FYI - ML370-G3 Fan problem found and solved

[PDP-Fan]

Many ML370-G3 servers failed because of fan problems. Mostly units equipped with redundant fans (6 fans) have failed, while units with 3 fans worked fine.

The problem was the fan speed regulator circuit which has become overloaded, overheated and finally failed. Maybe the cause is a weak design or possibly a aged capacitor that created additional load to the circuit.

The fan regulator transistors are located between PCI slot 3 and 4. There is one pair for the I/O fans and 4 transistors for the CPU fans. The transistors are SMD 8pin devices that look like small ICs.

After changing these transistors and also the capacitor nearby, the fan problem was gone. The transistors had clear signs of overheating and the capacitor too.

So, if you have this problem on a ML370G3 and don't want to spend much money for a new board and you are skilled enough to solder SMD... this is your change to fix it.

[Marinello]

Christian,

do you have any circuit diagram for ML370 G3 ? We still have many of these servers, and the repair costs by HP are astronomical.
Which transistors and capacitors are exactly affected ?
Otherwise, can you contact me about this on cyberpunk@shinternet.ch ?

Thnx,
Robert