The computer does not start, what can be?

Chvalov2015-01-09 01:53:48

Iron

Chvalov, 2015-01-09 01:53:48

I turned off the PC, after two days I turn it on, but it does
not start in any Post and there is no sound
All the coolers work
The indicators on the keyboard do not light up at the moment of turning on, as it was before
The monitor is in standby mode
Only one power diode is lit on the system unit The
mouse indicator is on, Power is supplied to it, but it has always been like this.
What could it be and where to look?

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8 answer(s)

Chvalov, 2015-01-10
@Chvalov

I found the problem, but I don’t know how it can be called
. The problem is that the PSU does not produce a stable current, but with noise (I watched it with an oscilloscope)
And it’s treated simply, I connected the power to the rum or the second hard drive and it starts.
On mat. the board is protected from such noises from the PSU, when another device is connected, the noise is much reduced and the protection does not work (That is, you need to give a little more load to start the PC)
After turning it off, I turned off the power from the rum and two hards, and continued to work.
Most likely the problem lies in the capacitors, since I have had a PSU since I was 13.
But usually such signs appear only when the south bridge dies)
All the actions that are described were done before writing this question, I thought that I would learn something new, but alas.
Thanks everyone for the replies, they'll be helpful

Dimitri, 2015-01-09
@Kvarkas

pull out all the video card, disks, sdrom, memory, leave only the processor and power - try to turn it on - it should start beeping plaintively - add frames, try turning it on again, if it is silent - most likely you can’t determine the malfunction yourself, you need to show it to specialists

Alexander Kamolov, 2015-01-09
@dintsec

Sometimes resetting bios helped (if not in the hardware problem)

O Di, 2015-01-09
@insiki

Unplug the power cord from the system unit, if this cord was inserted into a surge protector, unplug the power cord from the power outlet. Poke on the "Power" button, plug the cords back, try turning it on.
It will not work, do what Dmitry suggested above.

Sergey, 2015-01-09
@Derzaiii

Once there were the same troubles - he was silent like a fish on ice. A simple method helped - I took out everything that comes out and carefully blew / wiped it from dust.

maaGames, 2015-01-09
@maaGames

It happened to me after a partial failure of the motherboard ...
But first, pull out everything that is pulled out, blow it off the dust and put it back one by one, listening to POST.
The motherboard without everything can also be turned on, it should squeak about the absence of a processor, for example. At least it has to squeal somehow. It is advisable to connect the mother to a known good power supply.

mad_DOG, 2015-01-09
@mad_DOG

after the action from the council of Demetrius. if there are no beeps when the devices are turned off, you can still try to check the north bridge [the largest heatsink after the processor one], if it gets warm, then most likely the problem is in it

boOogdan, 2015-01-09
@boOogdan

You may have Windows, be very careful. If so, urgently install Linux or MacOS