03-08-2020, 08:39 AM
(This post was last modified: 03-08-2020, 08:41 AM by Mike Watterson.)
It only ever fades out straight after turning on. At least I think so.
Certainly monitoring the current is a good idea, as would be perhaps the voltages at some points with soldered on probe wires so it can be in the cabinet.
Two versions of the amplifier, hopefully only differing in layout. R4 and C12 (470nF) use a tag of the unused pole of the power switch, R4 being from the tag to the PCB. Initially this was puzzling as the actual switch contacts in use are at the PCB level and harder to see.
There are five electrolytics in that part of the radio. Perhaps C19 or C20 are the most likely culprits if it is a dodgy capacitor. Maybe if it's a capacitor reforming the fault will go away simply by running it.
I ran it over an hour this morning, it did come on, fade out and then after a minute or so gradually returned, a little distorted at first. Then it was fine. I turned it off for 15 minutes and just now turned it on and it's fine.
The Trader & R&TVS seem to use the same designations on this part.
Certainly monitoring the current is a good idea, as would be perhaps the voltages at some points with soldered on probe wires so it can be in the cabinet.
Two versions of the amplifier, hopefully only differing in layout. R4 and C12 (470nF) use a tag of the unused pole of the power switch, R4 being from the tag to the PCB. Initially this was puzzling as the actual switch contacts in use are at the PCB level and harder to see.
There are five electrolytics in that part of the radio. Perhaps C19 or C20 are the most likely culprits if it is a dodgy capacitor. Maybe if it's a capacitor reforming the fault will go away simply by running it.
I ran it over an hour this morning, it did come on, fade out and then after a minute or so gradually returned, a little distorted at first. Then it was fine. I turned it off for 15 minutes and just now turned it on and it's fine.
The Trader & R&TVS seem to use the same designations on this part.
