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Discussion Starter #1
Hey-- Well, now what happened?!! Booted up my XP machine and got absolutely no display at all! Swapped the monitor to my W98 machine and it displayed (monitor ok). Took the video card out of XP and put it in 98 and it displayed(video card ok), but the card that was in the 98 machine(working video card) did not display in XP. All the fans are spinning on XP so it is getting power I guess. I can't use any software to look at voltages, no display! How would I check PS voltages? I wonder if it is a PS problem? I just installed this Ultra 500W PS about 90 days ago. Any ideas? :4-dontkno
 

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EJayJay said:
Hi again guys and gals. I tried clearing CMOS as was suggested in my last post and it did not help a'tall. Still absolutely no display. Please see the previous post pertaining to this problem. I really need some serious help. I also do not know how to keep a dialogue going in a post. If I post a reply, I may not get another answer because my post moves too far down the queue. :4-dontkno
 

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I wonder if it is a PS problem? I just installed this Ultra 500W PS about 90 days ago.
You didn't mention trying the video card in other slots so it appears you are using AGP video cards. It's possible the AGP slot has failed, see if you can borrow a PCI video card from someone to try the PCI slots for video.

The fans use the 12Volt line and video cards typically use the 3.3V and 5V lines, so we know the 12V works (enough to power fans at least) but one of the other voltage rails may be dead or deficient. Did you hear/feel the drives spinning up when powered on?

The CPU should detect a problem with video communication and beep an error code, the absence of 'beep errors' suggests the CPU/mobo is not being powered properly or the CPU has failed.

The rule of thumb on electronic devices is 'if faulty it will probably fail within the first 3 months of use'.

If you have a multimeter, (or can buy an inexpensive one), you can test the PSU voltages...
http://www.techsupportforum.com/showthread.php?t=65936

.
 

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Discussion Starter #5
I did try a pci slot video card -- no display! I'm going to try to take some PS voltage readings later today. Again, thanks for the help. I will post again later today. :4-dontkno
 

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Discussion Starter #6
big problem with display

OK, here are the results of the voltage and ohms readings I took today. By the way stu_computer, an excellent post on troubleshooting! All readings were taken following instructions in the above mentioned post;
pin 9 = 5Vdc pins 1,2,11 = 7 ohms
pins 1,2,11 = 3.3Vdc pins 3,5,7,13,15,16,17 = 0 ohms
pins 4,6,19,20 = 5.2Vdc pins 4,6,19,20 = 41 ohms
pin 10 = 12.1Vdc pins 8,10,12,14 = infinate ohms
pin 18 = (-)4.91Vdc pin 9 = 96 ohms
pin 12 = (-)11.56Vdc pin 18 = 145 ohms
AC Gnd pin = 0 ohms

Voltage readings look ok, but some of the ohms readings are not correct.
More test results;
Pin 8 = 5.2Vdc when pin 14 was at 0Vdc. Pressing reset button did not change V on P8.
With meter lead on pin 9 and PS AC switch OFF, 0Vdc on pin 9. This next step is weird---with meter on pin 9, when turn on PS AC switch, the CPU fan and other fans spin up for just a second and then stop. Pin 9 will rise to 5.1Vdc.
Pin 14 is 4.91Vdc, and when case POWER ON is pushed, pin 14 drops to 0V.
With PWR_OK at 0V, pin 8 = 5.2Vdc. Pressing reset button did not change the voltage on pin 8 at all.
There is a problem somewhere, but I believe I've ruled out a PSU problem.
If any of you major gurus have any other ideas or suggestions based on the above data, I'm all ears! As usual, thanks for your help and input. :4-dontkno
 

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Discussion Starter #7 (Edited)
one dead and buried mobo?

Well, I've done all I can do to get a display up, to no avail. I was planning on swapping mobo & procesor anyway as mentioned in a previous post. I was leary about doing that then and am even more so now not knowing what is causing the display problem. I really wish I knew what the problem is. It would be better knowing rather than jumping into this swap-out blind. Still, if anyone has any other ideas or can decipher my post here, please let me know. I have purchased a new mobo and processor, but will probably take a few days to arrive. :4-dontkno
 

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With PWR_OK at 0V, pin 8 = 5.2Vdc.
The CPU is active or you wouldn't get these readings.
Pressing reset button did not change the voltage on pin 8 at all.
Verify the Reset switch works, and is plugged in the right location. You can try a screwdriver tip or a spare jumper from a hard drive, (or paper clip etc...), to short the Reset pins together to see if Pin 8 goes low.

At this point it appears the motherboard is faulty.

Is this a new system your putting together?
Some details will be helpfull...
(brand and model)
motherboard
CPU
Ram
video card
hard drive
 

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Discussion Starter #9
No, not a system I'm putting together. This is my current system that is giving me fits. I am going to upgrade in a few days with new mobo & processor, and swap over all my current components. I have made certain the other components will be supported and they will, including memory and a new (90 day old) Ultra 500W PSU. That is why I wanted my display back, so I can be sure all the other current components are still good. Everything was fine until I rebooted the other day and got no display! The only reason I rebooted was after downloading an update to my virus scan program. I suspect the mobo may be bad, I have suspected a flakey mobo for a while. Bad timing for it to die now, simply because of the fact I would like to know for certain all other components are still ok before swapping.
I am going to test the reset swith and a couple other things. As usual, thanks for the help and input.
 

