Hp lj 3390 cooler fan off!

Hi,

Here is an image taken from the service manual which shows, unfortunately with no actual circuit diagram detail, that the fan is directly controlled by the CPU in the Engine Control Unit.

(click on image to enlarge for better viewing).

If there is no supply voltage available to the fan it is either because the CPU is not telling the fan to turn on or that there is a fault in the fan motor drive circuit.

Try the following to see if it may resolve the problem

1. Reset the printer.

Turn off the power by using the power switch on the printer. Switch off the power at the outlet and remove the power cord from the outlet. Wait at least 30 seconds and then, reconnect the power cord to the outlet, switch on the outlet, then turn on the printer's power switch and wait for the printer to initialize.

2. Reseat the DIMM.

Go to p.32 in the service manual. Ensure that the power is off when you do this.

If the above do not resolve the problem you may have to visually inspect the Engine Control board for problems in the fan motor drive circuit area. Most probably if nothing is obvious you will have to trace back the circuit from the fan connector on the board right back to the CPU.

Here is a link to the service manual for the printer.

http://www.lbrty.com/tech/Manuals_HP/339...

Hopefully this is of some help.