|reply to daveinpoway |
Re: Supermicro motherboard beeping
Do you have another power supply to test with? Could be a bum PS
It could be the power supply (yes, I have a few spares sitting around), but the BIOS Hardware Monitor shows that all of the voltages are fine.
I suppose it is worth spending a little time to swap out the PS.
OK, I tried another power supply- still beeping while I am in the BIOS setup.
Unplugged the floppy drive- still beeps.
Unplugged the optical drive- still beeps.
Running out of options here.
It turns out that the beeping stops if I use a fan setting other than the 4-pin, Super Quiet one. Not sure why- both the CPU and the rear case fan show an RPM reading in the BIOS hardware monitor, so it would appear that the tachometer circuitry built into the fans is OK and the tachometer outputs can be read by the motherboard.
Unfortunately, the system is not domesticated (meaning quiet enough to use in my bedroom 24/7/365) unless I use the fan setting which causes the problem. Since I used the "problem" setting for over a year with no beeps, something (no idea what) has obviously changed.
I tried calling Supermicro support- all I got was a recorded message that they are closed for the holiday.
So, I resorted to drastic measures- I pulled the rear case fan tachometer wire out of the connector (only the Power, Ground and PWM Control wires are hooked up). This way, the motherboard does not even know that a case fan is installed. Not a permanent solution, but it should hold up for a few days until the support department opens up again.
I finally got ahold of the Supermicro support people. The man I talked with said that the beeps indicate local overheating, but he had no explanation as to why unplugging the rear case fan (which, if anything, would cause the internal case temperatures to rise even higher) will make the beeping stop. He also said that I should add a front case fan, but, again, he could not explain why the system has been able to operate for over a year with no front fan without beeping. Since the system is basically loafing (the AC power consumption is only about 40W), adding a front fan would not seem to be needed. As it is, the air blowing out from the rear of the case is barely warmer than the room temperature.
He did have a good suggestion that I should try plugging the rear case fan into a different connector on the motherboard (there are 2 unused fan connectors). If/when the beeping starts again, I will try that. It will help determine whether there is an electronic problem related to the connector I have been using.