EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: FileNotFound__ on June 29, 2022, 05:07:57 pm
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The PC works, every other time.
When I try to start it, the fans and the harddrive spins up, but there is no disk activity or anything.
When I try to restart it, it boots up just fine.
I tried switching the power supply and the ram but it didn't help.
I concluded the issue is the motherboard, because in the system there is no external graphics card or anything else that could cause no POST.
I am hoping, since the board is half working if the issue could be fixed, if it could be a capacitor or something I could easily replace.
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Firmware (BIOS in older motherboards) falling back to default/safe settings after a failed boot, allowing one start to correct invalid configuration and then using the incorrect options again?
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I am not getting any messages or anything about the cmos being reset, time and settings are beeing saved.
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During POST or in setup? I never seen anything like that being reported during POST either. It “just happens”: the system doesn’t boot, restarts, “safe” settings are used. I could only tell because there is a warning about that in the configuration.
But if it’s not firmware trying to restart into safe configuration, I don’t have other ideas to offer. Other than asking, if there actually is a pattern: how many times did you try and did you observe exactly that behavior every time, with no single exception?
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I agree with that it may be bad BIOS/EFI settings causing the failure and a fail-safe default that works on the second try. Get into the BIOS settings and load defaults, set important things (date/time, SATA mode, boot device) then save, reboot and see what happens.
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When the sytem detects an issue, it usually trows up an error like the one in the picture (not the same system) and asks you to reconfigure it.
"if there actually is a pattern: how many times did you try and did you observe exactly that behavior every time, with no single exception?" Well, it happens every time I try to start the system, it turns on, and does nothing, reset button does nothing, holding the power button turns it off, and then it starts just fine on the next attempt. This isn't a power cycle like ram training or failsafe, it just turns on and does nothing untill iI force it to turn off. There were some exeptions but they are rare. Exiting the bios also breaks it.
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Loading optimised defaults did not help
I just read that my CPU does not have integrated graphics, instead the motherboard's chipsets is used as the graphics card. Could that be the source of my problems?
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update latest BIOS yet, ensured good coin cell battery V?
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Modern motherboards perform ram training in the first moments of startup. Sometimes they save good configs, sometimes not. Perhaps try reseating the ram, trying only a single stick, trying it in a different slot or trying different RAM?
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Check the BIOS battery
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OK, the BIOS battery was a bit low at 2.5V, but replacing it did nothing exept resseting the time.
I got A BIOS POST card from a technician nearby, the code stops on 50 when it gets stuck
I tried different RAM configurations, and no changes.
The technician also gave me his testing GPU, and the system with the GPU installed never posts and gets stuck on 50 or d3.
It also stopped once on code 41 when I tried to unplug the GPU and plug it back in. And It might have stopped once on d1 with the gpu in alltough it might just be my imagination.
in the picture attached is the manual of the post card and the codes it gave me, not sure witch one should I look at.
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If it's intel CPU (LGA package), try cleaning its pads with alcohol. Also look for bent pins in the socket.
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It is an AMD system, the pins look straight
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After torturing it on the bench with a hairdryer, contact cleaner, forgetting to plug the cpu fan back in, it now starts every time.
I don't know what I did, but it works now.
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Hairdryer helped? If there are any electrolytic capacitors, check them for signs of leaking or bulging.
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Maybe it just wanted to be tortured.
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All the capacitors look fine and now it even works when cold
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I wonder if the drier blew some conductive debris that was intermittently making contact...
Also, always suspect the power supplies - sometimes they can lead to these annoyances if they are on the edge of failure, especially since their capacitors are subjected to a lot of thermal stress.
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Could be the debre, but not the power supply, the power supply in the system has been recapped few months ago wheen I built the system.
I also Have 2 Power supplies I use for testing, it behaved the same across all 3 of them