reboot for a while, and which
has now got much worse and it wont even post anymore now.

It would be worth trying a different power supply if you can do
that for free, or measuring the grey wire in the ATX connector.
Thats the POWER_GOOD line and the power supply may not
be putting that up because its gone bad but is still putting the
12V and 5V rails up. That would produce the symptoms you
are seeing with the exception of the floppy light on all the time.
Its quite possible that that motherboard does that if it never
sees POWER_GOOD too.

If a power supply replacement doesnt help, of the POWER_GOOD
comes up fine, its almost certainly the motherboard thats failed.
Worth trying it loose on the desktop if it looks like a bad mb,
because thats the best test for a short to case which certainly
can happen, usually because someone has dropped a screw
and hasnt bothered to try and fine it.

 

[juhani.jaakola]

(e-mail address removed) wrote ....

Nope, not if its a problem the POST cant see. Most obviously
with a problem on the output side of the video card or cable.

I have tried with two different cables and monitors, same results.

There were dust in the heat sink of the video card, maybe it got fried?
However, when I took the card out I couldn't see any damage visually.
Would POST detect a fried video card?

Very likely given that it didnt beep with no video card.


Check for bad caps on the motherboard. Its looking like the
motherboard is the problem now, tho it could just be a bad
joint, cracked trace or even a short to case, which was
initially producing that need to reboot for a while, and which
has now got much worse and it wont even post anymore now.

I did not take the motherboard out, so I could see only the upper side
of it. I could not see any bad looking components.

There were dust in the heat sink of the processor too - could it be
fried? But if the CPU was fried, why the CD, HDD and floppy LEDs light
up in a sequence, can they do it themselves or is the CPU polling them?
And if I try to boot from a CD or floppy something seems to happen,
although I can't see anything on the monitor.

It would be worth trying a different power supply if you can do
that for free, or measuring the grey wire in the ATX connector.
Thats the POWER_GOOD line and the power supply may not
be putting that up because its gone bad but is still putting the
12V and 5V rails up. That would produce the symptoms you
are seeing with the exception of the floppy light on all the time.
Its quite possible that that motherboard does that if it never
sees POWER_GOOD too.

If a power supply replacement doesnt help, of the POWER_GOOD
comes up fine, its almost certainly the motherboard thats failed.
Worth trying it loose on the desktop if it looks like a bad mb,
because thats the best test for a short to case which certainly
can happen, usually because someone has dropped a screw
and hasnt bothered to try and fine it.

I'll try that when I get home.

What do you say, is it a good idea to try to reset the BIOS CMOS?

 

[kony]

I have tried with two different cables and monitors, same results.

There were dust in the heat sink of the video card, maybe it got fried?
However, when I took the card out I couldn't see any damage visually.
Would POST detect a fried video card?

The video card could be damaged such that a system might
post anyway, or it might not (depending on type and extent
of damage). However, we have no established there is
anything wrong with the video card, usually it is NOT the
video card, usually a system isn't outputting video because
it has failed to post, not failing to post because it isnt'
outputting video.

Having some dust in the sink (but fan working still) will
not typically kill a card like this if there were no other
signs- but you did have the lockups periodically in the
past- which may or may not be related to the problem now.

Did you ever mention your hardware liike the PSU? Could
easily be poor, overwhelmed, or just a random failure. If
PSU was bad enough, it could even damage other parts, but
this would be jumping to conclusions prematurely, if you
have a multimeter take voltage readings, especially when the
system is stuck in the failing-to-post state or when it has
frozen up.

I did not take the motherboard out, so I could see only the upper side
of it. I could not see any bad looking components.

The most commonly failed caps are around the CPU socket and
behind some inductors... some of the largest caps on the
board.

There were dust in the heat sink of the processor too - could it be
fried? But if the CPU was fried, why the CD, HDD and floppy LEDs light
up in a sequence, can they do it themselves or is the CPU polling them?

Devices lighting up can do so merely when ready to operate
after a power-on. However, your initial description of the
power on then floppy access seemed to coincide to what
happens when a system cant load the bios properly and
defaults to a state of trying to emergency flash a bios from
a floppy. However, since the system did previously have
problems it may be a false logic from the board, the bios
might be ok and it's just doing this as was programmed.

If all else fails, do try to find the correct emergency bios
flashing procedure for your board/bios and put such a
constructed floppy in the drive. For the time being, take
out the battery and check it's voltage, and clear CMOS (with
AC power disconnected from PSU).

Try the suspect video card in another system, or another
known good video card in that system.

It is not likely your processor is fried, unless the fan had
failed. Assume it is fine until you have more reason that
stated- any typical system will have a little dust buildup,
unless it was extreme it is not going to manifest in a
complete failure to post with a cold system. Systems now
have overheat shutdown anyway, you should have had more
warning... but you also should have investigated the
periodic freezeups previously, it might have been easier
while system was still running somewhat, "IF" it is a
related cause. For now, assume the CPU to be the least
likely problem.

And if I try to boot from a CD or floppy something seems to happen,
although I can't see anything on the monitor.

What seems to happen?
With AC unplugged, pull out the video card, inspect again
and reinstall it. Make sure it is lined up straight with
the slot, if your motherboard isn't mounted quite right in
the case it may put the slot at wrong position relative to
the card bracket. It would be easier to just try another
video card if you have one available... even an ancient 1MB
PCI card would suffice, and is actually ideal since it is
legacy and low power.

I'll try that when I get home.

What do you say, is it a good idea to try to reset the BIOS CMOS?

yes that would typically be the second thing to try, after
first unplugging the AC power for 10 minutes and retrying
it.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed wrote

I have tried with two different cables and monitors, same results.

Sure, that was just a general comment on what appeared to be a general question.

There were dust in the heat sink of the video card,

Thats normal, there always is in any heatsink that been used for a while.

maybe it got fried?

That doesnt usually produce a post beep, it usually just
produces odd effect on the image like color streaks etc.

However, when I took the card out I couldn't see any damage visually.

Its hardly ever visible unless its got very badly fried.

Would POST detect a fried video card?

Often it doesnt, because its behind what the POST can see.

I did not take the motherboard out, so I could see only the upper side of it.

Thats fine when checking for bad caps.

I could not see any bad looking components.

There were dust in the heat sink of the processor too

Thats normal, there always is in any heatsink that been used for a while.

- could it be fried?

cpus dont usually get fried if you dont
overclock and the heatsink hasnt come off.

But if the CPU was fried, why the CD, HDD
and floppy LEDs light up in a sequence,
Indeed.

can they do it themselves
Nope.

or is the CPU polling them?
Yep.

And if I try to boot from a CD or floppy something seems
to happen, although I can't see anything on the monitor.

Does that happen for a considerable time tho ? Floppy boots particularly
take a surprisingly long time when you are used to hard drive boots.

I'll try that when I get home.

What do you say, is it a good idea to try to reset the BIOS CMOS?

Yes, well worth trying.

 

[juhani.jaakola]

The problem is solved now. I could get an old PCI video card and when I
replaced my old card with that the system booted fine! I bought a new
video card and a new fan for the case and now the system works again!

Thank you all for help!

 

[Rod Speed]

The problem is solved now. I could get an old PCI video card and when
I replaced my old card with that the system booted fine! I bought a new
video card and a new fan for the case and now the system works again!

Thank you all for help!

Thanks for the washup, too rare in my opinion.

 

[kony]

The problem is solved now. I could get an old PCI video card and when I
replaced my old card with that the system booted fine! I bought a new
video card and a new fan for the case and now the system works again!

Thank you all for help!

Good to hear it is working again and thank you for posting
the solution.