I’m servicing my M-120a power amp that had a noisy right channel. Swapped out a 2Sc2240 and 2SA970 in the input stage - seems to have fixed it.
These two components are on a part of the PCB that appears to have suffered some long term heat damage - nearby a 1W 39k resistor that seems to be the culprit.
Interestingly the service manual states this as needing to be a “flameproof metal film resistor”. I’m tempted to just replace with a 3W normal metal film resistor, and mount this on the reverse side of the board to keep heat away from other components. Any problem with this approach? What’s different about flameproof specd resistors apart from obviously not catching alight if overheated? Do they behave differently when heat stressed? Do they fuse? Should I be using one as a replacement?
These two components are on a part of the PCB that appears to have suffered some long term heat damage - nearby a 1W 39k resistor that seems to be the culprit.
Interestingly the service manual states this as needing to be a “flameproof metal film resistor”. I’m tempted to just replace with a 3W normal metal film resistor, and mount this on the reverse side of the board to keep heat away from other components. Any problem with this approach? What’s different about flameproof specd resistors apart from obviously not catching alight if overheated? Do they behave differently when heat stressed? Do they fuse? Should I be using one as a replacement?
