[Yaesu] very cool FT-990

[Privacy4me2]

Hello John,

The 990 indeed is a cool radio, you probably have the coolest.

The fan is connected to the REG-UNIT, its gets it opwer from this unit, 
there are however two switches that can trun it on. FAN1 and FAN2 connectors 
gor to the PA, and powersupply.

First find out of FAN1 or FAN2 is shorted to ground. If FAN1 makes the fan 
run, the problem is in the PA, it could well be the transistor switching to 
groune or tehermistor/comperator circuit driving the this transistor.
If FAN2 is the connection which is grounded, the problem is in the 
powersupply.

Regards,

Edwin PE1PWF