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The guide to Gen1 ignition boxes and how to fix them

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The guide to Gen1 ignition boxes and how to fix them

PostAuthor: nanno » Tue Jan 28, 2020 5:12 am

... yourself.

Simple mission, big proposal. But, I wouldn't post this, if I hadn't already managed the bigger tasks.

For a first post, here's the parts-list and yes, I've found a substitute for the transistor, which is a hardened type for automotive use. As far as the electrolytic caps go, if you really have to replace them, go with hardened ones for automotive as well, as they will then be rated to 125°C instead of 85°C and use name brand components unless you fancy doing the same job again in one or two years. That being said, if the caps are ok, leave them alone. Most likely you will find (at least one) cold solder joint. (seven or eight in my case)

Main Transistors (2)
2 x 1D1 ETD51-030 -> substitute BU941ZT

Logic ICs (10)
3x TC4001BP (NAND Gate, 4 gates, 2 input, 1 output)
3x TC4011BP (NOR Gate, 4 gates, 2 input, 1 output)
4x UPC451C (Quad-op-amp)

Electrolytic Capacitors (12)
9 x 1.0μF 50v
2 x 0.22μF 50v
1 x 4.7μF 50v

Ceramic Capacitors (23)
8 x 102 (1000 pF)
5 x 103 (10000pF)
7 x 223 (22000pF)
2 x 472K (4700pF)
1 x 473M (47000pF)

Epoxy Capacitors (6)
3 x 104K (100000pF)
2 x 153K (15000pF)
1 x 103k (10000pF)

Also, if you can't or don't want to wait for the subsequent posts, please follow these four links and you'll see what I've been up to.

https://greasygreg.blogspot.com/2020/01 ... ntals.html

https://greasygreg.blogspot.com/2020/01 ... board.html

https://greasygreg.blogspot.com/2020/01 ... -both.html

https://greasygreg.blogspot.com/2020/01 ... t-for.html

Post #5 is to follow as soon as I am well enough to get out to the shop as I want to do some in-depth research on the waveforms on the coils with the oscilloscope, because believing that everything is fine is a vastly different animal to proving everything is fine.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

*Look to my profile for a link to my blog*
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nanno
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Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
1984 XT500 4Valve (Austrian Tax saving edition)
1979 RD250/R5/DS7-hodgepodge (in bits)
Sex: Male

Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: nanno » Tue Jan 28, 2020 10:44 am

Please bear in mind that the availability of some of the ignitions might be somewhat euro-centric, but that's where I live and then again there's also some other Europeans reading this. So let's do it as in any good academic paper and giver ourselves an overview on the area of research and it's limitations, which in this case means I will only work on ignitions which came with the double pickups. Why? Well, that's what I have and what I have engines to test with.

1) The standard metal cased one as you see above, stamped J4T00671 or J4T00672 (I haven't worked out the difference yet, but 671 was only available in 1981 and for 1982 to 1984 672 was available.)

Image

2) and secondly and I hadn't been fully aware of this box for quite a while, on the so called Midnight Special models and very early XV750 and XV1000 twin-shock models, so from 1984 to 1986-1987, there was a second ignition box, marked 20x-20 J4T00871.(This box was kindly donated by a TR1-Forum-member as his bike only ran on one cylinder with it.)

Image

Let's first have a short glimpse on the Gen1 box'es internals, which are (to put it mildly) a bit messy. (Don't worry the subsequent posts will give you a sort of a roadmap of what you're looking at.) Also I took the liberty of taking these photos in max. resolution of my camera, so you can zoom in and snoop around to your heart's content. (There's some other posts on this forum, but even cell-phone cameras came a very long way in the last three or four years...)

Image

Unless you noticed it yourself, the second Gen box looks a lot neater and this is, what was generally referred to as the micro-chip revolution of the 1980ies. (Both boxes at the time of their design were absolutely at the height of technology and it's only been two or three years between them. And what took two boards on the older version is now done in the two small Mitsubishi M59201P chips at the top of the picture. Also note the switch to much more efficient transistors and just how small the heatsinks are on the plastic-box version.)

Image

That being said, as I will outline here, you can also use the 2nd Gen box on earlier bikes, but you will need to make an adaptor-loom to run it on your early Gen1 bike. The added bonus being, these boxes are still available new for around 60USD.

This is essentially, what is covered in this blog-post: https://greasygreg.blogspot.com/2020/01 ... ntals.html
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

*Look to my profile for a link to my blog*
User avatar
nanno
Silver Membership
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Posts: 1418
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Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
1984 XT500 4Valve (Austrian Tax saving edition)
1979 RD250/R5/DS7-hodgepodge (in bits)
Sex: Male

Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: nanno » Tue Jan 28, 2020 10:53 am

Prying the 2nd Gen box open is relatively simple, the metal-box TCI is a bit more tricky, especially when you really want to lay out the boards in front of you.

1) lift the tabs

Image

2) On both of my boxes the rubber pad on the back was slightly stuck to the metal enclosure and a bit of gentle prying was necessary to get it off.

Image

3) The board is held in with 4 clearly visible screws straight through the board and two holding on the heat sink that go in from the outside

Image

4) The conformal coating resin also affixed the heat sink to the case - not sure if that was intentional

Image

... but it only takes some mild persuasion (and I checked, the box is still functional) :bg:

Image

5) If you want to split the boards, e.g. because you want to replace the electrolytic caps, you will find retaining tabs poking through the daughterboard on the top. I marked them in red as some of them are a bit hard to distinguish from solder, when covered by resin. Don't make my mistake and remove them from the main board as they will be MUCH harder to get back in place, when it is time to reassemble.

