Fingolfen
Well-known member
So, one of my Thagomizers came back from the wilds with a whine anytime it was plugged in (photos below). The grounding was fine, I replaced the charge pump for good measure, just in case. Plugged it back in - same issue. Mostly on DC plug, but 9V battery was starting to do it as well. I then noticed that the zener diode on the daughter board was hot... I mean, a couple of hobbits were about to throw a ring into it hot. I figured it was toast, so I snipped it out of the board and instead of a 0.7V forward voltage drop and open line reverse, it was about 0.1V forward voltage drop... and about 0.12V reverse voltage drop. This is a 1N4742A zener from Mouser, and I've never had one fail before. Short of it having a defect or being damaged on install (both of which would be firsts), what else could cause this? I'm wondering if it was accidentally put into the wrong power supply at some point...
Edit: After replacing the zener with a new one, the pedal is once again working normally and after 30 minutes of playing (granted I'm not the hottest guitarist out there... nyuk nyuk nyuk...) no issues - new zener is still cool to the touch...
Edit: After replacing the zener with a new one, the pedal is once again working normally and after 30 minutes of playing (granted I'm not the hottest guitarist out there... nyuk nyuk nyuk...) no issues - new zener is still cool to the touch...
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