[GreenKeys] ST6 Autostart debugging

[Eugene Hertz]

Hello all,

Trying to debug an autostart board (actually 3 of these boards). I am trying to follow along in the Hoff article entitled, "Troubleshooting the ST-6 demodulator" (thanks, Tom!)

In this article, it mentions "test point 2" and U5, however, in my ST6 Manuals, I could not locate any such test point, or chip called U5.

Can someone point me in the right direction? I wanted to follow along in the circuit theory from Hoff with my one working board, then follow along again in the 3 bad boards to see if I could locate the problem.

Thank you very much.
Oh yeah. one more request. One of 1-850 boards has had its pot snapped off.  It is R107 for those following along at home. It is a pcb-mounted pot that typically has a blue wheel to rotate. They are many of these in the ST6. Nominal value is 5K, but I would guess other values would work well too.  Any chance someone has one they could slip in the mail? Let me know $$. Yes, I could get it from mouser, but I don't have much else I need to buy right now.

thank you and regards!
Eugene