New case, now pc doesnt work

OpenToSuggestions · 22 Jul 2008 at 19:50

As title, I bought an antec300, got it home and ordered a p12v cable extender and a 24pin atx extender as psu cables were not long enough.

Anyway, fans spin, with graphics card on max.....nothing shows on screen. Have tried my brothers 480w tagen and have tried the motherboard out the case on the box it came in with just ram,cpu,gfx and ram, and the same happens (with the psu next to it to see if there were any shorts inside the case and to see if the extender cables were faulty).

I know finding the issue is a matter of trying different parts until the problem is solved, but this will be a problem as I do not have a spare core2duo motherboard nor a spare core2duo cpu.

If I unplug the 12v atx cable (the square 4pin one that is completely different to the 24pin atx), the same thing happens, fans spin and no post.

Any ideas? Thanks

Snakedoctor · 22 Jul 2008 at 19:57

So, did it work OK before you removed it from the case? What prompted the new case, was it a faulty PSU? Try resetting CMOS and see if that allows it to boot into BIOS.

OpenToSuggestions · 22 Jul 2008 at 20:46

PSU was fine, it is the 450w one from the sonata2 case. The old case's door snapped off, and was just generally battered and looked a mess.
Just tried CMOS reset (via the jumper and by removing battery for a min) no luck.

I am thinking fubared motherboard or cpu?? I have had problems in the past where the computer gets to the motherboard logo screen and for 1min then says file missing. (LEaving pc for an hour or so and trying again and it worked fine). No idea if this is relevant though...

Corasik · 22 Jul 2008 at 21:05

Memory voltage may have reset to default 1.8V. I assume you have several sticks of ram in there, its possible that 1.9 - 2.0V will be needed for the system to even POST.

Try removing all bar 1 stick of ram from the system. If the first stick doesnt get the system posting, remove it, and try the next stick as each stick will have slightly different tolerances, hopefully one will be stable enough to post, so you can get into bios.

Its extremely unlikely that the CPU is faulty, unless you installed the motherboard without spacers and shorted everything out.

Anyway my bet at this point is ram voltage.

As a long shot, if you cant get it running before you give up for the night, leave the motherboard, with battery removed, and disconnected from the PSU over night, it might recoverer itself by morning. Can use the CMOS clr jumper as well for good measures.

OpenToSuggestions · 22 Jul 2008 at 21:34

mglover070588 said:
If I unplug the 12v atx cable (the square 4pin one that is completely different to the 24pin atx), the same thing happens, fans spin and no post.

Could this have any significance??

I just tried individual ram sticks and no luck.
The cpu has never been overclocked so surely that wont be dead, but I cannot really try another one as the cpu cooler mounting pins are on their last legs and once removed I will have to buy a new cooler.

Althulas · 23 Jul 2008 at 14:48

If none of the above works.

Have you plugged anything into your usb headers? I did this once with and plugged incorrectly. Worth rechecking all your connections just to be sure.

artaxerxes · 23 Jul 2008 at 15:06

Recheck your on switch wiring!
Then recheck again.

Reduce to minimal components, try again.

Check for contact between the backplane and mobo tray.

Rebuild outside the case - you might of been shorting on the case

rjk · 23 Jul 2008 at 15:29

have you got a display on the board?
if not are you getting any beeps form it?

OpenToSuggestions · 23 Jul 2008 at 16:35

Left it overnight, an tired again, no luck (motherboard is no longer in the case). The only hardware in use is psu, ram, cpu, motherboard gfx and power switch. Graphics fan spins at max and does no slow down. The cpu fan spins slowly like it should. There is no been when I connect the speaker. and startup (on the ds3 on regular startup, gfx spins at max, case speaker beeps, gfx fan slows down to silent and system posts).

No usb or pci devices attached, no other case switches or front audio/usb attached or anything. The psu is deffo not at fault. Will try and get my brother to allow me to try my 8800 in his rig, although I highly doubt this is the problem.

EDIT: does a system need ram to just show SOMETHING on the screen?? I know hard drives arent needed

OpenToSuggestions · 23 Jul 2008 at 17:32

Graphics card is not at fault, just tried in brothers rig. Didnt think for a minute it was that but now I know it isnt a problem.

Althulas · 23 Jul 2008 at 22:30

You cpold try the mobo out of the case to rule out any short circuits.

Hodders · 23 Jul 2008 at 22:46

Althulas said:
You cpold try the mobo out of the case to rule out any short circuits.

What he said - this has worked for me in the past.

OpenToSuggestions · 24 Jul 2008 at 00:43

Althulas said:
You cpold try the mobo out of the case to rule out any short circuits.

motherboard is already out the case

Only things I can think of now are dead motherboard and/or dead cpu. Although I suspect dead motherboard.

OpenToSuggestions · 25 Jul 2008 at 19:50

Anyone got any more ideas? Pc still dead

OpenToSuggestions · 27 Jul 2008 at 17:51

Still dead, surely its dead motherboard?

beano · 27 Jul 2008 at 18:15

mglover070588 said:
does a system need ram to just show SOMETHING on the screen?? I know hard drives arent needed

I believe so, but maybe someone a little more knowledgeable can confirm.

OpenToSuggestions · 28 Jul 2008 at 15:23

Any more help

really want to get this issue sorted asap, thanks!

fobose · 28 Jul 2008 at 17:39

Someone above suggested to try one stick of ram, have you tried this yet? Did you try the other stick on its own if the first single stick didn't fix the problem?

OpenToSuggestions · 28 Jul 2008 at 19:11

fobose said:
Someone above suggested to try one stick of ram, have you tried this yet? Did you try the other stick on its own if the first single stick didn't fix the problem?

yea have tried this

both sticks individually.

Ch3m1c4L · 28 Jul 2008 at 19:20

Does sound like a dead mobo. Specially since it does exactly the same without the 4pin connector plugged in. You are using the correct 4 pin and not some other random connecter aren't you?

But I would agree with you that its a dead mobo since its unlikely your using the wrong connector, and i have kille d amobo just by changing the psu before....stupid hardware.