KSGER C245 Soldering station PSU 220V only?

[mkbehbeh]

I purchased this soldering station when it was on sale at amazon. It had a slew of one star reviews, but the price was low enough that even if the controller and PSU were toast, the handle tips and stand were worth more than the price. All of the reviews mentioned that the unit was either DOA, or died on the first use. I looked on Aliexpress and the first clue was that KSGER still sold the 220V version of this station, but all of the 110V versions had been discontinued. I figured That there was a problem with the 110V on the power suppply and the controller would be fine.

I am posting everything about the station here, in the case that some of the experts can weigh in on whether there is an easy fix to run the PSU
On 110V or if it’s a lost cause, and what testing that I need to do to determine which is the case.

What I did so far:
I broke in tip separately and added solder

1. Powered up with only controller and no handle (worked)
2. Powered up with controller and handle in station (sleep mode, worked)
3. Lifted handle to heat up to set point of 150C and POOF!
4. Found the PCB mounted fuse was blown (3A) external 5A fuse was OK
5. Shorted the 3A fuse using current meter set on max mode plugged in controller and read 1.8A before blowing 5A fuse
6. Probing around I found that the MOSFET on Q1 was a dead short between S-D and S-G

Removed the MOSFET at Q1 and confirmed the MOSFET is dead. My next step is to see if I can power the controller on the bare board with DC only 1t 18V and see if it works.

Am I on the right track? What else should I check?

Thanks,
Mark

[mkbehbeh]

Here are the components that I could read
Selected Components:
R1 Inrush NTC 5D-11

BD1 Bridge rectifier GBU 808

Q1 MOSFET?? F 20B
FQPF
10N60C

U1 873A
LOUV

U2 Opto isolator FL
817C
F118

D1 MB
3020
ON (semi)
NE

Q2 431 voltage ref 431

[stj]

maybe the output diode is breaking down under load