Bart Rydzynski
- Apr 14, 2016
- 39
- Joined
- Apr 14, 2016
- Messages
- 39
You have a good opportunity to learn from this problem. You theorize what the problem is and it's solution. Pull Q6 and see if the results match your theory. Yes? Great! No? Why not?
You have a good opportunity to learn from this problem. You theorize what the problem is and it's solution. Pull Q6 and see if the results match your theory. Yes? Great! No? Why not?
Replacing all the transistors may be your best bet since you do not have a transistor tester and cannot verify their performance. If you continue and enjoy working on transistor circuits, you may want to look into a transistor tester for your work bench. It will pay for itself in aggravation saved the first time you use it.
My pleasure. I really enjoy helping you because you have an eagerness to learn. Will be waiting for your next update. You too have wonderful week!
Regards,
Bart
Good evening Bart. I have a mystery on my hands. I received all the new transistors, tested them, checked the config and installed them all. Guitar Channel words but distorted. Mic channel works and I can control the distortion in the way you described earlier. The Bass channel has nothing. I checked C103 and have 60v on the + side when it should be 24. Checking Q4, Q5 and Q6 I do not have the correct voltages.... now the mystery.
While checking around I see R110 on the schematic listed as 10K. Printed on the circuit board it says 100K. I have previously replaced the resistor with a 100K and am wondering if there was a field bulletin on R110 being printed incorrectly and I need to put in a 10K instead. I am hesitant to change it now as I do not want to start blowing out transistors again.
Would you know from experience if sounds off. 100k does seem kind of high in that circuit config, but I defer to your expertise. Thank you sir..
Ron
This is what I have on Page 7 for R110
https://pbs.twimg.com/media/Cgh4BJNWYAAeMv-.jpg:large
And here is my schematic.
https://pbs.twimg.com/media/Cgh4UP3WgAEE39Y.jpg:large
I'll take voltage readings on the other transistors and report back.
C103+ has 60 volts and Q6-C has .46 volts? Check the resistance from the + lead of C103 to the lead of Q6-C. It should be less than one ohm.