How to test a mother board 1

[yourkeylady]

I've got a problem with my pc powering up but no bios start.

I checked the cables by replacing them with some from my working pc.

I've replaced the processor and fan. Took some ram out of a functioning pc and put it in, but still no startup messages.

I took the hard drive out and put it in my functioning pc and it boots fine. And I can hear the harddrive spinning when plugged into the broken pc.

The screen is a new flat screen. So, I know it works. So I put in a different video card in the old pc. And last of all I bought a new battery for the mother board.

Still nothing on the screen. I'm out of ideas. I did order a new mother board. But I ordered the wrong one with the wrong kind of ram. So it would be a big downgrade.

Does anyone have any ideas fix this?
It's a Slot A 462 processor with DDR ram.

I'm out of

Thanks
Tricia

 

[electronicsfreak]

On the motherboard, make sure the 4 or 8 pin connector is also connected. Not just the big power cable.

If they are , get a power supply tester and test your power supply. If it shows fine, rma your motherboard if a bios rest does not work.

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[edfair]

With all the integrated stuff on modern M/Bs there is a lot less testing available than there used to be.

About the only thing that I would be able to look at would be the address and data lines with a logic probe to see if the processor was clocking. That after attempting to power it up with a screwdriver blade across the power up connector on the off board headers, assuming that the low voltage standby circuit was getting power.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[Freestone]

Check your motherboard for possible bad capacitors:

http://www.badcaps.net/

 

[southerly]

What model PC is this?
I recall having a similar problem with a 2nd hand Gateway tower and the problem that the PC needed to have at least one memory stick installed.

 

[Sleepsalot]

First thing I do if one won't post is pull the cmos battery and short the 2 battery clips with it out, This will clear the cmos just in case some thing changed.

Life is a big Roleplaying adventure.

Wayne

 

[G0AOZ]

A little history may help us...

1. Is this a new build, or has it been running previously?

2. If running previously, do you think anything obvious might have caused it to stop working? Mains power failure, lightning strike, etc.

3. "I've got a problem with my pc powering up but no bios start.". So presumably fans all run, front panel power l.e.d. lights up ok, CD tray opens, etc., etc?

4. Try a known good replacement PSU that has an equal or higher Wattage rating.

5. Is it possible a screw has rolled under the motherboard and is shorting it out?


ROGER - G0AOZ.

 

[HalComps]

I'd go with sleepsalot, 1st port of call to be honest. does the PC boot up as normal without any other problem? could always get a new bios chip from the manafatures or get a new motherboard which might be easier

 

[gbaughma]

They actually have a diagnostic card that will plug into a PCI slot, and show you exactly what's going on during POST. I used to use one all the time.



Just my 2¢
-Cole's Law: Shredded cabbage

--Greg

http://parallel.tzo.com

 

[electronicsfreak]

gbaughma, you wouldnt happen to have a link to this card would you?

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[yourkeylady]

I've ordered a diagnostic tool that plugs into the printer slot. Anxious to see how it works.

Thanks
Tricia

 

[Sleepsalot]

Hi electronicsfreak,
This is one

http://www.amazon.com/Startech-com-PCIPOST-Post-Diagnostics-Test/dp/B00006B8EZ

This on in UK

http://www.cfide.co.uk/pci_post_display_card.shtml

another UK one

http://www.millennium-solutions.co.uk/diagnostic-tool-pc-computer/post-probe-code-reader-card.html

Hope that helps

Life is a big Roleplaying adventure.

Wayne

 

[electronicsfreak]

Star sleepsalot, thanks!

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon