57.5 error - not fan or DC cont ????

[DCO57]

Guys,
I thought this would be an easy fan replacement.
An HP 8150 - 57.5 error should be Fan #1 (LPVS exhaust), but noooo.
Then I tried the DC controller, nope.
I checked all fans - all spinning (none squealing or dying).
I'm stumped.

Any thoughts?

Thanks a million

DCO (IBM)

[Big Al]

These fans have a tachometer circuit built in that tells the processor that the fan is turning. Over the years we have seen more and more of these fans with a failing tachometer. The fan is still spinning merrily along but the circuitry thinks the fan has stopped. If you can come up with a known good fan and just plug it in without installing it you may be able to track it down. Firmware in most of these new machines is lacking sophistication and may be reporting the wrong fan? Please let us know what you find. You would need an oscilliscope to see if the tachometer is putting out pulses.

Al

[MichaelTech]

check the fan in the delivery assy. could be just a cable.