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T912 missing trace solved- quick LM3086 question

Dave Seiter
 

Man, are my skills getting rusty! Took me way too long to determine that Ch1 on my T912 wasn't working because one of the xstrs in U4134 (LM3086) wasn't passing the signal. (Ch1 -vert sig path) Seems like an unlikely failure, but I guess anything's possible. It's going to be a hassle to replace, but it's my only portable storage scope. Anyone seen this failure before in a T9xx scope?

-Dave

tom jobe
 

Hi Dave,
The data sheet for the LM3086 says the transistors in it are general purpose NPN, so how about clipping the leads to the dead transistor and tacking in a generic TO-92 style transistor for now?
It appears that you have one of those three standalone transistors in the LM3086 to replace, maybe U4134A?
tom jobe...

On 7/20/2019 7:44 PM, Dave Seiter wrote:
Man, are my skills getting rusty! Took me way too long to determine that Ch1 on my T912 wasn't working because one of the xstrs in U4134 (LM3086) wasn't passing the signal. (Ch1 -vert sig path) Seems like an unlikely failure, but I guess anything's possible. It's going to be a hassle to replace, but it's my only portable storage scope. Anyone seen this failure before in a T9xx scope?

-Dave