IP35 PRO Start-up Problem

[Terence]

I've just built a new PC with all-new components:

abit IP35 PRO motherboard
Antec Neo HE 500 power supply
Intel Core2 Duo E6850
2GB Corsair TWIN2X2048-6400C4 memory
GeForce 7900 GS OC PCI Express graphics card

When I try to start with this configuration I get the dreaded 8.2. POST code (Enable ATX power supply). The red 3VSB LED is lit, but not the green VCC LED. I cleared CMOS, but it didn't make any difference.

Suspecting the PS I switched it for a known-to-be-good 480W PS (an Antec True 480) from a working computer. This time when I try to start the PC, all the fans (case, CPU, graphics card) turn on briefly and then stop and POST code 9.9. is displayed (Complete power off sequence). After about four seconds the fans cycle on and then off again. This repeats until I turn off the power.

I tried an older 350W PS. This time the system boots and I can get into the BIOS. I set the memory voltage to 2.1v (recommended for the Corsair memory) from the default 1.8v just in case this was the problem. The system boots every time with this PS.

I changed back to the 480W PS, but the problem is still there - the fans cycle and I get the 9.9. POST code.

I tried the 500W Antec NEO HE PS one more time, but that just gets me back to the 8.2. POST code.

I am going to return for an axchange the 500W Antec NEO HE power supply, but is this the problem?

Could it be the motherboard?

Why does an older, lower power PS (not an Antec) cause it to work OK?

I hope someone out there can help since my fingers are getting sore from fiddling with all those connectors.

[BUFF]

Imo it's unlikely to be the mobo.
There has been a lot of change in the way that PSUs are designed & built over the last few years.
Unfortunately along with that has come more incompatabilities etc. (Seasonic who I believe build the Neo have preiously had a lot of problems with Asus & DFI mobos) & whilst there are definitely a lot of people having no problems with Seasonic made PSUs & IP35s there do appear to be some having problems.

[Dreaming]

I can guarantee the Antec NEO HE 550 is compatible with the IP35 Pro. I'm using that set up.

[SteveCliff]

Hmmm ... when I had my IP35 (not the pro version though ...) I had this. I 'cured' it by resetting the CMOS about 4 times in a row (I.E. jumper on, wait a few seconds, jumper off, re-boot, repeat ...)

Might have been complete fluke of course, but it suddenly started working and all has been fine (other than it's trick of powering off, then on again whenever you first boot it up in the morning. Cross fingers a new BIOS update will sort this out though!)

Be interesting if anyone knows what the problem actually is though, even if this repeated CMOS clear sorts you out as well?

Good luck!

[Terence]

I've just tried another brand-new Neo HE 500 power supply. This time I don't get the 8.2. POST code and the fans go through the power on/off cycle, so the problem is still there. I tried again with that old 350W PS but that now exhibits the same problem so now I can't even get into the BIOS.

I tried one more thing: I disconnected the 8-pin +12V power connector from the motherboard. Now the fans run for about 9 or 10 seconds before stopping. A POST code of 8.7. (Check CPU core voltage) is displayed. I suppose this code is to be expected with no +12V power to the CPU.

I'll try the multiple CMOS resets next.

So now I've tried 4 power supplies, so I'm leaning more towards a motherboard problem.

Thanks for all the help, guys.

[BUFF]

Originally Posted by Terence

I tried one more thing: I disconnected the 8-pin +12V power connector from the motherboard. Now the fans run for about 9 or 10 seconds before stopping. A POST code of 8.7. (Check CPU core voltage) is displayed. I suppose this code is to be expected with no +12V power to the CPU.

absolutely & that also shows that the mobo appears to be alive & working which is why I said earlier that I didn't think that it was a mobo problem.

[Terence]

I followed Steve Cliff's advice. I turned off the power at the PS, reset the CMOS using the back panel switch, waited for about ten seconds and powered up again. I did this once (not the four times he suggested). Now it works. Go figure!

Incidentally, I had reset the CMOS prior to attempting the first boot-up (this is recommended by abit in the Troubleshooting section of the User's Manual)

Thanks Steve!

[SteveCliff]

Glad you're up and going now Terence! No idea why clearing the CMOS sorts it out though - and even more puzzling, why you have to potentially do it more than once???

Anybody know if you're supposed to leave the jumper in place for a particular length of time to do the job "properly" ?

[gilgamesh]

Originally Posted by SteveCliff

Glad you're up and going now Terence! No idea why clearing the CMOS sorts it out though - and even more puzzling, why you have to potentially do it more than once???

Anybody know if you're supposed to leave the jumper in place for a particular length of time to do the job "properly" ?

Yes I have heard of this case before. Even with the jumper changed it ni some cases takes a while to the CMOS chip to discharge fully.

Sorry folks about my absence this last week, had to stay at home as my baby ahd the chicken pox.

Glad to be back


gilgamesh