My PC is 2 y.o. One day, after waking from a sleep, it softly rebooted by itself and then...
10 from 11 times I've a problem booting. The symptoms are different and occur randomly:
1) endless reboots before POST beep
2) endless reboots after POST beep
3) POST beep and 9 consecutive beeps
4) no POST beep and no booting up.
In any case there's no image on display.
I've bought a new MB and installed a new CPU cooler.
Also, I've another working PC as reference - I used its parts for crosschecking.
I've tried the following:
1) replacing the RAM with working one
2) replacing the GPU with working one
3) replacing the PSU with working one
4) disconnecting HDs
5) disconnecting all PCI cards
6) disconnecting all front panel switches and LEDs
7) disconnecting front panel USB and audio
8) checked that there's no metallic part to shorten the MB from behind.
The symptoms reoccurred randomly in any of the mentioned tests.
I've tested with multimeter the outlet and the power cord - both supply 225V.
Also tested the PSU when it was:
1. stand-alone (disconnected from PC)
2. on a running PC
3. on a maximum loaded CPU and RAM
Checked the 24 pins and 4 pins ATX connectors. All the wires supply the expected (within voltage tolerance) voltage, except red wires, that supply +5.28V, which is 0.03V above the max. level.
Yep, I've read this guide.
Award's beep codes don't help much, coz there're too much variants of failing boots in my PC. Yesterday, for example, I've got for the first time endless short and fast beeps even before the POST. And afterwards Win7 showed BSOD on boot before the blue "Welcome" screen.
I've updated my BIOS to F9 and changed its battery.
a continious beep on an award bios supposedly means there is a problem with the power supply, system board, or your keyboard. start with the absics and plug in a new keyboard... if it still beeps, than I would check out the system board as you said your psu was working within tolerated specifications. see what you can learn from the make and see if there is something you are missing. (looking for broken peices or loose wires other places on the board is a good place to start.)
I've ran all my checks from the beginning and have found out that I've not tested the RAM properly - hadn't tested separately each stick on each slot.
One of two sticks was problematic and caused all this mess.
Thanks for the help and mental support