Does not post, just black screen

It seems that i tried most of these, but the strange part is the pc does not beep or come with any error code, can it be corrupt bios chip?

Hi,

Try some simple things first.

Remove the coin cell CMOS battery from the motherboard (power disconnected of course) and then press the power button for a while to drain any residual power from the motherboard. If there are any corrupted settings in BIOS this should "release" them and hopefully restore it back to its' default settings. Reinsert the CMOS battery, plug in the power and see what happens.

Use a DMM's Voltmeter function to check the various power supplies from the PSU to ensure that they are the correct voltage. Don't know your motherboard but usually there is +12VDC, +5VDC +3.3VDC supplied to the motherboard and CPU etc.

Without a schematic of the motherboard you don't know whether the problem is the BIOS or something else not allowing the process to continue to a point where the BIOS software can function. (i.e. perhaps that is why there is no beeps, you haven't got that far into POST. It may not even be starting.

Apologies if you've already done these things.

Just tryied CMOS battery method, with no luck, i also have spare powersupply to swap with no luck,

Notebene i got two of this pc at home both with same symptoms

strange i cant find any comments on the internet of this problem

yes also tried to swap the cpu ith i7 HD cpu and remove the discreed videocard

with no luck

Hi,

Unless you can get a programmed BIOS chip for the motherboard to replace yours (and it still haven't been proved that it is the problem), then without a schematic of the motherboard, it has to be put down to a 'motherboard' problem.

It may have nothing to do with the BIOS.

It may be something to do with the initial power checks on the board that is done, after the power button is pressed, to ensure that the conditions are right for BIOS to even start.

These checks are inbuilt. i.e. voltage levels are detected at various points to ensure that they are correct and the board can function OK for the BIOS to proceed.

There may be no comments because mostly people don't have access to board level information and flowcharts etc as to what happens when you first press the Power button. The fan turning on may be just to allow it to get up to speed so that it can be detected as working by the BIOS for instance, I don't this for sure but it is possible.