weird problem with a pent 933 & Tyan 815e mobo

[budz]

I have a old pent 933 pc with a fairly new Tyan 815T mobo I purchased months ago from Newegg.com. I decided to get a new mobo for it since I have spare parts and a extra antec case.

The problem I'm having is when I shut down the pc then want to boot it up again the pc doesn't power up. But if I unplug the power supply cord from the case then reattach it will power up after a period of time. At first I thought it was the new Antec True power 430 watt power supply so I returned and got a True Power 330 since the 430's were out of stock. The same thing is happening even with the new 330 PS. I've checked the BIOS and I had contacted TYAN via email when I first got the mobo. I was told the mobo is a server mobo and in the BIOS I had set the AfterG3 Enable to ENABLE because I notice the pc would start up when I plugged in the power cord to the pc. As I've already stated the pc will not boot up after it's powered off. I press the power on button on the case and the pc doesn't power up. I end up removing the power cord and plugging it back in after a period of time then the pc will power up. Then I get a CMOS error that I have to set the BIOS again.

Here's what the BIOS is set under POWER looks like:
Power management mode [ACPI]
ACPI S3 Support [DISABLED]
Standby Time Out [DISABLED]
Suspend Power Saving Type [S1]
Suspend Time Out [DISABLED]
Power Button Mode [On/Off]
AfterG3 Enable [ENABLED]
Green Pc Monitor Power State [Off]
Video Power Down Mode [SUSPEND]
Hard Disk Power Down Mode [SUSPEND]
Hard Disk Time Out (Minute) [DISABLED]
Display Activity [IGNORE]
Manual Throttle Ratio [50%]
THRM throttle Ratio [50%]
Intruder Sel [SMI]
TCO Logic SMI Enable [DISABLED]
RTC Resume [DISABLED]
AC97 Logic Resume [DISABLED]
USB Controller Resume [DISABLED]
PME Resume [DISABLED]
RI Resume [DISABLED]
SMBUS Resume [DISABLED]

The pc used to work perfectly fine until now. I've also upgraded the BIOS to the latest version. I don't know if it's something in the BIOS in the POWER set up that is wrong or the mobo is defective. And I wonder if the Antec case power wires connectors are dead/defective. If it's the power connectors from the case then I might as well return the 330 PS and pick up a Antec case that comes with a PS. Since the cost of the 330 PS is $73.00 I can get another Antec case w/a PS for the same amount.

I'd appreciate any advice on this problem. Thanks in advance. I would like to make use of this mobo and 933 chip. Although it would be tempting to just purchase a cheap Asus 478 mobo and p4 2.26 processor.

[hellbringer]

check your bios for a power on by keyboard or mouse if u enable that and cann't get the computer to boot with that then its your switch. since u already swapped the psu thats not it, which only leaves the switch or motherboard i guess.

[hellbringer]

oh ive never used that function before but i think it lets u boot your computer when its off by useing either a keyboard or mouse.

it either does that or allows u to turn on the computer that way wwhen in hybernate or softmode or something.

[hellbringer]

few other things you could try is different power cords, im not totaly sure but i think monitor cords will work for a quick little check but i wouldn't use them for long term.

also u could try hotwiring, take the 2 wires going to your power button and cut the plastic off them then take another wire and connect them or hold them together lol you might want to do this just so u can say u hotwired your computer, ive never done this so if your computer blows up sorry

[rallynavvie]

Ooh, ooh!

Does this happen only when you've had the computer off for a while? When you turn it on do the fans spin but the board doesn't boot? Have you tried letting it sit powered on like this for a few minutes and then hitting the reset button?

I'm just kinda curious if this is a Tyan-specific issue. My Tyan 2460 does what I described, like I need to warm it up or something before it'll boot.

[budz]

Ooh, ooh!

Does this happen only when you've had the computer off for a while? When you turn it on do the fans spin but the board doesn't boot? Have you tried letting it sit powered on like this for a few minutes and then hitting the reset button?

I'm just kinda curious if this is a Tyan-specific issue. My Tyan 2460 does what I described, like I need to warm it up or something before it'll boot.

I can shut down the pc then want to boot it up again immediately and it won't power up. The fans don't even spin when I press the power or reset button on the pc. I end up having to clear the CMOS then it boots up immediately when I plug the power cord back into the pc. I'm going to email Tyan tech support to see if they can help me figure this out. Any other comments will be greatly appreciated!

[hellbringer]

couldn't u leave the battery out then the cmos would clear everytime u boot, for a temp fix

[hellbringer]

do u change anysettings after u boot the computer up after clearing cmos?

also after u boot up after clearing cmos, go into bios, then go and click clear changes or use default settings...maybe when your computer boots up it detects some kind of changes and things get changed before u get into bios,

so after u click use defaults, look and see if any options changed or w/e.