There's an LM309 transistor (U67) in my primetime 93 that runs super hot. after about 3 minutes you can't touch it. I measured one leg at 5v, which is correct. the other leg should be 8.5v but measures 10.4v. The same transistor in my other primetime gets only warm to the touch. I'll try to post the schematic (pg.98 in the service manual) but if i can't,... there is a 4.7uf 16v cap off each of the outside legs of the transistor. (C198 & C199). The voltages are correct at the various test points I've measured, as indicated in the manual.
I am wondering if the transistor could be going bad, or if a nearby component may have drifted in value enough to elevate the voltage going into, and then out of the transistor.
The unti was acting up- all headroom lights lit- which of course was fixed by reseating all boards.
Just wondering if I've got an inevitable failure here. thanks very much,