does it sound like my TCI is bad?

[DAVINCI]

Oscilloscopes? Octopus? Guys, these things are not that sophisticated. For the 2H-10 model, 99% of the components are available, it's a matter of being willing to troubleshoot them at the board level without a schematic. The upside-down configuration makes it time consuming. For the 81-up models, however, some of the components are unobtainium.

And, it's NOT a business, it's a helping hand to the membership, I just want something for my time, the $20-$25 I've charged over the past 4-5 years was only initiated because of the volume of work I was getting combined with the condition of the 'patients' I was seeing.

Some of you veteran members may recall that 8-9 years ago I began offering this service for free. That was great, until I started getting boxes that had been chopped open, run over and de-soldered with all kinds of implements of destruction.

I put a halt to the free service when I started getting bastardized boxes with no return postage, and a note with something like 'tell me if it can be fixed'. Well, I think you can see where it was going. In fact, I have one right now in my possession I got from a member in exactly that same way. Haven't decided what to do with it yet.

Here's the scoop: 99.99999% of the problems can be corrected with re-sweating the joints as has been previously discussed. In all these years, I have only seen three units that needed one or two of the output transistors replaced. These I repaired with transplants from scrap boards. For real techs like some of you, this is easy stuff, hell, at least it's not SMD. On these puppies you can at least get an iron tip in there LOL!

If you're serious about doing this, PM me your mailing address and I will gladly send you all the spare scrap parts boards, cases, screws and covers I have left. I pass the torch to the next generation of TCI Gods.

Sure, it's cool, it's hip and it's something that needs to be done to keep the old girls going. Just don't for a minute think it's a viable business venture.

[DAVINCI]

Here's everything from my old website, HTH

Here I've complied some facts about the Yamaha Ignition TCI unit that was used on the 78-81 XS1100's.
If you have problems with your TCI and need help, before pulling out your hair, try this quick TCI test:

It's a very old shaky .mpg, so be patient! If it doesn't play well, i can e-mail it to you.





http://s307.photobucket.com/albums/n...rent=tci-1.mp4

Using a voltmeter set on 12VDC, connect the positive meter lead to the Orange or Grey coil lead at the TCI. Connect the negative meter lead to the black (negative) lead at the TCI. Turn on the ignition. Voltage should come right up to about 10 - 11VDC. Crank the ignition and observe the meter. Look for a wide voltage swing during cranking. A strong swing indicates that the pickups and TCI are working OK and your trouble is between the TCI and the plugs. Possibly a bad ballast resistor, bad coil, bad plug cap or just corroded connections. Repeat this test for both Orange and Grey coil leads.
Still have problems? - e-mail me here

rrago@nyaes.com

This document will outline the basic operational theory of the XS11 TCI or Transistor Controlled Ignition box and common repairs that can be accomplished by the home mechanic. First, a little background on ignition systems.

Basic Theory of Electromagnetic Ignition Systems This is for the youngsters
Prior to the dawn of electronic ignition control, a set of contact points were used to physically switch the ignition coil(s) on and off in time with the crankshaft rotation. The ignition coil is constructed of a primary winding that is switched by the points and a secondary winding attached to the spark plug. For most of the rotation of the crankshaft, the points remain closed, energizing the coil(s), allowing them time to build up a strong magnetic field. The energizing cycle is known as dwell time, expressed in crankshaft degrees.
Those of us (of a certain generation) who are familiar with tuning automotive engines may have used a dwell meter to fine tune ignition points during a tune-up. Setting the dwell in effect is relative to setting the point gap, although much more accurate because setting dwell is done with the engine running. Proper dwell time (or gap) is critical for the coils to reach their full potential for producing a strong spark.
When the contact points open the collapsing magnetic field inside the primary winding induces a high voltage spike in the secondary winding and we have a spark at the plug, and a fire in the hole. The large ratio between primary and secondary windings inside the coil is responsible for 12 volts becoming somewhere between 25,000 and 40,000 volts at the spark plug.

The XS TCI System

The XS11 TCI or Transistor Controlled Ignition system replaces contact points. This type of system, although much more complex, has no mechanical parts to wear and so is less prone to go out of adjustment. In addition, the quality and regularity of the spark is far superior to a points system which can arc and burn eventually reducing their ability to conduct full voltage through the primary of the coil(s).
As in a points system, in the TCI system the ignition coils are energized most of the time. Replacing contact points, a set of magnetically controlled pickup coils send a timing signal to the TCI. The signal from the pickup coils is a very low voltage and so is amplified inside the TCI and routed to a set of high power switching transistors to cut the ignition coils off, producing the spark.

Identifying the TWO types of TCI’s
The 1978 through 1980 XS11 E, F, SF, G, SG and LG used a TCI that employed a mechanical advance mechanism under the timing plate on the crankshaft. These TCI’s are labeled 2H7.



In 1981 on the H, LH and SH models the mechanical advance mechanism was deleted and the advance was programmed into the circuitry of the TCI. These TCI’s are labeled 4RO.

The 2H7 TCI label is embossed into the top cover of the unit. The 4RO units have a foil tag glued to the cover. The foil has tendency to fall off, so if your TCI has no number on it, you can be fairly sure that it’s a 4RO.
4RO 2H7


Under the Covers
A look inside can verify the type of TCI. If you are unsure of the type you have, remove the six screws holding the cover and compare it to the photos below. You can see the differences between the two types by the pin layout of the output transistors at the top of the board. The 4RO uses small (TO-220) case transistors and the 2H7 uses large (TO-3) transistors.
The foil side of the board
4RO 2H7

Note the two horizontal rows of pins in the center - right of the 4RO board. This is the 16-pin advance IC.



