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Green Bean Dead Sort Of NOW FIXED

Started by BrianS, June 05, 2016, 12:57:35 AM

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BrianS

I had this working last Sunday. Took it out of the box to finish it and when I put it back in it has a horrible squealing coming out with the effect behind it.  I reflowed all the off board wiring, changed out 2 ICs and the transistors, replaced the power wire with shielded wire, grounded the output Jack lug and replaced the dc Jack. Nothing helped or changed the problem. My voltages are real close on the IC but the transistor bases are .78 and 1.12 off of the build doc. The transistors are BC 550s.  The component side picture was taken before I put the shielded wire on and the negative power wire broke off when I flipped the board to take a picture. Voltages were taken before it broke.  This is very perplexing since it was working perfectly before I took it out to finish it. Any help would be appreciated. Oh I ran this off of 3 different power supplies (battery, wall wart, and my board supply same results with all). Thanks in advance.

IC
1. 4.45
2. 4.54
3. 4.36
4. 0
5. 4.44
6. 4.45
7. 4.45
8. 8.93

Q1
C - 8.89
B - 2.80
E - 3.39

Q2
C - 8.89
B- 2.81
E - 3.40







jimilee

Did you check that your transformers aren't loose, and that your ground you soldered back on isn't touching anything else?


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

BrianS

Got this back up just now. What an ordeal. I believe this is the first time I have troubleshot a pedal and got it working. I might have went the long way around getting it working, i.e., I basically put everything in new off board (jacks, wiring and 3pdt) and the squealing stopped but I was still getting no sound through the board.  Started probing it and my audio probe broke.  Long story short I was getting good sound all the way up to R5 and it stopped there.  Reflowed it nothing.  I replaced the resistor and put a new IC in and it fired up. Really missed this pedal this morning while playing.