SOLVED Burned charge pump?

giovanni

giovanni

Well-known member
Hey guys! I haven’t worked on builds for a while and I’m slowly getting back into it. Today I boxed a Transcendence Boost in a 1590B which was exciting! However when I put the charge pump in the socket I realized I put it in backwards. So I removed it and flipped it but in the process I may have squeezed the chip too hard with needle nose pliers. I plugged the pedal in and it was quiet. Opened the back while plugged in, saw a bit of smoke come out and the chip was scolding hot 🥵 and it smelled burnt.

Could it be that I damaged it while pulling it out of the socket and then it just melted? Or maybe I had a defective chip (got it from Tayda)? I had measured each component before installing and I am pretty confident in my solder joints so I am inclined to exclude other build issues, including shorts, but before trying a new chip, is there anything I should check on the board? Anything that would have caused the chip to burn?

Almost forgot: another small issue I had was that the power plug’s center pin was bent towards the outer ring. I think it got melted a bit while soldering (I did see some solder flow towards it). I bent it back into place and it seemed fine. I assume it would either work or not (9V would short to ground). Should I replace it before trying a new chip?

Any help is appreciated!
 
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Have you tried testing the power plug for continuity, ie a short?

I had a DC jack go south on me recently and fried a charge-pump IC in a build that I don't have access to until I visit my friend overseas.


My bet is as you say, you squeezed the pliers too hard — ICs have such tight tolerances inside I could see it being easy to mess one up just squeezing it.
 
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Feral Feline said:
Have you tried testing the power plug for continuity, ie a short?

I had a DC jack go south on me recently and fried a charge-pump IC in a build that I don't have access to until I visit my friend overseas.


My bet is as you say, you squeezed the pliers too hard — ICs have such tight tolerances inside I could see it being easy to mess one up just squeezing it.
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I’ll definitely check continuity before putting a new chip in, thanks for the suggestion!
 
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It’s also worth suggesting pulling socked chips out a more gentle way. While I have a tool for that (sort of a wide tweezers with little hooks bent in on each end), I almost always just use a fine slotted screwdriver, stuck under one end, and then rotated slightly to pop the legs out of the sockets.
 
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Or there is something wrong with your circuit, as was the case for the pedal I gifted to a friend.

In my build, I was under deadline and didn't get to test it before giving it away. The charge pump fried right away. I'll have to diagnose and fix it when I visit him, as shipping overseas is too expensive and I'll be visiting at some point anyway.
 
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I don’t think there’s anything hotter in the universe than a backwards charge pump. Once I plugged one in backwards, and two seconds after applying power and getting no sound, I realized, unplugged the power, and went to pull it out, and it literally melted the shape of the ic, Major Thot (Raiders of the Lost Ark) style, into the pads of my thumb and index finger.
 
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I
Feral Feline said:
Or there is something wrong with your circuit, as was the case for the pedal I gifted to a friend.

In my build, I was under deadline and didn't get to test it before giving it away. The charge pump fried right away. I'll have to diagnose and fix it when I visit him, as shipping overseas is too expensive and I'll be visiting at some point anyway.
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yeah that’s what I am wondering. The power plug is the only thing that didn’t go smooth with this build and I can’t imagine anything else that could fry a charge pump chip. And honestly I am struggling to figure out how that could fry it.
 
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Bricksnbeatles said:
I don’t think there’s anything hotter in the universe than a backwards charge pump. Once I plugged one in backwards, and two seconds after applying power and getting no sound, I realized, unplugged the power, and went to pull it out, and it literally melted the shape of the ic, Major Thot (Raiders of the Lost Ark) style, into the pads of my thumb and index finger.
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I have a breadboard with a DEEP dip-8 sized melted crater in it because of this too lol
 
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giovanni said:
I

yeah that’s what I am wondering. The power plug is the only thing that didn’t go smooth with this build and I can’t imagine anything else that could fry a charge pump chip. And honestly I am struggling to figure out how that could fry it.
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Maybe a short under the socket?

Under-socket shorts are easy to miss when trouble-shooting. At least, that's what a friend tells me...

Undershorts sockets aren't as easy to miss when trouble-shooting, though, says a friend.
 
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Bricksnbeatles said:
I don’t think there’s anything hotter in the universe than a backwards charge pump. Once I plugged one in backwards, and two seconds after applying power and getting no sound, I realized, unplugged the power, and went to pull it out, and it literally melted the shape of the ic, Major Thot (Raiders of the Lost Ark) style, into the pads of my thumb and index finger.
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2 observations. First, I melted the leads of a battery snap together inadvertently one time when they were touching when I snapped the 9 volt battery into the snap. That was exciting. Second, I once smelled a LM386 … well, I smelled hot electrical smell and plastic and then realized I had done a bad bad.

Be careful out there, friends! Electrons mean business.
 
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I got some good news: I tested continuity on the power plug and made sure I had no shorts. Then I went ahead and put a new charge pump IC in. And what do I find? I had also installed the OPA2134 upside down! So I flipped that, boxed back up and, tada, the pedal fired right up! The lesson here is to always remember the first rule of pedal building: be patient, triple check all components, don’t use excessive force, wash your hands, don’t pick your nose, at least not before building, maybe take fewer edibles while building, always salt your pasta water, never order lamb because you don’t like it etc. wait what was I talking about?
 
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giovanni said:
I got some good news: I tested continuity on the power plug and made sure I had no shorts. Then I went ahead and put a new charge pump IC in. And what do I find? I had also installed the OPA2134 upside down! So I flipped that, boxed back up and, tada, the pedal fired right up! The lesson here is to always remember the first rule of pedal building: be patient, triple check all components, don’t use excessive force, wash your hands, don’t pick your nose, at least not before building, maybe take fewer edibles while building, always salt your pasta water, never order lamb because you don’t like it etc. wait what was I talking about?
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I'll have the lamb, you can have the pasta
 
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