Intel 815EEA on/off problem

[Fred176]

My computer sometimes beeps 3 times (in this motherboard it means first 64K memory is possibly bad). However, I 've checked the memory and it's ok. I took the whole computer apart and tested the on/off switch and it goes on momentarily as it should and then goes back to infinite resistance. I also took the memory chips out and switched them and put them back in real good and I cleaned some ugly dust off one of them.

Now the computer boots fine without the 3 beeps, however, it goes on the moment I plug it in, which isn't what I want. I suspect that this behavior was also what it did before I took the computer apart (at least the last time I tried the computer). So what I have is the 3 beeps is gone (which is nice since the computer works now and boots to the OS fine) but I have a power on/off problem. I have to plug/unplug which isn't nice. I don't think the switch is stuck. I'm just looking for some odds on this?
1) Switch problem - doubt it.
2) Some internal latch that detects switch on/off. My motherboard is one of those hold for 4 seconds to turn off types. They have a lot of features nowadays with latch chips - sleep, hibernation ,etc.. I'm fairly sure that my switch is the momentary click on/off, not the old AT type since they actually go in, then come back out the 2nd push. This is the momentary-click type.
So is this an electronics problem? I guess it's hard to tell. I need to check the bios codes but I doubt the bios would care how I turn the computer on - by switch or by cord.
I doubt I miswired the computer but I guess I'll check that the wiring is ok.
Any ideas appreciated but it's ok to wait until I check the wiring again. I doubt it's that.
Thanks.

 

[Fred176]

Here's some info from the D815EEA motherboard manual:
2.8.3.3.5 Power Switch Connector
Pins 6 and 8 can be connected to a front panel momentary-contact power switch. The
switch must pull the SW_ON# to ground for at least 50 ms to signal the power supply
to turn on or off. (The time requirement is due to internal debounce circuitry on
the D815EEA board.) At least two seconds must pass before the power supply will
recognize another on/off signal.
Maybe this will help.

My computer sometimes beeps 3 times (in this motherboard it means first 64K memory is possibly bad). However, I 've checked the memory and it's ok. I took the whole computer apart and tested the on/off switch and it goes on momentarily as it should and then goes back to infinite resistance. I also took the memory chips out and switched them and put them back in real good and I cleaned some ugly dust off one of them.

Now the computer boots fine without the 3 beeps, however, it goes on the moment I plug it in, which isn't what I want. I suspect that this behavior was also what it did before I took the computer apart (at least the last time I tried the computer). So what I have is the 3 beeps is gone (which is nice since the computer works now and boots to the OS fine) but I have a power on/off problem. I have to plug/unplug which isn't nice. I don't think the switch is stuck. I'm just looking for some odds on this?
1) Switch problem - doubt it.
2) Some internal latch that detects switch on/off. My motherboard is one of those hold for 4 seconds to turn off types. They have a lot of features nowadays with latch chips - sleep, hibernation ,etc.. I'm fairly sure that my switch is the momentary click on/off, not the old AT type since they actually go in, then come back out the 2nd push. This is the momentary-click type.
So is this an electronics problem? I guess it's hard to tell. I need to check the bios codes but I doubt the bios would care how I turn the computer on - by switch or by cord.
I doubt I miswired the computer but I guess I'll check that the wiring is ok.
Any ideas appreciated but it's ok to wait until I check the wiring again. I doubt it's that.
Thanks.

 

[Fred176]

I guess the next step is to remove the power switch wire at the motherboard but I have a feeling this had absolutely nothing to do with it. But if it DOES, then it's a bad switch - one with too finite an off resistance. I'll try that next.

 

[Fred176]

I tried this, no effect. Computer turns on even with on/off wires disconnected.

 

[Fred176]

I think I might have stumbled across what the problem is. My BIOS has a default state of restoring the power to what it was before (Last State) as the default. Apparently, if there is a power failure, it powers back on without a switch depress. It is a "server-type" of motherboard. Wow, it might be that I just need to tweak that BIOS flag to something different so it doesn't keep going on or else at least reset that BIOS behavior. I'll try that after some dinner, not before, that would be doing too much in one day.

 

[Fred176]

Wow, I just changed the BIOS setting from Last State to Off. Then I still had to unplug the computer. But when I replugged it in, it stayed in the Off state. Then I turned it back on, booted to the OS, then shutdown, then I hit the power button and it turned off ok. So it WAS the BIOS setting. It was not a hardware problem. I had no idea it was the BIOS all along. So the problem is solved, this thread is either over or available for comments. Hey look, even if you didn't help, you might have something to say.