Hi all,

Have a Compaq Presario sr1360uk which has a green LED on the back of the PSU. After removing and cleaning the CPU fan and top of the heat sink and putting it back together, the Green LED flashes and the PC will not respond to the power button on the front of the unit. After checking Compaqs' sight, I removed all components from the PSU and replaced them one by one to issolate the problem. I get a flashing green LED only when the 12 pin PSU cable is connected to the mobo. I get a constant green LED when all of the other cables are connected, including the 4 pin 12v mobo power cable. I have completed the "with the power cable disconnected hold the power switch in for 5 seconds" procedure to clear any static build up.
Can anyone suggest what the problem is here? Do we think its a PSU issue or something more serious with mobo for example? Any held grately apreciated.

I am not really sure what you did. I can tell you that there are no parts in a PSU that are replaceable/ serviceable by a user. With that said, I suspect that you have a PSU problem.
You also mentioned that the power on switch doesnt work. I suspect that you knocked a cable loose. There is a 2 wire coming from the switch to the Mobo. See if it is intact. Meanwhile I will see if I can find a manual on your unit.

Do you have another PSU unit you can test with?

Hi 123Runner, thanks for your reply.

I have checked that all connections are firmly connected. As for the power switch not working, I think this may be a safty feature of the PSU, but this is speculation. I take your point about it being potentialy a PSU problem but I am unable to use another PSU to test the system (my other unit has a 20 pin main connector and the faulty system has a 24pin connecor) and am loathed to buy a new one only to find that the PSU is not the problem.

123Runner,

managed to put an ATX 2.0 PSU onto the unit and it fires up fine. I guess your first instinct was correct. Unless you can advise otherwise, I will replace the PSU. Thanks again for your help.