Re: Another request for assistance - this time a Green Rhino

Posted by Kalimna on Jul 26, 2017; 1:44am
URL: http://guitar-fx-layouts.238.s1.nabble.com/Another-request-for-assistance-this-time-a-Green-Rhino-tp39219p39239.html

Prior to discovering the missing link (underneath the LM833), I had checked the pin voltages and the buffer transistors all had good supply voltages, but almost nothing at emitter or base. Both chips read 0V on the appropriate pins, but less than 1V on the remainder (LF347 had good supply voltage).

Once the link was inserted, the pedal seemed to work fine so I havent run the DMM over it again. Perhaps I should, for completeness sake.

The above applies to the second build, I abandoned the first as I had tried the suggestions with nothing obvious turning up (short of replacing the original chips, which certainly helped). I had knifed the gap inbetween tracks with a stanley knife, and I suspect this made any shorting worse due to new slivers of copper being created! However, I shall try your suggestion of a steel rule next time - much less likely to damage the copper.

I did do a continuity test along the ground path (to the IC's at least), but found only a minimal resistance (about 0.5 ohm) between the jack socket and the IC.

Cheers,
Adam