VOGONS


First post, by Gazirra

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I've recently completed a WIN98SE system, and I had a spare AGP GPU that may or may not work, so I tried to install it into this system. I had removed its heat sink and reapplied some thermal compound, thinking it may be related. I had also checked my CPU to ensure it was also set with the compound. I put everything in, moved the BIOS reset jumper to the "reset" configuration, then put it back into its normal place (or so I thought). I then tried to power up the system, and nothing happened. Up until this test, it worked just fine.
When I checked the system, it turns out that I had forgotten to put the jumper back into its place for normal operation. I put it back, then tried the power, and got nothing, again. I'm nearly 100% sure it's the MB due to this jumper, but I don't see any problems with the capacitors and nothing else jumps out at me regarding the MB.

My normal configuration is:
AOpen Ax6BC
Pentium II 350
512 M RAM
YMF72F sound card
ATI Rage 128 PRO PCI GPU

The alternate card was an AGP MX4000/128MB

If it were the MB, is there any chance in hell I could repair it?

Reply 3 of 15, by Gazirra

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retardware wrote:

When you manually short the power on jumper on mobo, nothing happens?

I feel dumb for asking, but what are you referring to, exactly? I didn't see that jumper in the MB manual

Reply 5 of 15, by Gazirra

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retardware wrote:

Looks like a strange mobo. It has only a "sleep switch".
What happens if you short that one?

Nothing. That's also where I think I had originally had the power switch connected

Reply 6 of 15, by retardware

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If it does not power up using another known-good PSU, I'd suspect the board needs repair.
Some really do not like being powered while CMOS power is shorted.
As this board is not really old, I'd consider replacing it.

But, maybe one of the repair gurus here is in the mood...

Reply 7 of 15, by Merovign

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How many of the components can you replace for purposes of testing?

The "power jumper" is where the power switch plugs into the motherboard, BTW.

It's possible to repair almost anything, in theory, it's just whether it's worth it.

Eventually someone will tell you to check for bad caps, particularly power filter caps, though this can be hard to do. Often they bulge at the top, but not always. Some component or another could have been kicked over the edge from functional to non-functional during the problem.

*Too* *many* *things*!

Reply 8 of 15, by jesolo

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Just to be sure, start off by testing the PSU: https://www.instructables.com/id/How-to-power … y-without-a-PC/

I recently had a "dead" motherboard (Socket 775) and later on discovered it was actually the 4 pin connector that powers the CPU that had a problem. Eventually turned out to be a capacitor and MOSFET around the CPU area (where it gets very hot) that had to be replaced.

Reply 9 of 15, by Deunan

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Gazirra wrote:

I then tried to power up the system, and nothing happened.

Can you elaborate? What is "nothing", exactly? Did the PSU fan start and in general it looked like it's powering the mobo but there was only black screen, or was there no reaction to the switch at all?

If the PSU is working, check the voltage between the 2 pins that were shorted in oder to clear CMOS. Just be careful not to short them out again with probe leads.
On the other hand, if the PSU is not starting but otherwise checks OK with another mobo, then I'm afraid you've most likely burned out some copper on this one. Sometimes it can be repaired but the hard part is to actually find the fault - and it can be inside the PCB (inner layers).

Reply 10 of 15, by varrol

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I have AOpen AX6B and sometimes have problem booting it up - same effect - will not boot at all. The solution is to replug power supply - then it starts without a problem.

But before plugging it back again, just short ground with start pin to check is PSU actually starts.

I'd also remove battery for a while - don't suppose that would help, but won't hurt.

AOpen AX6B+ | P3 1G | 1GB ECC REG | FX5200 | CT4500
AOpen AX59pro | K6-2 450M | 256MB | Rage 128
Asus CUBX-E | P3 1G | 512MB | GF4 TI4200 | YMF719E-S
Asus P3B-F | P3 933M | 384MB | Radeon 9200 | CT4520
Asus P5A | P55C 200M | 256MB | Riva TNT | CT3600

Reply 11 of 15, by Gazirra

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Deunan wrote:
Can you elaborate? What is "nothing", exactly? Did the PSU fan start and in general it looked like it's powering the mobo but th […]
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Gazirra wrote:

I then tried to power up the system, and nothing happened.

Can you elaborate? What is "nothing", exactly? Did the PSU fan start and in general it looked like it's powering the mobo but there was only black screen, or was there no reaction to the switch at all?

If the PSU is working, check the voltage between the 2 pins that were shorted in oder to clear CMOS. Just be careful not to short them out again with probe leads.
On the other hand, if the PSU is not starting but otherwise checks OK with another mobo, then I'm afraid you've most likely burned out some copper on this one. Sometimes it can be repaired but the hard part is to actually find the fault - and it can be inside the PCB (inner layers).

"Nothing" here indicates that there is no response from the system. I press the button, and the system just sits there with no activity whatsoever

Reply 12 of 15, by chinny22

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First thing to try is remove everything accept video and 1 stick of ram.
System doesn't power on? try again replacing one of the 3 each time. (and CPU if you have a spare)
If you still don't get anything you know its the CPU or M/B.

Reply 13 of 15, by Orkay

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A surefire way to know the state of the motherboard is to plug in a cheap POST diagnostic card, preferably one that allows for connecting an external display. If you see no codes being displayed (the dreaded four hyphens in my picture), that's often a sign the motherboard has failed unless the CPU has gone bad somehow. Of course, not receiving any POST codes can also be annoying since it's unclear what is preventing the board from POSTing; it could be anything, really.

I've run into a similar problem with my AOpen AX6B Plus I got recently. I put it in one case and it POSTed twice, although it didn't accept any keyboard input. When I moved it to another case, the board stopped POSTing. Two attempts to power on the system did return a single code C0, likely meaning the board attempted to initialize some devices but immediately fell out of it.

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Reply 14 of 15, by SirNickity

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Try replacing the CMOS battery. I've had TWO boards now (three, actually, but two were the same model) play dead when the battery went flat, and wouldn't power up without a battery either. Put a new coin cell in, and it was up and running like I wasn't just planning its funeral... One was dead from the moment I got it, but the other decided to go AWOL during a brief tear-down to swap optical drives. Worked when I shut it down, wouldn't power up after I put it back together.

I never would have guessed before this.

Reply 15 of 15, by Orkay

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I've been using a new CMOS battery, and even tried powering it up without one, no difference. I read in a manual for a similar board that AOpen has implemented a "batteryless" design, where settings could be stored and loaded from an EEPROM instead of the usual battery-powered RAM. This board is in need of some kind of repair that requires soldering, and I've still yet to get around to learning how to do it... as well as understand what extra materials I really need to do it safely.