A switch problem?

[LugwidVanB]

I have an ongoing problem that will probably get worse over time. I turn on the computer and it appears to have power, the fans are on, but there is no screen, no boot. I have to press the reset switch which then causes it to boot. I have a desktop which doesnââ?¬â?¢t beep at any time.  Is this a hardware problem and how do I fix it? Thanks for your input.

Tom

[Buffalo2102]

It's unlikely to be switch problem IMO.  More likely to be the power supply.  When you first turn on the system, the power demand is very high so the PSU has to supply a surge of power and if it isn't adequate for the demand it probably wont boot.  However, if you then press the reset button, the power surge is much less because the PSU is already supplying power to the mainboard and some other components.

There are several things you can try to prove this -

1. Disconnect all non-essential peripherals (if there are any) before powering on.  Power the monitor separately, instead of from the PC PSU.
2. Check the power rail readings, usually found in a page in the BIOS on most modern motherboards.  There are some free diagnosis applications that will let you see this information from within Windows as well, iirc.
3. Borrow someone else's PSU (ensuring that it is man enough for the job first) to try instead.

Hope this helps.

[LugwidVanB]

Thanks Buffalo, I will check this out and report back. Tom

[LugwidVanB]

I don't know what power rail readings are but in the bios there are these readings for voltage: Vcore 1.36 volts; 3.3v 3.37 volts; 5v 5.08 volts; 12v 11.84 volts.

[Buffalo2102]

Those are the ones.  They all look OK so there doesn't seem to be a fundamental problem with steady voltages supplied by the PSU.

You will still need to test using another PSU if you can as the issue may well be the load on the PSU at startup as I described earlier.