System doesn't boot

Whitman · 2 Dec 2010 at 12:32

I bought a Titan Thor system from ocuk in October last year (1 month out of warranty, damn) and last week it switched off while in use and wouldn't come back on. Opening it up I saw that when powered on the drives spin up and the case fans come on, but the CPU fan (Akasa Nero) just jerks but doesn't spin. There's also no output from the graphics card. The CPU fan has a four pin connector but I tried plugging it into a 3 pin connector on the motherboard (Gigabyte EP45-UD3LR) and it did spin but the computer didn't boot as nothing was plugged into the CPU connector on the motherboard.

I'm thinking this sounds like a motherboard issue as the fan does spin when plugged into a 3 pin connector but is there any chance it could be the fan/sensing? I'd rather not have to shell out for a new motherboard if possible but a replacement fan should be pretty cheap.

95thrifles · 2 Dec 2010 at 14:01

Is there any noticable dust that needs cleaning out? Thats first thought with a PC over a year old, if this is first time youve opened it up
Re the boot process, even not being plugged into the CPU fan header it should still boot, youd merely get an error message during boot asking you to press F1 to continue (unless you disabled this feature in BIOS)
Try a clr CMOS firstly, take the battery out of the mobo and leave for 5-10 mins then put back in and try again
Let us know how you get on with that

Whitman · 2 Dec 2010 at 15:24

I've tried pulling the battery, no success after doing that. I've sprayed out any dust, there wasn't a huge amount. I've also disconnected all of the drives leaving just the RAM and graphics card.

Whitman · 4 Dec 2010 at 19:08

Ok, so I found an old PSU and tried using that. Powering on, the CPU fan did spin. I couldn't check if the system was booting as the old PSU doesn't have connectors for the graphics card. Looks like it's a problem with the PSU but wanted to make sure I'm not missing something before I start an RMA with OCZ.

Freddie589 · 4 Dec 2010 at 19:45

did the system make any beeps at all?

Whitman · 4 Dec 2010 at 21:09

It never has made any beeps, it wasn't supplied with an internal speaker. I'll have to see if I've got a spare one.

Update: Found an internal speaker. With the OCZ PSU that's meant to be in the computer, no beeps and I've noticed that the phase LEDs on the motherboard stay on, 2 green, 1 amber, 1 red.

With the old unbranded PSU the speaker kind of clicks a bit and eventually does 1 longish beep and will repeat that until switched off. The phase LEDs also eventually turn off.

Looking in the motherboard manual, repeated long beeps mean that the graphics card isn't inserted properly which, while it is, it doesn't have the extra power connectors plugged in as the old PSU doesn't have the right connectors for it. Looks like it is the PSU.