TCI repair question

Hi,

there have been many instances of people speaking of checking and repairing a TCI for cold something or other ... basically broken solder joints. Obviously, to do so they have to open the TCI ... I cannot for the life of me figure out how you do so? I can find no seams or such to take apart. Could someone please clue me in on how to safely open it up? (Pics would be *AWESOME*)

Thanks,

 

They are talking about "cold solder joints" on the circuit board. They are solder joints that appear good but upon close inspection are not. The easy fix is to reheat the joint to flow the solder again. I don't have a pic but a visual clue is a tiny crack surrounding the wire in the niddle of the joint, usually only visible with a magnifying glass.

Another problem with the TCIs is corosion in the diodes from moisture.
http://xjbikes.com/Forums/viewtopic/t=3 ... diode.html

Don't know specifically about your TCI but most have a cover with 4 screws to access the back of the board. Remove them and expose the board. The board can only be removed from the case by unsoldering the pin connections at the end.

 

Yes, cold solder joints. I finally recalled the phrase earlier today.

As far as opening one ... the one I have sitting here in front of me by all appearances is one large black chunk of plastic. I see no seams or such. There are two small holes on one of side of the bottom of the unit. They are literally on the edge of the box, but they are very small and I am not sure about tinkering with them.

If someone has some guidance, it would sure be appreciated.

 

The TCIs on the XJ700 is a sealed unit. The only way to take it apart is cut it open. If you know it is bad you cant make it any worse. I would be sure its bad before I did that.
Is the bike running now?

 

It should have four screws. It is possible someone glued yours, I suppose, but I can't imagine any other reason it shouldn't be obvious. Mine opened easily enough, four corner screws.

However, as he said, to take off that first board and get inside is a pretty skilled technique--you have to de-solder pins to take it out, which is not a straighforward task like turning a screw driver.

 

There are pics and a detailed guide on the XJCD; there is a link to a torrent for the XJCD in the XJCD thread a page back or so that I put up, you can download it in a day or two if you have a decent connection.

 

The style with the 2 little holes opposite the end with the connectors, by memory, require you to remove the cover at the terminal end to slide out the board, which is generally stuck in.
I have one from a GSX that I think is similar, will post up a pic soon showing more.

 

Unfortunately, these holes are not at the opposite end. If you turn the unit over so you are looking at the back with the connectors pointed up, they are on the left hand side. If you were to line up a small bit with the exact center of the bit on the edge and drill in about 5 or 6 mm, that is what you'd have. Looking from the side, they are half circles. Looking from the back they look like a channel cut out of the bottom piece. Strange, eh?

Unfortunately, I don't KNOW if it is bad and I have no way to test.

 

So not like this then?

 

I expect so ... add a yellow label to the top.
The bottom is where the two holes are, on the side of the housing that you can see in the picture.

How was this one held in?
(Boy that thing looks like it has been through the mill a few times ...)

 

Ugh! I am seeing signs of glue around the part that would pull out ... it looks like someone has already been inside of it ...

 

After a little bit of trying, I knew there was no way of getting into the TCI without surgery. So I got out the dremel clone and carefully cut the glued area at the top. I could now slide a thin blade complete around the connector board, but it wouldn't come out, so, time to finish surgery and open her all the way up.

A few minutes later, you would have heard language that would have made bangers blush. There was glue all the way around the entire board and it was even partially glued to the part of the case closest to the back of the board. Of course it wasn't coming out.

The daughter board on top looks almost new. It is a completely different green and I didn't think those types of chips were around in the early '80s, were they? I don't know what the stuff is along the bottom edge of the daughter card. I almost wonder if it isn't some glue residue?

It smells burnt, no surprise there, looking at the black scorch marks on both sides of the board along the bottom. The bottom cover at the same place is melted from whatever happened inside.

At the top left, along the daughter board, the last 4 pins have some glue on them from being glued in. That wouldn't cause a problem, would it? Would the glue possibly be conductive?

On the back side, you can see the glue residue going all the way around. It is also on the front, right next to the daughter board outside edges.

Also on the back, if you look at the green and tan pair of transistors, at the top it looks like the solder itself is run together and not just the coating they put on there.

I can make a new box for the thing no problem, but I am wondering, does this even look like it is worth trying? I don't seen anything that would lend itself to a cold solder joint, they all look sealed by that grey stuff. What I can't see is the stuff under the daughter card, but the solder points on the back all look good.

 

The glue is normal, and so is the look. Are those 2 transistors on the heatsink burnt? Hard to tell in the pic.

Spotting bad solder joints is a learned skill, do you have anything to magnify with?

 

http://www.jetav8r.com/Vision/IgnitionFAQ.html

 

Those transistors do not look good at all. Get a magnifying glass and clean up those things on both sides of the board! Have a good look at them. I would be inclined to replace them.