A look at the business side of the boards shows the differences even better.

The component side of the board
4RO 2H7



Here you can also see the pin functions:

P1, P2: Pickup 1 & 2 positive (P1 is coil 1&4, P2 is coil 2 & 3).
P1-, P2-: Pickup 1 & 2 negative.
E: Earth (frame ground).
B: Battery +12v.
SW: Emergency Stop (tip-over) switch
R: To Ballast Resistor (2H7 only).
ST: Starter Solenoid for full +12 during cranking (2H7 only).
C1, C2: Coil1 (1&4) and Coil 2 (2&3)

Update - 2H7 Type 2 TCI
Recently discovered is the 2H7 Type 2 TCI. This seems to be a transitional type that incorporate the smaller TO-220 case transistors instead of the earlier TO-3 . These TCI’s are labeled 2H7 and operationally are identical to the 2H7 used on 1978 through 1980 XS11 E, F, SF, G, SG and LG, using the mechanical advance mechanism.



Common Symptoms of TCI Failure and Can I Repair It?

The most common symptom of TCI failure is a sudden loss of one half of the system, either the 1-4 or the 2-3 cylinder sets losing spark. Less common is a complete ignition failure. After troubleshooting the easy parts: fuses, pickups, ignition coils, plugs, plug caps, ballast resistor, tip-over switch and stop switch you are left with digging into the TCI. As daunting as it may seem, the TCI is repairable and the good news is that most often the repair is a simple one. If you’ve ever successfully used a soldering iron, you can repair 90% of TCI failures.

The most common point of failure is the solder joints between the connector plugs and the pc board.

Using a small (30watts or less) soldering iron and thin gauge 60/40 rosin core solder, re-heat each pin and apply a small amount of new solder. Be careful not to apply so much solder that you bridge between pins. When finished, inspect the joints for cleanliness and color. Good joints will be shiny and clean. Poorly set (cold) joints will look dull and flaky. Repeat as necessary.




Replace the cover making sure the rubber gasket is in place. One final check before re-installing the TCI – turn it over and see if it’s been sealed. Some units have a factory seal in the bottom, some don’t. If yours is open, seal it with some silicone to prevent moisture ingress. This will reduce the need for another repair in the near future.




If this fix does not cure your problem and you still need need help,
e-mail me here

rrago@nyaes.com

[DAVINCI]

Photobucket blows

Not sure why some pics posted and some didn't, but since I can't edit the post any more, I'll try to fill in the pics that didn't make it the first time:

Under the covers:




component side of the boards:

[DAVINCI]

For you experimenters out there..

Take a close look at the last photo there of the 4RO TCI. Notice the place-holders on the board for R22 and R24? I'm fairly certain that these potentiometers were intended to be used for adjustable timing curve / dwell settings. As for the intended resistance value, it's anyone's guess. But, if you're into fiddling with stuff like that, the 4RO box is the one for you!

They're kind of hard to find, though

[natemoen]

Tech tip info!!!!!

[DAVINCI]

Sorry..forgot to mention...

The output transistors, which are the most likely part to fail, are NPN Darlingtons.

[mikubuilder]

Man, Randy, that's exactly the info I was searching for a while now....everyone was pointing to you, but looks like you were busy with repairing all those boards
and $20 or $30 you were charging for those fixes was not even close to a price of a good unit, so don't feel bad, your time has value, too....
I am not an electronics guy by any means, but I've been taking things apart and fixing them since I was 10 yrs old, I like to know how things work(that's partly why I got this old girl to play with )
I hope you don't mind and mods would be allowed to put this info in repair section....

[crazy steve]

...I hope you don't mind and mods would be allowed to put this info in repair section....

Already saved to 'tips under construction', I just need to find the time to edit it down....

[DAVINCI]

As I wrote..i don't mind AT ALL! Take it....run with it! In fact, for years I had all of this posted on the web, but I lost my ISP and web page when I got divorced and moved out of PA. Then I lost interest in creating another web page. When ever someone here asked, I offered the answers, but this way it's better. Maybe a new breed of TCI Techs will grow out of this. So here it all is for the use of the site as you guys need it.

I started to gather this info back in '91 when I got my first XS ( an '81 Special) and the TCI quit on me like a week before Americade. Back then, pre-Ebay, I had to either cancel my trip or get a TCI from a bone yard. I opted for the bone yard and luckily it worked. Don't ask me how much I paid for it then, I'm embarrassed to reveal it!

So after I got the bike running again, I tore into my old one (4RO) and figured out the circuitry, fixed it and wound up with a good spare. I was a happy camper. Then when I started my 2H7 restoration and stumbled upon this site in '02-'03, someone asked the question and I said 'Sure, they can be fixed..send it to me..'...the rest as they say, is history.

To this day, even though I'm good at fixing these, I always carry my good spare 2H7 on long trips, ya never know

So, here ya go, it's not rocket science. Gentlemen, unholster your irons and go to work

[natemoen]

unholster your irons and go to work

My iron died in me. The other week I pulled it out to put some new bits on an amp board and it dint work. Didn't want to go but a new one so I ended up using a stainless solid wire and a torch. Surprisingly it actually worked!

[DAVINCI]

Of course!

I remember learning to solder in shop class. We had bunsen burner ovens and you stuck the iron in it and waited. used the same irons in metal shop and electric shop lol!