Help debug a Roger Mayer Octavia

Started by carrejans, June 21, 2010, 05:57:06 AM

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Pedal love

Ok my friend has a built one the same as yours and all the voltages you have, seem to be uniform except the emitter on q1. It should be higher. You should check this area and post back. Remember the emitter is turned upside down so it is in the place of where th collector is normally. That means you should back track all the way to the applied voltage of q2 and around q2's collector. Post what you find.

Jay

You definitely need to sort out Q1.  It's either a base emitter short or a dead transistor - swap it out if you can't see an obvious short.

Pedal love

After the transistors, check all of the mechanical parts- switches, pots, jacks, etc.

Govmnt_Lacky

According to the layout in the first post. The most logical place to look (to me  ;D) is a SHORT between Q1s Emitter solder pad and the right side solder pad of the 820K resistor. This would cause the same voltage on Q1s Base & Emitter as you are posting.

Bet you a Coke that those 2 pads are shorted or solder-bridged!  ;)
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Pedal love

Quote from: Govmnt_Lacky on December 19, 2010, 05:35:55 PM
Bet you a Coke that those 2 pads are shorted or solder-bridged!  ;)

Could be. I really don't like this layout. Too many of the pads are too close together.

carrejans

After one and a half year, I picked up this project again.

I swapped the Q1 transistor again. Just like I did back then.
Now it worked...  :icon_eek:
So back then, the new transistor was probably a bad one again. (or soldered to dead) So, I thought there was nothing wrong with this tranny.
Pfff....  :-[

Happy now.  ;D

Thank you all for the help!!!