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June 8th, 2023 07:00
Optiplex 7060 With No Power
Good afternoon all.
I wonder if anyone has any thoughts on this, as I have never had a hardware diagnostic fox me as much as this.
PC will not turn on, no power at all, no LED in the power switch and no beep code.
You would say 100% a PSU fault.
LED on rear of PSU comes on, I can't hear a fan run, and goes of again after a couple of seconds.
I obtained another PSU, but that does exactly the same on the LED and no change to the system.
I have disconnected everything from the motherboard with the exception of the CPU as I have no thermal paste to hand at the moment. No change.
CMOS battery exchanged.
So just the bare board with the two power connectors attached, and still no power.
I even tried a new power switch as that has tripped me up in the past.
To me at this point, it has to be the motherboard, but everything I read states you should get an LED code in the power switch for a mainboard fault, which I don't have.
Am I missing something here ??
Many thanks,
Andy
JOcean
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June 8th, 2023 08:00
A good progressive method of diagnosis. If you installed a known good working PSU with no change and connected only the MB. Then tried another power switch and installed a new CMOS battery. You have pretty well limited the problem to either the MB or CPU. Remove all the RAM and try to boot as you should get an error with no RAM (either beeps or diagnostic lights). If you get nothing then probably the MB. Though I have seen a bad CPU cause such a no power problem.
Just curious, if you connect the MB, including the CPU, to the PSU try to boot without a CPU cooler. Now only do this for a few seconds. You should feel the CPU starting to get warm, again don't do this for more than a few seconds. If the CPU does not feel like it is getting warm then for sure the MB or CPU is the cause. This page at Superuser has more information on CPU temps immediately at boot.
redxps630
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June 9th, 2023 07:00
It is not reliable to use diagnostic led code being present or absent to r/o faulty motherboard. The board can be defective enough that its cmos cannot even give any intelligent sign. If two psu (at least one presumably working) cannot being any sign of life to board, the board is bad until proven otherwise.
JOcean
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June 9th, 2023 12:00
I agree with @redxps630 but if the MB detects no RAM and gives a code or beeps it may be possible that the CPU is the cause, and I have seen a bad CPU cause a no power symptom. I also had a strange one lately where the system would not power up at all, absolutely no signs of life. It turned out to be a CMOS problem and pulling the battery for 15 minutes and reinstalling brought the system back to life as if nothing was ever wrong.
Andy 01
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June 13th, 2023 03:00
Just to close this off, thanks for the conformation, yes it was the motherboard.
It was all a very strange situation.
This is actually my HTPC connected to my TV.
Replacement motherboard solved the power issue, but I couldn't get a HDMI signal to the TV anymore.
Very long story short, and a few hours of testing, and what ever happened (power surge possibly) took out the motherboard, the HDMI cable and the HDMI port on the TV !
Only when using a different lead in a different port could I get a signal again.
However, all resolved now, so thanks for those that took the time to reply
JOcean
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June 13th, 2023 18:00
Happy to see you got it all working again and glad we could help out!