Thread: Thandar TG2001
View Single Post
Old 16th May 2021, 4:01 pm   #11
Marconi_MPT4's Avatar
Join Date: Mar 2011
Location: Dorset, UK.
Posts: 427
Default Re: Thandar TG2001

Originally Posted by Hydrocarz View Post

I replaced Q8, This transistor still overheats... IC7 it's getting pretty hot so I replaced it, and it's still getting hot..
Taking Q8 in isolation, for overheating condition first ascertain if the +16V and -16V supplies are correct. Check D5 zener (5V6) and Q7 (2N3904) for leakage or short circuit and then finally check D4 (BAT181). Estimate about -10.4V on Q8 collector and -0.7V on Q8 base with VR29 centred.

For IC7 check power supplies -12V and +16V on pins 4 and 8 respectively, also be inclined to check D8 for leakage or short.

To an optimist a glass is half full; a pessimist half empty; an engineer twice as big as need be!
Marconi_MPT4 is offline   Reply With Quote