always on mod

A forum devoted to mod, tips and suggestions for upgrading and rehousing your VERY CHEAP commercial stompbox to near boutique excellence.
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elframbo
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Joined: 15 Jan 2019, 01:55

Post by elframbo »

I have a Sansamp GT2 and the footswitch spring seems to have worn out. It will sometimes engage, but not often. My soldering iron is terrible and I'm not that great at de soldering in the first place. So I cannot seem to remove the circuit from the casing to replace the spring.

So I'm wondering if anyone can tell me how I can short out the foot switch to be in an always-on state. Not ideal I know, but I'm fine with it as long as I have it working when I want it to work.

Thanks for any help you can provide, I have a photo of the back of the board right where the switch is and I need to know if I can short a combination of those pins to set this to always on.

The image below is of the back of the circuit board right where the button is, Those six larger solder points seem to be at least in part under the switch.

https://www.aronnelson.com/gallery/main ... ewsIndex=1

The image below shows the schematic, can anyone tell me what two solder points I would need to short to put this in an always on state? The last link is the other side of the board.
http://www.axiomdrift.com/schematics/GT-2pn.gif

http://www.axiomdrift.com/schematics/GT-2%20board.jpg

Thanks!

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deltafred
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Post by deltafred »

Welcome to fsb.

The bypass switching is performed by the 2 FETs at the right hand side of the schematic. The control circuitry for these is not shown.

If you want it permanently on one way is to remove both FETs and put a link between the drain and source connections of the lower one.

If I did this I would put a note in the box, along with the schematic and the FETs in a small plastic bag, to say what I had done.
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elframbo
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Post by elframbo »

Hey, Thanks for the reply, and links! This looks a bit more complicated than I thought it would be. I need to get a better soldering iron anyway. So I think removing the board, replacing the spring and switch is the way to go.

Any suggestions on removing the board from the case? As far as I can tell there are several anchor solder points around the input and output jacks. I've tried this before, but de-soldering didn't go very well. I have solder braid and even a small solder vacuum, but I'm not sure if it's just that the soldering iron doesn't heat up well enough to keep the solder liquid while I'm trying to remove it, or if its just my technique.

Also, can someone link, or tell me where I can buy a replacement spring and switch?

Thanks again!

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