Horrid intermittent on Transistor Black Box 1004 - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Ektalog · 11th Feb 2012, 4:17 am

"an intermittently failing transistor"

Setsappeal, this is just to thank you for your persistence and more so for your willingness to report on the final outcome. I so wish more people took the time to do it! I visit this forum once or twice a year but only now decided to register, to thank you.

I am trying to fix a bias issue in one [more recent] power amp. For my specific situation, no one, anywhere, ever suggested that I looked at the transistors. Yet, I kept thinking that it had to be one of them, despite all of them checking out fine.

Not having much time available, I was dreading the task of dismounting the trannies on the other channel to see if they fixed the issue on the bad side. I decided to try the web searches once more, to see if at least ONE soul had EVER found what I suspected.

On the strength of your posting, I felt that my effort my would not be wasted. I swapped transistors. TA DAHHH!!! Issue resolved. I just need to order the replacement for a matched pair.

Many thanks!

11th Feb 2012, 4:17 am	#21
Ektalog Retired Dormant Member Join Date: Feb 2012 Location: Florida, USA Posts: 1	Re: Horrid intermittent on Transistor Black Box 1004 "an intermittently failing transistor" Setsappeal, this is just to thank you for your persistence and more so for your willingness to report on the final outcome. I so wish more people took the time to do it! I visit this forum once or twice a year but only now decided to register, to thank you. I am trying to fix a bias issue in one [more recent] power amp. For my specific situation, no one, anywhere, ever suggested that I looked at the transistors. Yet, I kept thinking that it had to be one of them, despite all of them checking out fine. Not having much time available, I was dreading the task of dismounting the trannies on the other channel to see if they fixed the issue on the bad side. I decided to try the web searches once more, to see if at least ONE soul had EVER found what I suspected. On the strength of your posting, I felt that my effort my would not be wasted. I swapped transistors. TA DAHHH!!! Issue resolved. I just need to order the replacement for a matched pair. Many thanks!