Рет қаралды 11,183
This JCM 800 landed on my bench had cutout issues as reported and was apparently blowing out fuses. This sounded strange, but since it was blowing out fuses, this is going to have to be put into service position and troubleshoot with the power-off. This will start with a visual inspection.
The visual inspection immediately reveals the first issue, which was expanding electrolytic capacitors. Also oxidation is exhibited in the tube sockets. The underside reveals capacitor leakage.
During a fuse inspection it was found that the owner was attempting to put higher than rated fuses in the HT side in an attempt to keep the amp running. Hopefully this did not cause any internal damage.
The tube sockets were all hit with deoxit after being individually inspected and each tube tested, one finals tube was found to be shorted, very interesting.
A strategy is assembled to deflect the circuit board out of the way. This is required to reach one capacitor. With that, all of the caps are swapped out one by one.