Restarted machine, Error code: 8.7 (IP35 Pro)

Teaf · 9 Jul 2008 at 22:39

[EDIT]: All fixed, PSU was dodgy, replacement works fine.

System:

Q6600
Abit IP35 Pro
HD4850 512MB
4GB Geil ULL DDR2 6400
Corsair HX520W

I was adjusting some fans in my computer for noise control when I decided to move a couple of them around so I shut down, unplugged the PSU cable and started work. Finished work, then plugged everything back in and turned it on. All I get is a split second of power, then it shuts off and the LED code display says "8.7" which from the manual means:

"Check CPU core voltage"

"Uh oh" was pretty much my words at that point :/ Fiddled for ages, stripped it down to barebones, reset CMOS, all the normal stuff to do but still just a split second of power and "8.7" on the counter.

Grabbed dads machine from the other room and stripped out the PSU as I targetted that first for being the problem since due to the error message, it's either CPU or PSU I'd say. Unlikely to be CPU so probably PSU. Unplugged my Corsair, and used my dads with is some low profile Coolermaster 460W thing. Plugged in the 24 pin motherboard and 4 pin 12v ATX and tried. I got the follow codes:

8.3 - "ATX power supply ready"
8.4 - "DDR voltage ready"
8.7 - "Check CPU core voltage"
8.8 - "CPU core voltage ready"
8.D - "VDDA 2.5v voltage ready"
9.9 - "Complete power off sequence"

Much futher than the Corsair, but I cycled through all of those constantly forever. Forcefully turned machine off at the switched and decided to plug more stuff in as all I had in was my 24 pin and 4 pin motheboard power plugs. Plugged in PCI-E for graphics, sata for hard drive and then DVD-Rom drive. Got the same cycle so I reset the CMOS and tried again and it booted up straight away. It stopped at "7" something, maybe "7D" so I checked the screen and it had booted up and said "Checksum failure" - most likely due to reseting the CMOS.

Just in case switching PSU's had gave it some life, I switched back to the Corsair and all I got was the stupid "8.7" code again and only a split second of power.

What would you suggest? PSU bad or something else?

Thanks in advance for any help!

dan653 · 9 Jul 2008 at 23:01

flibby said:
I was adjusting some fans in my computer for noise control when I decided to move a couple of them around so I shut down, unplugged the PSU cable and started work. Finished work, then plugged everything back in and turned it on.

from that i'd say the ram, swap it out or try individual dimms

always leave it plugged into the mains (but turned off) when fiddling around inside then at least it is properly grounded

Teaf · 9 Jul 2008 at 23:46

dan653 said:
from that i'd say the ram, swap it out or try individual dimms

always leave it plugged into the mains (but turned off) when fiddling around inside then at least it is properly grounded

Normally I do when touching hardware so I'm grounded, but in this case I was working only with molex connector fans so wasn't touching any PCB's or hardware.

On topic however I decided to try my Corsair on my dads machine again, mostly just out of frustration. His only takes a 4pin 12v motherboard instead of a 8pin like my IP35 Pro. Plugged it all in to his machine, started up, got nothing just a flicker of power. Thought "must definitely be the PSU", flicked on/off switch on the back of the PSU again, tried it again and it boots up perfectly fine!!! So I thinking at this point that the 8pin motherboard connector might be knackered and only the 4pin works - since my dads machine takes the 4pin and the 8.7 bios led error says "CPU Voltage" and that's what the 12v rail is for.

Back out comes my main machine to test the PSU again (sigh, 11:30PM and still working) plugged in the 8pin just to test and low and behold - PC boots up like nothing was ever wrong. Hooked everything back up, start PC, voila - all sorted.

I have no idea what went wrong - I can't understand why the PSU would just crap out on me, then start working an hour later and it seems solid so far. Couple of 3dMark loops, 10 mins of Orthos and perfect.

Although the problem is now (seemingly) fixed, can anyone possibly shed some light on this as it has me totally confused :confused:

Cheers!

Puppetmaster · 10 Jul 2008 at 00:13

flibby said:
Snip

I cant offer any help with your problem, but dont you just love it when a pc breaks for some reason. After much hassle you still cant it to work. Leave it for a bit come back and it works first time lol.

Teaf · 10 Jul 2008 at 13:48

Seems to have happened again today, had machine on overnight and woke up this morning and decided to turn it off to clear any used RAM as I was going to play a game. Turned the machine off, turned it back on and nothing but a split second of power and the 8.7 error code again. Tested the PSU immediately in my dads computer and it's doing the same there.

I recently did a mod to my graphics card's molex connector so I can run it at 5v instead of 12v, wonder if i've knackered that up and it's shorting the PSU out and won't let it turn back on for a few hours. Although my computer has been booting with it plugged in...

1. Is it plausable that a botched molex mod could short the PSU out not letting it turn back on for 2 hours?
2. Should I send the PSU back for RMA? I'm worried that they are going to get it and test it, i'll work, and they'll charge me and send it back.

Cheers

dan653 · 10 Jul 2008 at 13:53

flibby said:
Normally I do when touching hardware so I'm grounded, but in this case I was working only with molex connector fans so wasn't touching any PCB's or hardware.

figured you probably knew that when i noticed your post count

flibby said:
I have no idea what went wrong - I can't understand why the PSU would just crap out on me, then start working an hour later and it seems solid so far. Couple of 3dMark loops, 10 mins of Orthos and perfect.

sounds like one or more of the capacitors in the psu or on the mobo hadn't succifient charge at the moment of powering on, my guess is that one or more are starting to degrade, nothing to worry about really unless your seriously pushing your machine, although come to think of it 520watt is a little underpowered for what your running, that 48xx could be what just pushed it to the edge, just not over it (says me with a 430

)

If it happens again just leave it plugged in for while (couple of minutes, psu switched on) before powering on, this should allow the capacitors to reach their full charge to allow it to boot

Teaf · 10 Jul 2008 at 14:04

dan653 said:
sounds like one or more of the capacitors in the psu or on the mobo hadn't succifient charge at the moment of powering on, my guess is that one or more are starting to degrade, nothing to worry about really unless your seriously pushing your machine, although come to think of it 520watt is a little underpowered for what your running, that 48xx could be what just pushed it to the edge, just not over it (says me with a 430)

Hmm, that could be a possibility but it's the same problem with 2 completely different machines. Both just get a split second of power then nothing.

dan653 · 10 Jul 2008 at 14:05

flibby said:
I recently did a mod to my graphics card's molex connector so I can run it at 5v instead of 12v, wonder if i've knackered that up and it's shorting the PSU out and won't let it turn back on for a few hours. Although my computer has been booting with it plugged in...

dont suppose you could elaborate on this; what its aims are and what kind of connector (no of pins & arrangement)?

1. possible i guess but depends on the above
2. a refund or rma replacement which could then be sold on wouldnt be the worst thing your due a psu upgrade

Teaf · 10 Jul 2008 at 15:19

dan653 said:
dont suppose you could elaborate on this; what its aims are and what kind of connector (no of pins & arrangement)?

Sure...

The aftermarket cooler of my 4850 is a Thermaltake DuOrb. It has a molex connector for power, rather than a standard 3/4 pin fan header type. It runs at 12v all the time, so I cut open the molex connector so I could re-arrange the pins of the molex so they run at 5v instead of 12v.

These are not my screenshots, but it shows the same procedure as I did:

http://img214.imageshack.us/img214/3118/26645446zy8.jpg
http://img214.imageshack.us/img214/9201/82310354au4.jpg
http://img337.imageshack.us/img337/343/34174483rp1.jpg

Thanks for your replies also