Predator G3-710 MB won't boot unless I disconnect the ATX lead

Pilky

Hi, Bought this PC a few weeks ago for my son, its worked fine until yesterday when it wouldn't boot, the case fan and graphics fan spin for around 2 seconds then nothing, if I disconnect the ATX lead it powers up the CPU fan and hard drives for a few seconds then the CPU fan stops but the case fans continue.

I have removed CMOS battery and cleared CMOS jumper, held power button for 30 seconds with the power lead connected but its still the same, I have searched around the internet and seen possibly Motherboard, PSU and thermal paste deterioration ?? anyone had a similar problem or know of any issues please

Thanks in advance.

Ian

JackE

>>>Bought this PC a few weeks ago for my son,>>>

Is it new or used? Sounds like the PSU

Pilky

Hi Jack, its second hand, I am picking up a PSU tomorrow, hopefully that will cure it.

Thanks for the reply

billsey

By "ATX lead" which wires are you talking about? I would normally assume that is the 24 pin main power connector, but that connector has the PS_On signal on it, so the power button wouldn't do anything with it disconnected? Do you maybe mean an AUX power connector (Typically 4 pin)? Those are usually designed in to provide more power to PCIe slots. What GPU card is installed? Does it have an external power connection on it?

Pilky

Hi Billsey, its the AUX power connector I was talking about. I have just tried a new PSU and its still doing the same, so I assume the motherboard has gone.

The GPU is a Radeon R9 with no external connection, I have tried taking the GPU out out and booting but still the same, disconnected all drives, same. new thermal grease to the CPU (just in case) and still the same.

Thanks for the reply though.

JackE

With the GPU socket still empty, you might try re-seating the CPU.a few times to help clean its pins. If you get no video response, it's possible the CPU overheated one too many times and died. The G3's i5 & i7 CPUs are pretty cheap these days.

Pilky

Thanks JackE I will give it a try

billsey

If the MB boots with the aux connector disconnected and fails with it connected, it's unlikely to be the CPU. The aux connector is pretty much only used to provide enough power to the PCIe x16 slot for the GPU. Since it fails with the GPU removed we know it's not likely the GPU card itself, so likely the MB has something shorted on those power lines that run from the aux to the PCIe slot. Could be a shorted capacitor or just about any other component...