HP COMPAQ ELITE 8300 Won't Boot Up

[Josh0018]

The PC was working fine yesterday, suddenly went to turned it on today, it has a blank screen, pc  won't boot and the fan gets loud after a few seconds. 

[savvy2]

real old 8300 , and has real PsU on some

is this the BIG cased PC<?  tower or sff or mini  or?

no product ID told,

#1 failure dead RTC coin cell on most PC and HDD< bad.  The 2 classic bad actors, at 5 years old some.

the 10second, power button push fails and released this is Intel inside magic this, by logic there.

did you hard cold boot it like this.? power cord unplugged, ,1,2,3,4 steps?

I BIOS dead too the Esc key hammered at power on cold booted?

if the RTC coin goes dead BIOS GOES MAD , nuts, crazy due to NVRAM is SCRAMBLED to random 1s and 0s!

The RTC is first things first check on all PCs over 5 years old, me I check them all anytime I see BIOS messup or TIME or DATES go wrong, RTC is that. endless and forever the same. thing, batteries are weak technology unless billionaire Musk makes them. (LOL)

the transistors can last 100 years have 1968 gear here the still runs new, HAM gear and more.

batteries then HDDtest.

learn that and solve most the easy problems of PC.

as test turn on a PC with no USB devices, short on those are show stopper.