computer not posting

Yurihyuga · 5 Aug 2009 at 18:43

Hi I just changed my case and I checked all the connectors. the 24 pin and 8pin connections are in and the PCI-E connectors were in the gfx card the case connectors are in sata and power cables were in.

What happens is when i hit the power switch the machine powers on the fans spin then immediatly powers down. However even though it powers down the power and reset switch on the mobo is still on

Specs:

Q6600
P5Q Deluxe
ATI HD 4890(New and was working fine in previous case)
4GB Corsair XMS2 1066 2x2GB
Corsair 750W HX(New and was working fine in previous case)

Wondering what the problem could be, everything was working fine in the antec 900 before i changed the case, i use anti static matting and always rub my hands over the side case before handling.

The case i put everything in is a silverstone TJ09.

Bob Wya Jnr · 5 Aug 2009 at 19:49

OP

I did say in another thread that it's worth getting a PCI PC Analyser card to diagnose where in the BIOS POST sequence the failure is occuring. As long as there is still power to the MB PCI slots you will be able to read the exact code where the MB freezes up. They are only like <10.00GBP on the bay and really handy to have around in case of problems! :cool:

Otherwise it's just a case of methodical testing of the components. Strip it down to just the CPU and then gradually add in the RAM and then the GPU. You should get BIOS error beeps but the MB powered fans should keep going. Make sure the RAM is seated properly and that the GPU PCIe power connectors are snug. Got anything you could substitute on the board (like an el-cheapo PCIe GPU which doesn't need extra PCIe power connectors)?

Bob

Yurihyuga · 5 Aug 2009 at 20:04

as soon as i get a chance ill start taking components out. Only problem is I don't get any beeps, the case does not have a speaker and I dont think the mobo has one either or it has never worked.

Theres a buzzer icon on mobo with 2 solder points showing + and - so guessing maybe i have to solder one on.

What I do have is spare 667 mhz ram a GTX260 and an e8400 in another comp so i can switch them over and see if it boots if it does ill then do trial and error to see what causes the shut down from the normal setup.

I just hope its not the mobo... considering theres a power and reset light on the mobo, think that could possibly be the problem?

Bob Wya Jnr · 5 Aug 2009 at 22:19

Yurihyuga said:
Theres a buzzer icon on mobo with 2 solder points showing + and - so guessing maybe i have to solder one on.

'old on a minute 'ere... You are guessing whether your MB has a speaker connector or not?? At this stage you should know all 150 pages of the MB manual off by heart!! :rolleyes:

Seriously though RTFM - that is your first port of call not a forum!!

A MB worth more than 20.00 GBP will definitely have either a speaker header or an inbuilt speaker for sure!!

Diagnosing this fault will be a whole lot easier with a working speaker. By starting the board stripped down (even the CPU can go) you'll find the point where the board stays powered up and just beeps at you to indicate that a component is missing. Then you can add stuff back one by one to (hopefully) find the cause of the fault (theoretically).

Yurihyuga said:
I just hope its not the mobo... considering theres a power and reset light on the mobo, think that could possibly be the problem?

The motherboard should power up with nothing but the PSU connectors plugged in and beep at you! If not then there is a problem with the MB itself...
My flatmate has a cheap case that has a bouncing power or reset switch. This did cause a problem where the machine appeared to be crashing frequently and restarting... But generally the machine will POST and may even startup fully (boot to an OS) before rebooting after a random interval! Looked initially like a soft overclock crash...

For some reason I thought of this as a potential issue and just by disconnecting the MB headers for the case leads the problem went away!

Bob

Yurihyuga · 6 Aug 2009 at 09:22

ok done lots of reading on my board. The P5Q Deluxe apparantly loads came with a faulty speaker(apparently) theres 2 4 pin connectors, one 4 pin was for the speaker and even with it in, theres no beep since July 2008 when I bought it.

Might have to look into buying the PCI Diagnostic card with no beep a code would probably have to be sufficient.

However when I get home from work im going to take all the parts out and just connect the power connectors and see if the power stays on.

I did change the ram just stuck a standard 667mhz in single channel and gfx card yesterday and hooked it up to a different power supply it actually stayed on longer so probably stayed on long enough for failed post test and then shut down. Not long enough to get a display though :/ might have helped.

I am thinking its a multiple fault either the ram and gfx card caused the system to shut down almost immediatly or even the PSU. It was late last night and I was too tired to start unscrewing the bracket for my cooler and I should also be getting my TRUE today so gonna change the CPU and see if it boots if not then time for the good old fashioned part by part till it boots and shuts down quick the last part i put in = the culprit.

Kinda wish I RMA'ed that board for the speaker but I couldn't be assed as it worked and since it posted fine, didn't need a beep to tell me that.

mp260767 · 6 Aug 2009 at 11:30

if its since moving case are all the mobo stands in the right place and screwed down properly ?

Yurihyuga · 6 Aug 2009 at 11:50

the motherboard is firm in place, some sections loose because some of the holes won't screw in, but to get the mobo out would literally require you ripping it out. However it was the same with the antec 900 as well weird screw holes.

Bob Wya Jnr · 6 Aug 2009 at 12:04

Yurihyuga said:
However it was the same with the antec 900 as well weird screw holes.

Yeh I had that problem with the Antec 900. Had to use some other standoffs in place of the supplied ones as Antec supplied standoffs that were the wrong threading size for their own case!! :mad:

Wouldn't worry about the motherboard being screwing down 100%. Your main concern should be 33Mhz-266Mhz connections!!

Bob

Yurihyuga · 6 Aug 2009 at 19:55

making some progress, the PSU is faulty, need to RMA that.

Now what happens is when i put my other PSU on, All fans come on at full speed and no display BUT NO POWER DOWN!!! yes!! at least some progress, thinking gfx card is also faulty. I am taking a break from the comp as i been at it since 3pm.

Let me know what you guys think, please.

Yurihyuga · 6 Aug 2009 at 21:06

got to the problem. It was the motherboard, I had my friend bring round his backup comp he had lying around with the good old reliable P35 Board. Put everything in, including the PSU i thought was faulty and it booted fine.

I have a dell comp upstairs which has an x38 mobo and I put in a corsair 650 TX just gonna throw in the parts in there and put the e8400 in it and just run 3ghz stock(not that I have a choice with dell, no overclocking) and my 4890.

For games it will be good enough, wont get the uber fps when overclocking to near 4ghz but it should be more than playable.

I was planning on some time early next year upgrade to core i5/i7, this just gives me reason to go for it whenever I am ready and can cough up the pounds.

I dont really wanna throw down 100 pounds on a decent 775 Mobo now.

When i switched cases I must have borked my mobo somehow, thought I heard a shock, and im usually very careful.

Bob Wya Jnr · 6 Aug 2009 at 22:13

Yurihyuga said:
When i switched cases I must have borked my mobo somehow, thought I heard a shock, and im usually very careful.

Yeh I tend to use antistatic gloves when I'm doing that kind of thing (uber cautious

) - for the small outlay it's worth the extra peace of mind!

Anyway glad you've got the problem pinned down - even if it is an expensive fault!! :cool:

Bob