Folks,

The e-machines T5212 I rebuilt for my mom has begun having problems - when started it won't boot. Here are the symptoms:

1. Press the 'on' button on the front of the mini-tower. Button lights blue

2. CPU fan runs at low speed

3. HD shows a little activity, initially, but no sustaining running as usually happens when booting up

4. No audible beeps when booting

5. No signal sent to the screen (just the RGB blocks)

6. No usual ASUS MB screen flashing past...

The PC was rebuilt with an ASUS motherboard and a Seagate HD. The power supply is still OEM, as is the DVD drive.

When the computer runs normally the MB CPU fan starts at a low speed (like 2. above), then speeds to a really high speed (lots of fan noise), then gradually slows down to a very quiet noise. This is due to ASUS MB BIOS having the ability to program the fan speed based on one of a few preset modes. Since my mom is a very light PC power user, her setting is for lightest CPU use, and thus is the quietest. This fan speed/noise sequence does not occur.

Any thoughts? I have not purchased a diagnostic tool yet, though I'm thinking I ought to. Could it have to do with the power supply? I've heard the e-machines OEM PS are really lousy, don't last long, and can cause other system problems. Maybe the HD? It spins a bit, which is clearly better than when the OEM HD crunched to a halt and expired.

??

Any help is very appreciated.

Elia

First a question - did you use thermal paste between the processor and its heat sink when reinstalling it?

Then, suggest following course of action to isolate problem:

Check the power supply with a tester. I have replaced the power supply in almost every eMachine that has come through the door.
Remove and reinstall memory.
Disconnect everything from motherboard except for minimum required memory and video card. The board will P.O.S.T. (Asus screen flashing past) without a hard drive or anything else connected.

If board doesn't P.O.S.T. problem with board or memory although most boards beep or display a light sequence if there is a memory problem. Also check for screws or any loose items between board and case, or in board slots.

Scleros,

When thinking back to when I rebuilt mom's PC I don't recall applying any conduction or thermal paste... so I'm going to have to say 'no, I didn't'. I seem to recall there being paste on the CPU when I took it off the e-machines MB.

Do you think I might have done damage to it?

I have a digitial multi-meter so I could check voltages coming out of the PS... any guides as to what those ought to be?

Thank you for your help/response.

Elia

Some type of thermal interface material has to be applied between the processor and its heatsink for proper heat transfer and cooling. If the original interface material was not replaced or replaced improperly, it is very easy to burn up fast older processors within seconds of powering them on. Modern processors will throttle clock rate or no execute to prevent overheating.

Power supply connector pinouts are pictured at HelpWithPCs.com ( http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm) and listed in the ATX Specification 2.2 (http://www.formfactors.org/developer%5Cspecs%5Catx2_2.pdf) (page 20). Inexpensive power supply testers (examples Antec (http://www.antec.com/Believe_it/product.php?id=MjA3OA==), Coolmax (http://www.coolmaxusa.com/powertester.asp?item=powertester)) are available that simplify the job.

Scleros,

I was away for the week on business, thus the delay in responding. My folks brought the computer to my house this afternoon and I'm going to go through your list in sequence. I'll respond after some testing. Many thanks.

Elia