Field Kit FX broken 9V DC input
#1
Sensors 
I have a field kit Fx and some days ago I inadvertently plugged in another 9V adapter with reversed polarity...  and since then it hasn't turned on anymore.
I've had it for years so it's out of warranty, but I can try to repair it myself.
I would need to know which piece is the one that may have broken (9v to 12V converter???) and if it may be where it is located.
It works with eurorack power so must be something in the DC power.
Thanks a lot,
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#2
(12-09-2022, 11:22 PM)synthi Wrote: I would need to know which piece is the one that may have broken (9v to 12V converter???) and if it may be where it is located.
It works with eurorack power so must be something in the DC power.

Yep, that is right. If it doesn't work with the 9V adapter but with Eurorack power, then one of the internal DC switching ICs went bust. A few years back we actually made a nifty little PDF about this very repair, I've uploaded it for you here.


When someone plugs in a wrong power supply and the Field Kit FX stops working, in 90% of the cases, it's the +12V chip that gets fried. You could take a magnifying glass and have a really close look at it. If it looks damaged, like e.g. having a small bubble or crater in its housing then it's definitely that one.

Hope that helps! Let us know please!
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#3
(12-12-2022, 04:25 PM)chrisi Wrote:
(12-09-2022, 11:22 PM)synthi Wrote: I would need to know which piece is the one that may have broken (9v to 12V converter???) and if it may be where it is located.
It works with eurorack power so must be something in the DC power.

Yep, that is right. If it doesn't work with the 9V adapter but with Eurorack power, then one of the internal DC switching ICs went bust. A few years back we actually made a nifty little PDF about this very repair, I've uploaded it for you here.


When someone plugs in a wrong power supply and the Field Kit FX stops working, in 90% of the cases, it's the +12V chip that gets fried. You could take a magnifying glass and have a really close look at it. If it looks damaged, like e.g. having a small bubble or crater in its housing then it's definitely that one.

Hope that helps! Let us know please!

Thanks!
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#4
(12-12-2022, 04:25 PM)chrisi Wrote:
(12-09-2022, 11:22 PM)synthi Wrote: I would need to know which piece is the one that may have broken (9v to 12V converter???) and if it may be where it is located.
It works with eurorack power so must be something in the DC power.

Yep, that is right. If it doesn't work with the 9V adapter but with Eurorack power, then one of the internal DC switching ICs went bust. A few years back we actually made a nifty little PDF about this very repair, I've uploaded it for you here.


When someone plugs in a wrong power supply and the Field Kit FX stops working, in 90% of the cases, it's the +12V chip that gets fried. You could take a magnifying glass and have a really close look at it. If it looks damaged, like e.g. having a small bubble or crater in its housing then it's definitely that one.

Hope that helps! Let us know please!

Hi chrisi,

I have a similar issue - I'm also trying to troubleshoot and fix a broken 9v input (while the 12v Eurorack works).

I'm trying to identify which IC might have fried to order a replacement, but they all look good to me..? Here is a link - would you mind taking a look..

https://imgur.com/a/Ai6VwjO

Is there another way to test..?

Thank you!
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#5
Hey! If it works in Eurorack but not via the power adapter, this is the best test one can do without proper lab equipment. It means either the +12V or the -12V chip is broken. In you picture it looks like the +12V chip might have a tiny bump on its case but it's hard to day because those bumps are teeny tiny and it's bit hard to see. If you look at it with a magnifying glass you might spot the small bump in the bottom left corner.
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