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fixing my brothers theremin Answered

My brother who has no electronics history bought a theremin kit from an Australian electronics store called jay car and or course it didn't work when he finished it, sp he gave it to me but in the electronics department i can only build kits with all the instructions there for me i dont know how to fix a problem with one. I have a multimeter here but im still completely not sure how to use it to find out whats wrong with the kit, it sounds dumb but i could post a picture of it but im pretty scure that would be pointless cos you wouldn't be able to see the components values. Can anyone give me some help in trying to figure out how to fix it cos i dont want to have to rebuy it and built it for him

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Kiteman
Kiteman

12 years ago

Is it not possible to desolder it and start again?

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Goodhart
Goodhart

Reply 12 years ago

Hopefully nothing was put in "backwards" when it was powered up and tested. Transistors are kind of sensitive that way. .

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craig3
craig3

Reply 12 years ago

thats what im thinking happened, and i can see on the board that a few "links" are missing. Im still trying to et the picture of it but i cant find my sisters camera

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Tool Using Animal
Tool Using Animal

Reply 12 years ago

Ha, I was going to say, make sure the links are in. Just solder a piece of wire, jaycar makes great kits, but they tend not to explain the "links", so if you don't know, it's just a piece of wire. Then check the caps for polarity issues, then try powering it up.

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Goodhart
Goodhart

Reply 12 years ago

The capacitors, the diodes, anything where polarity matters.

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craig3
craig3

Reply 12 years ago

it most certainly would, but before he went to test it, he put it into the project box it came with and i cant get it back out now

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caitlinsdad
caitlinsdad

12 years ago

Were any IC integrated circuit chips involved? Did those plug into sockets in the circuit board or did they need to be soldered in. Maybe those were damaged. I don't know how you would really be able to test if they were good or not without advanced equipment.

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craig3
craig3

Reply 12 years ago

i do believe they where but they where the kind where he had to solder a seat in that the chips plugged into, now that i think of it he might of gotten those mixed up

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caitlinsdad
caitlinsdad

Reply 12 years ago

There is a little mark to indicate where pin 1 is on a chip. Make sure the ICs are inserted with the pins aligned to match the right spot/orientation in the socket.

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Goodhart
Goodhart

12 years ago

if you post a picture, can you also scan in the schematic ? Or wasn't one included ?