TCI box Anyone know of a test

Specdog

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I suspect my TCI unit has failed. The symptom of no spark is on the right cylinder only. I've done all the tests I can think of on the other parts and they all show normal. Coils spec'd out OK but one was high but still sparks. Pick up coil normal. The failed spark follows the coil harness when you switch them. I've traced wires and they have continunity. The manual says at this point to change the TCI. Before I get another one I took the old one apart half expecting to see a burned out circuit. The unit looks perfect. Does anyone know of any definitive tests one can do?
 

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Sorry, I don't know of any further testing, short of removing components and testing them individually. It sounds like you have done all the testing that can be done. It will probably be easier and faster to just source another module. I'd suggest keeping yours and replacing all the components so you have a spare in the future.
 
Someone posted some links in the 'what did you do today' thread which I found very useful myself. Can't remember who exactly it was, but thanks to that person nonetheless :)

here is what I used

and a more elaborate:

here ya go

basically what I did on my xs is I re-soldered all the visible joints. Started out with all the ones that looked potentially dry, but then decided it's quick and easy and I might as well do them all. After I was done I sprayed it down with some electrics protecting spray from the car parts shop. My TCI hasn't given any problems since.
 
Thanks for that Willem. I read through it; very interesting but it's beyond what I can do with my electric soldering gun. I didn't even know there was a solder sucker. I'll get a TCI on eBay.
 
I have a 78 that was points and when I switched it to TCI from a parts bike the timing was very erratic when I had my light on it (not bad but 3-5 degrees plus or minus). I replaced all of the electrolytic capacitors (look like round cans and they usually go bad after 10-15 years) and now my ignition fires on the dot every time.
 
I don't have a solder sucker either. My dad does but he lives two hours away so I didn't use one when I rebuilt my TCI. Honestly, just sticking the solder gun onto the joints to melt and re-flow them is plenty. Don't need to go all the way with replacing components. A TCI from ebay will be just as old and unreliable, I strongly recommend you try ;)
 
I agree with willem. Re-flow all the solder joints to make them nice and shiny. Sometimes that's all it takes. Replacing the components (capacitors, transistors, etc) really isn't difficult. You just need to have patience and make sure everything is de-soldered enough to be removed without force. I have succesfully rebuilt my module TWICE following the second link he posted.:doh: First time was when I first bought the bike. The second was when I shorted the battery and burned up a capacitor.:banghead: Solder suckers are handy, there is also copper weave. You can find both at RadioShack or similar store. Good luck if you take this route, otherwise, good luck with finding a replacement module that works.:thumbsup:
 
Do contenuety test on the resistors and diodes,that will tell you if you have bad component in your tc.If you have a multimeter that beeps when checking that will help.
Another thing did you remove the board and check the backside?
 
Someone posted some links in the 'what did you do today' thread which I found very useful myself. Can't remember who exactly it was, but thanks to that person nonetheless :)

here is what I used

and a more elaborate:

here ya go

basically what I did on my xs is I re-soldered all the visible joints. Started out with all the ones that looked potentially dry, but then decided it's quick and easy and I might as well do them all. After I was done I sprayed it down with some electrics protecting spray from the car parts shop. My TCI hasn't given any problems since.

Thank you for posting the guides.
I had the same problem with my TCI unit. Here is what I did:
- changed old transistors with new st901t transistors
- changed all electrolytic condensators
- resoldered all visible joints
After that the TCI worked just fine.
 
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