Hi Folks,

I appreciate the help with this, as I know there have been several threads, which I have been reading through.

Have someone who reportedly fed 240V to this unit.

MOV1 was blown up, and I've replaced it. Interestingly, the bridge rectifier is kicking out around 50V AC, and 110V DC.

I'm not seeing any output from the SMPS (T2), and understand we should be seeing ~12V ?

 

If it is a N.A. unit, it will be designed for 120vac.
The rectifier out is not capacitor smoothed, so you will get an AC reading as well as DC.
Yes the SMPS should be around 12vdc, but is very sensitive to spikes etc, the IC usually fails.
.

 

@MaxHeadRoom Thank you. Am I correct in that the outer two pins on T2 (towards the left CAP) are the LV output? From what I can see, edge side with the diode is LV+ and inner board side being LV- ?

Failing output, would 12V applied here (the SMPS outputs appear shorted, so I would remove) be sufficient to troubleshoot the rest of the circuit ?

 

Usually it is STR-G5551 IC is the culprit. D5 is the rectifier.
You can sub in a separate supply if you need to. there are MC2100 with standard transformer supply with bridge and capacitor.
Some had an outboard transformer even.

 

Turns out the SMPS was shorted, so pulled it and am feeding 12V separately. HD2 pin 1/2 show 12V now.

Am not seeing status LD1 lit, and am seeing almost no voltage on input of 78L15 (RG5).

 

If the unit was subjected to 240v (overvoltage) it most likely took out a few components.

 

What should the input voltage in the 78L15 be? I’ll work backwards from there.

 

It is fed through D4, maybe C26 etc, I don't have that part reverse-engineered for this version, if you have the board out, it should not be hard to trace back.