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Discussion Starter #10 (Edited)
Well, I removed the processor from its socket as was recommended in the troubleshooting link and ohmed all the Gnd pins. All read 0 ohms. Here is a big part of the problem, although I still don't know why or how to fix it. When pin 8 has 5Vdc and I press reset, that V does not drop. When I short the reset pins on the mobo that V does not drop. It is supposed to go to 0V and then return to around 5Vdc when reset is released (not shorted), correct? It does not. Also, as mentioned previously, whenever I switch on the PSU AC switch, all the fans start up for a second or so and then stop. That should not be happening! They should spin when the CASE power button is pressed on,NOT in the situation just described. That , too, is a big part of the problem! :4-dontkno ......but I do not know why.
A couple questions and I am going to let this go. First, is there a way to check for SHORTS on the mobo, or would that be beyond the scope of this forum?
Secondly, as previously mentioned, I am going to install a new mobo and processor shortly anyway. Based on the data in this thread, would YOU feel fairly confident at this point about making the aforementioned uprgade? Tell the truth. I'm not going to hold you to anything!! -razz:
Any further ideas, if possible, would be appreciated. And again, thanks for your help and input. :smile:
 

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When pin 8 has 5Vdc and I press reset, that V does not drop. When I short the reset pins on the mobo that V does not drop. It is supposed to go to 0V and then return to around 5Vdc when reset is released (not shorted), correct? It does not.
Although that is what should happen, the fact that it didn't suggests the mobo manufacturer has likely used a different method to trigger Reset-it's not that uncommon. It means we just can't verify the CPU Reset signal using Pin 8 to know the CPU is actually being signaled to reset.

We do know the CPU is active because Pin 14 went low and Pin 8 high, (but that doesn't prove it's fully functional). Also, there is no short circuit, otherwise the PSU would shut down.

Have you tried the usual checks?
-verified all PCI/AGP cards, ram and bios chip are properly seated.

-hold down bios setup key (** Del, F1, F2, Ctrl-Home, etc...) while starting computer.

-put a floppy diskette in drive to see if computer tries to load bios flash utility. Repeat while pressing bios flash keys (** Ctrl-Home, F12, Ins, etc...) **Re: check motherboard manufacturer for details.

-removed video and ram to check for beep errors-no beeps suggest a bios or board fault.

-removed mobo from case to visually inspect it for cracks, leaky/deformed capacitors, burnt or melted spots.

-set mobo on cardboard with ram and video installed, connect video and power up to check if posts when not stressed by chasis mountings-some heatsink designs cause the mobo to deform. Note: Can repeat this with setting up beside your Win98 pc and use it's PSU and monitor to check if mobo starts-eliminates the XP's PSU as a suspect.
Also, as mentioned previously, whenever I switch on the PSU AC switch, all the fans start up for a second or so and then stop. That should not be happening! They should spin when the CASE power button is pressed on,NOT in the situation just described. That , too, is a big part of the problem!
Your previous post implied the fans were running when powered on. Are you now saying that they only come on momentarily when power applied but don't run when CASE power button is pressed?

You cleared the CMOS, assuming it's functional it may be the default setting.

Do a power supply reset by unplugging the power cord, and pressing the CASE power button for 15 seconds.

PSU's require a minimum load to function properly, for a low wattage PSU the mobo and video card are usually sufficient. For PSU's larger than 400W leave a CDrom drive's power cable connected.

A couple questions and I am going to let this go. First, is there a way to check for SHORTS on the mobo, or would that be beyond the scope of this forum?
There's no bolted short (direct circuit to GND) in the mobo/peripheral devices, that would cause the PSU to automatically shut down. It would more likely be an open circuit caused by a failed component or trace breach in the board. You would need an identical board to make comparative readings.
Secondly, as previously mentioned, I am going to install a new mobo and processor shortly anyway. Based on the data in this thread, would YOU feel fairly confident at this point about making the aforementioned uprgade? Tell the truth. I'm not going to hold you to anything!!
Any further ideas, if possible, would be appreciated. And again, thanks for your help and input.
The PSU appears to be okay, and you already tested the video card, so the only unknowns are ram and drives. It would be a good idea to test the ram in another working computer if possible before using it in a new setup, so you know it's okay.

Also, I would test the hard drive for virus before using it or trying to recover data.
 

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Booted up my XP machine and got absolutely no display at all! Swapped the monitor to my W98 machine and it displayed (monitor ok).
you never mentioned what monitor you are using...i have a compaq that wont work with my xp but will with my 98se...plug and play...yup
 

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That's a good point, Rich.

Monitors and CD/DVD burners can sometimes be a problem with XP. Though I think Jay's been using this pc for a while before this problem came up.
 

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Discussion Starter #15
Computers---Can't live with 'em, can't live without 'em!

Good post again stu_computer. Have not yet tried all you suggest in that post. I'm sure if the mobo comes out of the case the new one (due in next week) will go back in. Some other things I have done just before this problem started. Ran Memtest86 for several passes with no mem errors; daily Viruscan, Spybot, Ad-Aware, MS Anti-Spyware checks, all of which showed no major or serious intruders. I also inspected the mobo while in the case with a VERY powerful flashlite (Surefire?) and could detect no signs of any damage. Couple other things; mentioned the monitor was ok in initial post, I'm using it on this machine now ( now using AMD K6 on Win 98). Not sure how to clarify the thing with the fans. They DO run when I power on the machine as they shoud and stop when power off. On the HD (2) I honestly can't tell if they are spinning up or not when I power on the compuer.
As this is the weekend and this old AMD K6 is getting me on-line AND the Bud is getting cold in the icebox, it will probably be next week before I post back. Again, thanks for the help and input and have a great weekend. :grin:
 

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Discussion Starter #16
I must confess

....I really believe now that the mobo is bad. I am going to just do the swap out when all components arrive, and just junk this mobo! Thanks for all yer help and input. I think we can close this thread.
 
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