I recently purchased a pair of ML N 33h mono amps from a friend whose father kept them in storage for several years. I plugged them in for a test yesterday and they seemed to enter standby mode and turn on properly but did not push any power to the speakers. After about 20 seconds one of the amps started to generate a crackling noise from the speaker and emit a puff of smoke. I turned the amps over to discover they were both leaking a dark sludge out of the bottom grill. I took the grill off expecting to see a bloated capacitor but the sludge seemed to be dripping out of some diodes as you can see in the attached pics. The amps are probably overdue for a complete re-cap, has anyone had experience servicing this model?
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I can't really help, but I haven't seen that sort of failure from diodes before.
That doesn't mean it doesn't happen though.
I will say any of the type of epox-rifa caps as circled must be replaced.
The epoxy coating cracks, lets moisture in, cap then fails and smokes/burns.
Lovely pungent smell. eww.
Chances are this is where your smoke came from.
That doesn't mean it doesn't happen though.
I will say any of the type of epox-rifa caps as circled must be replaced.
The epoxy coating cracks, lets moisture in, cap then fails and smokes/burns.
Lovely pungent smell. eww.
Chances are this is where your smoke came from.
Hello, there was a man repairing his No.332 with this black leakage and he said: "was actually a dyna-mat type rubber sound dampener material stuck to the walls of the amp" that melt due to high temperature inside of the amp. Do you know where it came from in your case, please? Do you have it repaired alerady? Please let me/us know. I am very interested. Thank you!
Are you sure that electrolyte has black color? Also strange is that these capacitors are two in front and two in the rear of transformer. The leakage is in the middle.
