Hi all, new to the forum.
I've got this unit on my bench. When I received it, I had opened it up to find bad solder joints and a burnt R49 resistor. According to the schematics, r49 is a current limiter for the preamp plates. I replaced it, but that 2W resistor is on the verge of burning up again only in standby. It registers over 140F on the temp scanner and would suggest there's an excessive current draw within the preamp stage. I've checked all the caps for the plate supplies and the filter caps (c14/c13). I am getting about 25-30Vac coming through the resistor and this doesn't seem right to me. Also,in standby, the mute isn't working as you can still get signal on the output tubes.
I've got 3 resistors that are registering out of the 1% tolerance, but even at 10%, I can't imagine the current being that high that it would burn through a 2W resistor when it should have been over rated to begin with.
I've swapped V1-V3 individually to see anything changed and I'm not seeing anything significant. Has anyone else seen this issue? Can anyone point me in the right direction? I'm running out of ideas here.
I've got this unit on my bench. When I received it, I had opened it up to find bad solder joints and a burnt R49 resistor. According to the schematics, r49 is a current limiter for the preamp plates. I replaced it, but that 2W resistor is on the verge of burning up again only in standby. It registers over 140F on the temp scanner and would suggest there's an excessive current draw within the preamp stage. I've checked all the caps for the plate supplies and the filter caps (c14/c13). I am getting about 25-30Vac coming through the resistor and this doesn't seem right to me. Also,in standby, the mute isn't working as you can still get signal on the output tubes.
I've got 3 resistors that are registering out of the 1% tolerance, but even at 10%, I can't imagine the current being that high that it would burn through a 2W resistor when it should have been over rated to begin with.
I've swapped V1-V3 individually to see anything changed and I'm not seeing anything significant. Has anyone else seen this issue? Can anyone point me in the right direction? I'm running out of ideas here.