Heat gun motor pcb ?

[Waterworks178]

I'm repairing a heat gun , I'm an engineer and only know very basic electronics, this tool has a dead fan, from what I read they use 240 v ac put through a heating wire as a resistor to run the 12v fan motor but I see no rectifier on the pcb , can anyone tell me how this pcb works ?

 

[Alec_t]

I see no rectifier on the pcb

Top left of the pic there's a xN4007 diode.

 

[davenn]

but I see no rectifier on the pcb ,

Top left of the pic there's a xN4007 diode.

yes ... but what Alex forgot to mention is that it's a half wave rectifier
nasty way to do it, but must have worked well enough

 

[Bluejets]

Capacitor in series with the motor suggests it to be the voltage drop element.
Once again, crude but works so long as motor is completely isolated from the outside world.

 

[ivak245]

If it has the heating element in series with the motor/ rectifier, they sometimes have a thermal fuse in there, mounted in or near the element. This cuts power to everything if it blows. Looks like a little silver bullet.

 

[Alec_t]

Capacitor in series with the motor

They're in parallel. So the voltage dropper would be part of the heating element. I'd guess the set-up is as below (ignore the example component values) :-

L1 and L2 are interference-suppressing chokes (those black-sleeved items in your pic).
I haven't haven't shown the small caps connected to the motor terminals.