I got lucky and found the schematics....

Good day.
I'm currently on a vacation and a friend from the camp site asked me to check why his camper power supply does not charge the batteries when hooked to the mains.
The PSU is cramer and from what I've found the same mainboard is used in both cbc-b7 and bcc-b7. The control module/interface panel is Cramer D-5750.
So what I've found so far - the transformer seems to be working fine and the board has no visually damaged components. I tested most of the diodes and transistors with a multimeter (the only tool I got here) and they read fine.
The two thyristors have been...

Probably a stupid question, but have you checked the tweeter and the woofer? Are they shorted?

Unfortunately I can not find any documentation about the fan. The tacho-control wires is a guess based on other papst fans, but again - no real documentation about the pinout or how to connect and use the extra wires.
Just checked aliexpr. and found this https://www.aliexpress.com/item/33023396847.html .. I guess at the price of a decent mosfet, it makes all further interventions on the existing power supply pointless....

The cap between pins 1 and 2 should be 0.1uF (104). Haven't actually measured it.

With the 555 supply connected, the transformer outputs between 21Vac on max fan speed and 23Vac on min fan speed.

I'm attaching a photo of the pot pinout and connector (the red wire goes in the middle).


...

Oh, come on, everyone can repair with schematics and easily obtainable parts .
I will play around with the scope and see what is going on on the mosfet.

P.S. The exact unit model is QTX FH-1500.. I couldn't find any schematics.
The fan is PAPST 959 5414 200, it has 4 wires, but only the power ones are used. Couldn't find datasheet about it as well. I guess the extra wires are tacho and probably some kind of control signal?...

This is how I got the unit - board with burnt marks, lifted traces under the mosfet and dried thermal paste, the fan is the original one. The only thing I did was to test the mosfet and fix as much as possible its traces. I have no idea what has been the original mosfet.
By the way, still haven't tested the board on its original transformer, and I'm not really sure what's the original ACV. The 24V is guess based on the fan label.
The unit is a smoke-fog machine and the fan is used to dilute and blow away the smoke....

Thank you for the replies!
I will start looking for a more suitable mosfet. Any ideas about easily obtainable ones?...

Good day.
I have an AC/DC -> DC PWM (rectifier + 555 buck converter) power supply with MDF11n60, which is getting very hot.
The input is AC from a transformer and the output powers a 24v dc fan. The power supply is used to regulate the speed of the fan.
After several runs on the bench power supply I noticed that the mosfet is reaching 80+C*. The mosfet reads fine on component tester, the thermal paste is changed, the fan is cleaned and with freshly oiled bearings.
When powered directly from the bench psu, the fan takes ~0.7A on 12V. The current consumption is similar...

Good day.

I'm posting this to help other people.

If you have a Vigor AP with some kind of a software issue or just with an unknown admin password and disabled reset button, here is how you can flash a fresh firmware.

Download the firmware from the vigor's website and extract it somewhere.
Download TFTPD64 or other tftp client with file push.
Connect to the unit with an ethernet cable and set your client IP address to 192.168.1.10 (just not .1 or .2).
Start TFTPD64, go to tftp client tab. Select the server interface with the above IP and...