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puffpuff
26-06-2008, 01:39 PM
Hi all.I've got a problem that I hope someone here might be able to help me with.I was given a system box,which I know had been working perfectly at my daughter's place.
Upon getting it home,I plugged it in,and got a "no video signal"message on screen.After a few re-starts,system booted,and worked normally.Next day,when started,nothing on screen at all.The hard drive is running,as are all fans.The monitor light stays yellow,instead of going green after a normal start up
I searched google for"no display",and came up with the following :
Switched monitor with known working one:no result
Removed graphics card and replaced with known working one:no result
Removed and reseated RAM:no result
Replaced bios battery(CR2032)on motherboard:no result
Restarted while pressing F8 for safe mode:no result
One site mentioned re-setting the bios via the jumper,but I'm loath to try this,as I don't know how to reload bios.
I'm at my wits end with this thing.Is there anything I've overlooked?
Has the motherboard itself died?
Here are the specs of the system,if that is any help:

DFI AD73 Pro motherboard-Athlon XP1800+
GeForce MX400-64MB graphics
512 MB DDR ram
Running Win 98

I've managed pretty well with computer problems in the past,but this one has me scratching my bald patch,which is now extending by the day:(
Sorry for the long post,but I was trying to supply as much info as possible.
Thanks for your attention.John.

pctek
26-06-2008, 01:51 PM
"no video signal"message on screen.
Switched monitor with known working one:no result
Removed graphics card and replaced with known working one:no result
Removed and reseated RAM:no result
Replaced bios battery(CR2032)on motherboard:no result

.

What does no result mean exactly? You mean you did all this and it still give no picture at all?

Or it gives a picture sometimes?

I'd say, if no picture still, then you have eliminated everything except the motherboard.

puffpuff
26-06-2008, 02:06 PM
Perhaps I should have said "no improvement",but you're right,absolutely no picture at all.John.

Agent_24
26-06-2008, 02:27 PM
Replacing the battery might have cleared the BIOS settings too... you don't need to reflash or anything if you clear the BIOS, it's just the settings that get reset.

But to ensure it has been reset, use the jumper.

Going by the specs of that system, it could be bad capacitors. do any caps on the motherboard or video card look like these?

http://en.wikipedia.org/wiki/Capacitor_plague

If not, it could be the PSU. Have you tried using a known good power supply?

pctek
26-06-2008, 07:37 PM
If not, it could be the PSU.

I doubt that. A stuffed PSU isn't going to boot the rest of the PC and not the graphics card.


It is booting right? Like you hear the HDD power up etc?

If all the testing was done with known good parts - then it leaves the motherboard - AGP/PCI-E slot............

beama
26-06-2008, 07:53 PM
Ive had this happen before and it it turned out to be a software problem. The os had corrupted. To test this theory try booting with a linux live cd if you get a display suspect corrupt software if not go back to your hard ware.

BTW
does this pc have an on board video card if so is it disabled in the bios because you are using a addin card

puffpuff
26-06-2008, 08:24 PM
Yes,it is definitely booting up.I'll have another go at resetting the bios.I
read somewhere that you can reset by leaving the battery out for at least a minute.Worth a try,at least.John.

Grimy
26-06-2008, 08:33 PM
When switching on do you get a POST beep?

autechre
27-06-2008, 09:03 AM
Ive had this happen before and it it turned out to be a software problem. The os had corrupted. To test this theory try booting with a linux live cd if you get a display suspect corrupt software if not go back to your hard ware.

Any software problem will not affect the display before the OS starts booting. You should still be able to see all of the POST information before the OS starts.

In this case it looks like the AGP slot has died. I guess if you can't see the BIOS it makes it difficult to change any settings, but you can change a setting to use PCI video cards instead of the AGP.

beama
27-06-2008, 12:23 PM
as I said before Ive had machines do exactly this and its been a software fault not all machince display post info on boot

drcspy
27-06-2008, 12:35 PM
i'm goin to suggest that as the thing has travelled if you have a pci or agp video card that you pull it out then firmly reseat it.......could have moved in it's slot it's not unheard of

smokey
27-06-2008, 01:04 PM
Yes,it is definitely booting up.I'll have another go at resetting the bios.I
read somewhere that you can reset by leaving the battery out for at least a minute.Worth a try,at least.John.

would suggest you leave battery out for half an hour. it sometiems takes quite a while before bios is reset.

Agent_24
27-06-2008, 01:08 PM
or you could just use the jumper which would take all of about 10 seconds

puffpuff
27-06-2008, 01:13 PM
IT'S FIXED!!!
drcspy's post set me thinking.When I first opened the case to remove the dust,I noticed the graphics card wasn't attached to the back pane,so being the diligent type,I fitted one.
Turns out that was my mistake.I tried fitting a pci type card this morning,and then realised I couldn't get into the bios anyway.So removed,and refitted the original agp card.I didn't fit the screw at this stage,as i was pretty well convinced it had to come out again.
Lo and behold,it sprang to life,and goes like a rocket!
The L bracket on the graphics card doesn't quite line up with the screw hole,and by fitting the screw,it must have moved enough to disengage the card.
This is the first time I come across this sort of idiotic manufacturer's fault.
Something to file away in the troubleshooting files.
Thanks to all you guys who racked your brains trying to help me sort this problem.:) :) :)

drcspy
27-06-2008, 01:21 PM
excellent

ps: see my signature lol

puffpuff
02-07-2008, 09:59 AM
Goshdurnit,It's up to it's old tricks again.Same problem,one long beep,repeated every few seconds,"no display signal"message.GGGGGGGGG%RRRRRRRR.
I'm going to try replacing the power supply,as i have a spare.You never know.