mobo intermittent problem on P.O.S.T. 1

[barny2006]

Hi,
here's a scoop on what's happened with my home-built pc:
1 - mobo is asus p5RD1-V
2 - cpu is p-4 2.66 ghz socket lga775
3- 2 hdd's, one cdr, one dvdr - all via IDE cables
4- hp printer via usb
5- camera card reader via usb
6- webcam via usb
6- mic, speaker
7- onboard lan, sound and video
8- system had original 1 stick of ram - 256mb
9- installed another 256mb ram of same kind and speed
10- installed 512mb ram of same kidn and speed
11- the system worked find until recently. and here's what it does:
1- on power-up, (p.o.s.t.) the mobo logo freezes and would not continue. there are horizontal lines across the mobo logo. and a continuous beep is heard. this doesn't always happen.
when the pc is turned off once, twice or 3 times, it goes on to windows.
2- sometimes it says: overclocking failed, press f1 to go to setup, pf2 to continue with defaults.
3- sometimes it gives error msg: cmos checksum bad.
4- sometimes it goes straight to windows after 3 or 4 times turning pc on and off.
5- the memory is total of 1024mb, however, when i go to "my computer", it shows 960mb (64mb is missing).
6- it seems that the pc is forgetting the cmos seetings or something.
7- if i shut the system down, and turn it on immediately, there are no problems, only when i wait 10-20 minutes, this problem happens.
i have:
- replaced the cmos battery. it shows over 3 volts
- cleared the cmos (moved jumpers to pin 2 and 3 to clear
and then back to normal (1 and 2 pins)).
- downloaded bios from asus site and updated the bios.
- still same problems.

any ideas why it's doing this? is it cpu? mobo? ram? hdd? or what?
thanks!

 

[stduc]

The trick when troubleshooting issues of this kind is to isolate the problem.

It could be a PSU issue as well. Ensure the power rating is well in excess of requirements and that it is a branded model. No-namer PSU's are notorious for causing problems. A crude way to see if it is the PSU is to remove all cards & drives to reduce the load (except the video card of course) and see if the problem goes away. If it does, it is either one of the cards/drives or the PSU.

Check the RAM.

Download memtest86 and build a bootable media (floppy or CD as suits you best)

Test each stick in turn and then together if the sticks seem good. Throw any stick memtest86 reports as bad.

If the RAM seems good, remove all cards and drives except the video card and see if the problem goes away. If it does, replace one component at a time to see if you can discover the cause of the problem.

If still no joy, try removing and re-seating the CPU (Use a new heat pad).

 

[micker377]

I don't know about the rest of the problems, but the "missing" memory is normal, "shared" memory that is used by your on board video. Now for the hard part: look for leaking or bulging capacitors. Most of the caps will look OK (flat or slightly depressed tops some with an "X" or "Y" stamped in them). Any bad ones will have the tops bulging upward.

 

[barny2006]

thanks stduc,
for that detailed info. i think you may have hit the nail on the head. i was looking at the voltage info on asus probe (a mobo monitor), and it shows 2.92 volts for something that needs 3 volts. it shows 4.94 volts for something that needs 5 volts and so on. i'm goint to re-seat the cpu first, (because there's no epxenses involved. then i'm going to put a new power supply and see what happens.
p.s. i test the ram sticks in another machine, and they did ok.
thanks again.

 

[barny2006]

problem solved.
the problem was from the power supply unit, just like i posted about the required voltages being less and as stduc suspected. i put a new 500 watt power supply unit, and the pc booted up with no problem whatsoever. i repeated it several times, and every time it booted clean with no errors.
thanks stduc.

 

[johnbullas]

http://dlsvr02.asus.com/pub/ASUS/mb/socket775/P5RD1-V/e2046_p5rd1-v.pdf

BIOS is an AMI BIOS AFAIK

http://www.bioscentral.com/postcodes/amibios.htm

http://www.bioscentral.com/beepcodes/amibeep.htm

..... sadly no sustained beep

both of these pages might help out in future

Beep Codes generally

http://www.pchell.com/hardware/beepcodes.shtml

JB

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Transportation Research Consultant
Winchester UK