Hello all, I've been greatly enjoying my VTA ST-70 for the last two months, but it went quiet yesterday. Blown fuse.
Could only find a 2A and 4A slow blow in local store yesterday evening, so I opted for a 2A and replaced it.
Perhaps 10 seconds or more after turning on the power, I hear a "zzzt" and saw a brief a blue-white flash in the vicinity of the rectifier tube, then all of the tubes went dark again. Another blown use. I think I saw arcing inside the rectifier tube.
Based on the troubleshooting thread, it sounds like either the rectifier tube or quad cap is the problem.
What is the best way to isolate the problem?
Should I test the quad cap before I replace the fuse and try to power up again? Is the procedure Bob describes for testing the quad cap in his reply Re: Blowing rectifier tubes appropriate for my situation?
I'm assuming I should remove all of the tubes and discharge the quad cap before doing anything else. Any other precautions to follow in addition to those described in the "Safety" sticky?
Recommendations for a replacement/spare rectifier tube? Original with the kit is a Ruby 5AR4C.
Could only find a 2A and 4A slow blow in local store yesterday evening, so I opted for a 2A and replaced it.
Perhaps 10 seconds or more after turning on the power, I hear a "zzzt" and saw a brief a blue-white flash in the vicinity of the rectifier tube, then all of the tubes went dark again. Another blown use. I think I saw arcing inside the rectifier tube.
Based on the troubleshooting thread, it sounds like either the rectifier tube or quad cap is the problem.
What is the best way to isolate the problem?
Should I test the quad cap before I replace the fuse and try to power up again? Is the procedure Bob describes for testing the quad cap in his reply Re: Blowing rectifier tubes appropriate for my situation?
I'm assuming I should remove all of the tubes and discharge the quad cap before doing anything else. Any other precautions to follow in addition to those described in the "Safety" sticky?
Recommendations for a replacement/spare rectifier tube? Original with the kit is a Ruby 5AR4C.