Dead PC, PC fans totally deadthat most times means PSU dead, or shorted modules inside PC> (im sure the power switch wire, to the mobo did not fall off) and the green LED on back of PSU is glowing green , (per manual HP ) means AC power side is good.SR1200 series desktop made in fact in the Compaq plant in Texas.2004 newest 2002, oldest.if the coin cell is that old, it is bad. none ever last that long; 14 years to 16year old batteries are no good. but a DMM check will not lie to you. 2.9v min, lower bad.If both fans are dead , the PSU is bad.in some cases, (no pun) we open the casepower off, (ac cord pulled)push power on to discharge all caps in the PC,normally one sees the CPU fan spin for 1 seconded and die. (but that is good PC yours is not)we remove all power wires from the PSU from itto HDD, to CD, drives, and to floppy 4 pin powerwe do that because shorted devices, cause all PSU to shut down. even in 1/2 of second or LESS.by design (ATX spec) this prevents fire, in the case/psu.plug in PC, AC and push power, do fans run now, both must run , not just one fan.power off again, ac line pulled, push power button again, to discharge things,nowThe once all those pig tails from PSU to THINGS are pulled , but not your MAIN 20 pin connector to mobowe do what, we remove ram and test each stick 1 by one.doing same tests, AC line pulled. remove RAM.but 1 stick reseat it, and test for power on again.if you have the original DDR memory sticks test them 1 by 1, each. ok>? they can short too.