soma89
Well-Known Member
A very cool looking tiny little integrated amp.
Nikko TRM-210
So i got this thing strictly to fix up (there was distortion on one of the channels.)
WHAT I HAVE DONE..
I first recapped the whole thing. One cap was in the wrong way and it blew, damaging a resistor in the process that ive since replaced.
I have also replaced 2 of the power trannies that had shorts.... ALL 4 now measure fine when out of the circuit.
Power resistors were also replaced (four 0.47ohm 2w resistors)
I have tested the transistors and bridge rectifier diodes and theyre all just fine BUT..
When i turn the darn thing on it it hums for a second then takes out one of the circuit breakers(there are three in total..one on the back labelled 1.25a...& two paired up inside, one is 1.25a(this is the one that always blows) and a 0.8a).
In one of the pics you can see 2 pairs of red and yellow wires leading up to the 2 breakers. The one that gets the red wires is the affected circuit breaker.
I cant really find anything on the schematic but its a pretty simple circuit thats proving to be a headache.
Im thinking of replacing all the resistors..i have noticed that one of the 20k trimpots looks a little dirty but could be some sort of damage? So far i have not tampered with the trimpots.
What other steps can i take to see what the deal is?
Im handy with a multimeter and i have an esr meter as well. Thanks!
Nikko TRM-210
So i got this thing strictly to fix up (there was distortion on one of the channels.)
WHAT I HAVE DONE..
I first recapped the whole thing. One cap was in the wrong way and it blew, damaging a resistor in the process that ive since replaced.
I have also replaced 2 of the power trannies that had shorts.... ALL 4 now measure fine when out of the circuit.
Power resistors were also replaced (four 0.47ohm 2w resistors)
I have tested the transistors and bridge rectifier diodes and theyre all just fine BUT..
When i turn the darn thing on it it hums for a second then takes out one of the circuit breakers(there are three in total..one on the back labelled 1.25a...& two paired up inside, one is 1.25a(this is the one that always blows) and a 0.8a).
In one of the pics you can see 2 pairs of red and yellow wires leading up to the 2 breakers. The one that gets the red wires is the affected circuit breaker.
I cant really find anything on the schematic but its a pretty simple circuit thats proving to be a headache.
Im thinking of replacing all the resistors..i have noticed that one of the 20k trimpots looks a little dirty but could be some sort of damage? So far i have not tampered with the trimpots.
What other steps can i take to see what the deal is?
Im handy with a multimeter and i have an esr meter as well. Thanks!
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