Repairing Trackpoint with torn cellophane ribbon?

[soyabean]

As you know, underneath your keyboard is usually a myrad of two or three ribbon cables... why IBM doesn't have it all on 1 cable is something we'll never be able to ask and know.... *anyways* the skinny ribbon for the trackpoint is usually folded in a weird diagonal or L-shape to route properly to the mainboard... it can be torn easily, so take care when lifting up that keyboard.

My question is looking for techniques to repair torn cellophane ribbons. The Trackpoint one in particular has very very very thin lines... using a silver conductive pen will require some [censored] skill... I was wondering if anyone can share repair ideas and techniques.

[Weanuts]

Just repaired my 2611-451 Trac P ribbon (3/16" wide by 6 strands) by soldering fine wires strands to each trace and expoxed the open wounds. Less flexible but I have a trac point again. It is possible but vvvvery delicate.

[Kyocera]

Weanuts, you could be a surgeon, I tried that years ago and finally gave up

[soyabean]

I would love to see a pic (a flatbed scan) of the repair! I don't even know where to begin. I was considering popping open the trackpoint and soldering wires directly onto the trackpoint, and then running them long enough to the fattest part of the cellophane ribbon, just where it meets the motherboard. Or, cut the ribbon diagonally, so when I solder the 6 lines, they are spaced as much as possible.

[Weanuts]

As you know they are delicate, less played with less problems. When I have to open the pad up again I will photo it and be back to you and forum. Split traces, solder 1, tape off, solder two, tape off and so on. I expoxed and then proceded to carry out procedure at oposite end of patch and then expoxed all together. Wire patch is .007"

[tfflivemb2]

Yeah, I'd love to see it too. I have two broken trackpoint cables on two different i1400 keyboards. I'd love to be able to fix it instead of buying another one.

[Weanuts]

A pic is worth a thousand words so they say, but, seeing is believing. I can't prove to anybody that what I am saying or doing works. I am in process of repairing another trac point and will snap pics of this and ship different points by picture to anybody that wants. Understand this though, it is not for anybody with shakes and a very good magnifier is a must. I am using a small wattage soldering pencil and it has been ground down to a fine point. I repair one trace at a time and turn off pencil to save point. I test end of joint with low impedance ommeter, before covering with epoxy. This practice of soldering is the same as repairing, or replacing parts on boards of any type. It is though a lot tighter in proxsimity to board work.

regards

[soyabean]

We are not asking for proof of repair - I am merely looking for ideas and techniques, and I'll be able to extrapolate that from seeing other's repair jobs. I consider myself an experieced solderer for anything that doesn't require a fine tip, but surface mount and cooper wires are something usually left to robots. The cellophane ribbon I have to fix is on a i-series, which is something I don't see often. I got one shot because I know there are no spare parts. They are outnumbered by A and T series almost 20:1.

[Weanuts]

Sorry I took so long to get back. Getting over heart attack. No pics. The method i used was to have a good magnifier, a fine tip low wattage iron lots of rosin, fine rosin core solder, and some 400 grit sandpaper or finer. Very carefully sand the the film off of 1 side of ribbon for approximately 1/64" or less to expose copper buss 6 strands on 1 end. On the other I exposed the same amount on both sides. Rosin all joints, and only enough solder to tin not blob. You are painting gently. Very carefully tin or solder exposed strands by lightly stroking strands. do both sides of mated surfaces to be. Bend mobile piece of ribbon gently to apply slight pressure to overlap fixed ribbon and tape in place over fixed ribbon a few thousands of an inch. The trick is to stroke or dab in this operation. I mentioned earlier to use ohmmeter to test, be careful, be careful, be careful, as I may have damaged the circuitry on this puter key board track ball hammer three #10L1171 or actual keyboard #02k4737 itself. So now I am looking for these parts. Do not use ohmmeter to test from 1 leg to another, only to test continuity between joint and end of that leg and that leg only. This practice is a gamble at best. Good luck to anybody who tries. Remember the ohmeter practice please. If you have an old ribbon practice on it first.

Regards

[Kyocera]

Dang, weanuts, sorry to hear about that....but glad you made it through that OK.. I think anyone that can solder a ribbon cable back together can make it through anything.

[tfflivemb2]

Hey Weanuts, sorry to hear about the heart attack. Concentrate on getting better, don't worry about the pics now.

[joester]

The fact that this post hasn't been updated in a year makes me wonder how Weanuts made out. Hopefully well.

It appears, however, that I may be taking up his torch and repairing a ribbon cable using his method. I'll take pics as best I can and post.

BTW: If anyone has a "dead" keyboard or two they can spare, I may be talked into refining the method and repairing a keyboard for the donor for a very nominal fee.

PM me.

Joe