Hello all! I'm new to this forum, please excuse me if the question has already been answered.
I recently acquired a pair of 22RH532, never restored. One of them works like a charm, however the mids/highs of the second one dont work, only the bass and (thankfully) the MFB section do. Using the schematics I have some clues about the issue, but my level in electronics is pretty limited, and I wanted your opinion before trying anything.
The fuse (VL409) of the corresponding two power ramps (the +5/31V and the +4/57V) is dead. I suspect one of the transistors (TS439-443) is to blame. I tried to switch the boards of the two boxes, and the mids/highs speakers work just fine with the other board. I would start by replacing the fuse to check if the power rails output the correct voltage, but I dont want to damage the circuit down the line if they're faulty.
How can I investigate the problem any further? What component are the most likely to be the problem? What tests should I conduct?
Thank you in advance for your help.