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Hello Forum:
I have a Marshall JCM2000 DSL 401 that has no filament voltage to the three pre-amp tubes. I found the solder joints on the bridge rectifier, and the two filter capacitors broken and re-soldered all the joints, tested for filament voltage, the then assembled the unit back together. The amp worked well for several hours, and after moving the amp in the car to the gig, turn it on, and the sound fades out, as if the filter capacitors were discharging and not charging up from the power supply.
I the moved the amp back to my workshop, and opened the unit and re-soldered all the solder joints associated with the filament and power supply circuits.
The amp now had no sound.The channel switching lights don't even come on. I checked the two zener diodes, and I am seeing +15 and -15 VDC respectively, but still no sound or channel LED lights. I have checked the obvious (connectors from the channel switching board to the main board, all the connections from the transformers to the main, board, etc.
Has anyone experienced this problem?
I have the schematics, and looking again to see if I missed anything.
All comments are appreciated.
Jay D.
I have a Marshall JCM2000 DSL 401 that has no filament voltage to the three pre-amp tubes. I found the solder joints on the bridge rectifier, and the two filter capacitors broken and re-soldered all the joints, tested for filament voltage, the then assembled the unit back together. The amp worked well for several hours, and after moving the amp in the car to the gig, turn it on, and the sound fades out, as if the filter capacitors were discharging and not charging up from the power supply.
I the moved the amp back to my workshop, and opened the unit and re-soldered all the solder joints associated with the filament and power supply circuits.
The amp now had no sound.The channel switching lights don't even come on. I checked the two zener diodes, and I am seeing +15 and -15 VDC respectively, but still no sound or channel LED lights. I have checked the obvious (connectors from the channel switching board to the main board, all the connections from the transformers to the main, board, etc.
Has anyone experienced this problem?
I have the schematics, and looking again to see if I missed anything.
All comments are appreciated.
Jay D.
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