Component identification help

[Ken.P]

I'm attempting to repair a tillerpilot for my sailing boat, basically an electric motor cotrolled by a fluxgate compass (I think!).

The fault is that it will drive the motor one way, but not the other. It's been suggested that the drive transistors might be the problem. If I can find replacements I'd be able to at least attempt the repair.

If I'm correct, the parts I need are the four near the top of the pic. They have "GE C10681" on them, but I'm having no luck finding that part number online.

Any help would be appreciated.

Thanks. Ken.

 

[daddles]

Those are a bit of a strange package -- similar to a TO220, but not the same.

I would suggest you first focus on finding the root cause rather than assuming the transistors are at fault. While the problem may be the transistors, it could also be something else.

Have you contacted the manufacturer for a circuit schematic? They presumably could help you find replacement parts too. Without the schematic, you're forced to troubleshoot things blind.

One of the advantages you have is that it sounds like half of the circuit works. This allows you to compare the good working parts with the nonworking parts. Where you see differences then gives you a clue about where the problem's cause lies.

Do you have a digital multimeter? If not, you'll want one to help you make measurements.

My first task if this were mine would be to spend effort locating a schematic. Then I'd start comparing voltage and resistance measurements between the known working section and the nonworking section.

Some of the other folks on this board with better electrical skills than I have will likely be able to give you more guidance. But, if I haven't mentioned it, first try to locate a schematic.

 

[Ken.P]

Thanks for the suggestions, glad it wasn't just me that couldn't find it!
I'll try and get hold of a diagram to work from, but it's about 20 years old....

 

[ModemHead]

It's probably a C106B1. Which is an 4A 200V SCR in a TO-202 package.

http://octopart.com/partsearch/#search/requestData&q=C106B1

 

[KJ6EAD]

You can replace it with a NTE 5455.
http://www.nteinc.com/specs/5400to5499/pdf/nte5452_58.pdf

 

[Ken.P]

Thanks again.

Just need to find a supplier without ridiculous postal charges now....