Frost drive hot charge pump.

flippy69

Member
I would like to start off by saying that I’ve built 10 of this exact design with zero issues of this nature. I finished this pedal last night. Sounded fantastic with no issues. Plugged in this evening only to get no sound but smell something burning and realized that something was wrong. I did some research and learn that there are issues with charge pumps so I replaced that charge pump ( different batch) same thing happened so it immediately turned off.
Does anyone have any ideas of what’s going on?
 
I would like to start off by saying that I’ve built 10 of this exact design with zero issues of this nature. I finished this pedal last night. Sounded fantastic with no issues. Plugged in this evening only to get no sound but smell something burning and realized that something was wrong. I did some research and learn that there are issues with charge pumps so I replaced that charge pump ( different batch) same thing happened so it immediately turned off.
Does anyone have any ideas of what’s going on?
Check and make sure C100 -10uF & C101 - 47uF are correct values & polarity is correct first.
Pull the TC1044SCPA & Test for continuity on Socket pins.
 
I am thinking that a short somewhere could draw too much current and burn out the power too. If it was working well and sounding good to start with then I would be looking for short that formed since - piece of cut off lead that moved, jack that twisted around and shorted to the case etc
 
Check and make sure C100 -10uF & C101 - 47uF are correct values & polarity is correct first.
Pull the TC1044SCPA & Test for continuity on Socket pins.
After reading that it was working fine & it was moved and plugged in again as PJS listed, there is a chance a blob of solder or a piece of cut lead may have lodge across the pads. Thoroughly check & hang it upside down over your work bench and give it a good tap to see if anything falls out.
 
A picture is worth 1,000 hours of debugging time.


Maybe the short was there already, and as you used it, it heated up the short enough to flow solder and cause the short to go from a trickle to a flood...

Sorry. I got nothing but bad jokes. I'll let myself out...
 
Did you sort this out?
Yes yes it did sorry I didn’t check back in. It turns out I somehow miss wired two connections on the foot switch. Don’t ask me how I did something so dumb. But as I sat looking at the circuit, I noticed it from my memory of wiring these. I reversed the two wires, it immediately worked and the chip stopped heating up, in fact the charge pump works perfectly despite getting seriously hot.
One thing that still puzzles me though, is when I first finished the pedal and plugged it in, it worked perfectly. How is that possible? I even recorded me playing through it initially. So that part of the mystery is still unsolved.
 
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