K9MM-V, fans not running

I have a K9MM-V I bought several months ago. I held off bulding it because I
didn't need it at the time, got distracted - plus the pad of transfer paste
on the big Thermaltake R1 TR2 had shards of the broken plastic 'protecter'
broken in shipping so it needed to be cleaned off and the Arctic Silver
reapplied.

It's a basic build, a Athon 3500, Thermaltake, memory and K9MM so far. Thing
is, when I started it up, neither the CPU and case fan ran. I'm thinking
two possibilities. Either there is a temperature point it's supposed to
reach before the fans run, possible since it's newer than what I've built
before (I believe in staying behind the curve, mainly for cost) but I'm
thinking damage might result while I look for temp. settings in the BIOS.
The other thought is, well, I'm using this 500W Ultra XConnect PSU I bought
at the time, mainly for the ropey PS cables. The mobo's main is a 20 pin
from the Ultra, 24 on the MSI K9MM. Research online said it didn't matter
unless you were using high power like dual SLI's. But I might be skipping
power to things like the fans if those four pins are open. I can buy a 20 to
24 pin adapter if that's the problem.
Any input would be appreciated.

 

Make sure the 2x2 ATX12V power connector is installed.

Judging by the proximity of the 2x2 ATX12V connector, to the
only two fan connectors on the motherboard, it could be that
the 12V for the fan comes from the ATX12V. The ATX12V also powers
the Vcore regulator for the processor.

Since the manual claims there is fan speed control capability
on the board, for the CPU fan, then there may be a MOSFET
in the path. If it was not for that fact, you could use an
ohmmeter, to check for continuity. But since the MOSFET
is there, I'm not sure what the easiest way would be to verify
the header.

The CPU is protected against overheat. AM2 boards will have
THERMTRIP, just like Intel LGA775 boards do. If the CPU
gets too hot, the motherboard will use PS_ON# to turn off
the power supply. And that removes the 12V flowing to Vcore.
That switching is instantaneous and without warning.

My guess is, you're just missing the 2x2 square connector
right now.

If the board was a refurb, there is a small chance a previous
customer burned out the copper track that feeds +12V to the
fan header. But think positive thoughts, and hope for a
simple explanation... The path feeding the fan is
not typically protected by fuses.

You should also verify the fans are plugged into the header
correctly. The fan header has a plastic tab, while the fan
connector has a groove. The groove and tab go together, and
the fan connector should fit without a struggle. If you
really had to jam it in there, make sure you're putting it
on the right way.

Paul

 

~~~~~~~~~~~~Bad2Worse~~~~~~~~~~
After writing last night, I tried my thought that maybe the fans would start
at an operating temperature. So I started it, got the BIOS splash screen,
went to Hardware Monitor in the BIOS, watched it rise from 22'C to 26, then
decided it wasn't worth it and wait for a reply to the message. This
afternoon after reading the message, I checked the tightness and the proper
orientation of the fan plugs (all good), the 2X2 rail on the motherboard and
unplugging the 2X2 from the Ultra PSU to make sure of the orientation (it
only goes in one way because of the shoehorn). I tried it again and, when I
flipped the rocker switch at the back of the PSU, the fan makes a three
second spin and stops; turning on the main does nothing, not even the BIOS
splash screen. Ideally, I'd have a spare PS to see if that's the problem but
all I have is another ATX 1.0 (with no SATA). I could buy an adapter but I'm
thinking it might be throwing good money after bad.
Whether the mobo was a refurb, I don't know but it's unlikely. I got it from
TigerDirect as part of a CPU/MB combo, both packaged. Ideally, I should have
tried this within a month of getting the shipment but now it's been about
9-10 months.

I like the "I did this!" of a homebuilt (and I've done it before with no
problems) but it might be better now to keep an eye out on Boxing Day when I
go to the city for an off the shelf even though I've got all these parts.

 

You don't need to have the SATA drive connected, to test the system at
the BIOS level.

Seeing the BIOS splash screen is a good sign. A lot of the system has to
work, for that to happen.

I looked in the K9MM-V manual, and "SMART FAN" appears to be on by default.
The threshold temperature is set at 50C. You may not have waited long
enough for the CPU to heat up. If you can get the BIOS splash screen,
continue your testing... Think positive thoughts.

Reduce the threshold temperature for "SMART FAN" in the BIOS, if you want
the fan spinning all the time.

HTH,
Paul