Image

This is what the second link was more or less about: https://greasygreg.blogspot.com/2020/01 ... board.html
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

*Look to my profile for a link to my blog*
User avatar
nanno
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Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
1984 XT500 4Valve (Austrian Tax saving edition)
1979 RD250/R5/DS7-hodgepodge (in bits)
Sex: Male

Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: Mace_Hacker » Sat Feb 20, 2021 1:34 am

I am working on mine this weekend. Thanks you for the parts list. Good information!
Love your country. Fear your government.
I have an '82 XV 750 and a ‘92 XV1100
It’s ok....It’s supposed to sound like that!
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Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: Mace_Hacker » Sat Feb 20, 2021 11:46 am

nanno, I have a question for you.
In your research did you find mention of ST901T transistor bein used in Yamaha TCI's and if so how does it compare to the BU941ZT ?
I don't know enough about electronics to fairly compare them.
Love your country. Fear your government.
I have an '82 XV 750 and a ‘92 XV1100
It’s ok....It’s supposed to sound like that!
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Mace_Hacker
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Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: nanno » Sun Feb 21, 2021 3:39 am

Hi Kenny,

I'd rather respond here, so more people can benefit from the answer, if you don't mind. Main differences are a) BU941ZT allows to switch higher currents (should result in more longevity) and b) it has got a marginally different (I think quicker) switching behavior. In essence it should make no difference.

Cheers,
Greg
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

*Look to my profile for a link to my blog*
User avatar
nanno
Silver Membership
Silver Membership
 
Posts: 1418
Images: 1
Joined: Thu May 26, 2011 4:06 pm
  Flag
Bike year & model: 1981 Yamaha TR1
1982 Yamaha TR1 Turbo
1977 XS 750 Sidecar
1984 XT500 4Valve (Austrian Tax saving edition)
1979 RD250/R5/DS7-hodgepodge (in bits)
Sex: Male

Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: Mace_Hacker » Sun Feb 21, 2021 10:45 am

Greg,
That works for me! I understand electronics well enough so that makes perfect sense...lol.
Looking around for information on how to work on these, I only found a very few pages that went in to any depth.
What I am doing is taking pictures and video as I go. I will post the video, when complete, on youtube.
My goal is not only to fix my TCI's but, I want to use my project as an opportunity to make a PCB template and eventually a schematic, for others to use in the future.
If I had a new PCB I would much rather just order all the new components and put that together that go through the pain of cleaning the glue off the old one!
You listed the IC's in your parts list and I was curious to know if you found a good source for them? If I remember correctly when I looked, one was not available, so if you have a source for all of them that would be good information too.

EDIT: I looked on Mouser for the IC's and they do not stock them. 2 were listed as obsolete (TC4001BP,TC4011BP) and 1 was not stocked ( UPC451C)...but might be orderable.
I did find them on other sites but I am not sure of the reliability of getting a genuine part. Any input on trustworthy sources would be good.


Lastly, I am going to replace the diodes and small transistors as well as anything else that is not a resistor. That is my plan anyway. I know basic component testing and identification so I will be asking for help on some things I am certain.
Exampe: Diodes - I can read markings and measure ohms but how do I determine voltage rating?
Resistors - Again, I can read ring color markings and determine value but how do you figure out watt? ( 1/4, 1/2, ect) and.....would 5-10% tolerance be fine on those if I did replace them?
Those would probably be my biggest problem points.
When I get the boards clean completely and the parts removed I am going to replace; I will make a parts list, like yours, but I will also add a source list for where I got them. I plan to use Mouser so I will probably just use that order sheet.
Thank you again for all your work and information!
Cheers,
Kenny
Love your country. Fear your government.
I have an '82 XV 750 and a ‘92 XV1100
It’s ok....It’s supposed to sound like that!
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Re: The guide to Gen1 ignition boxes and how to fix them

PostAuthor: Mace_Hacker » Fri Feb 26, 2021 11:33 am

Update: I am working on rebuilding my TCI.
This sucks.
I know all the Caps need to go but I wanted to check the diodes. I measured all of them, in circuit. This did not yield good news. So I started taking them out so I could measure them out of circuit and test them with my cheap component testor.
Well, I got different readings out of circuit which indicated that maybe the diodes might be ok? I don't know yet. Looks like I am going to 'have' to take each one loose at least on one leg to test out of circuit and find out.
I also reached out to YAMAHA Corporate to see if it might be possible to get an actual schematic. Not holding my breath on this though.
Sample of readings I got is on picture below. The yellow marking indicate readings I took on them out of circuit. One shows OL/OL and when I tested it for continuity I did not get any. So......
I will keep going. I am not an electrical engineer and barely know what I am doing...lol I do have patience and determination though.
The hardest parts for me will be, if I have to replace any or all of the diodes.....I don't know how to determine the type and value.
That's it for today's update; Stay safe.
Mace

EDIT: NOTE - The values on the two yellow notes below are not exact----but I know they were close to that...I walked off and left my notes and paperwork at home so I just plugged in those numbers as an example. Main point is, I got readings one way and O.L the other way.
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Love your country. Fear your government.
I have an '82 XV 750 and a ‘92 XV1100
It’s ok....It’s supposed to sound like that!
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Mace_Hacker
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Posts: 75
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Joined: Mon Jan 05, 2009 8:14 pm
Location: Charlotte, North Carolina Flag
Bike year & model: 1982 xv750
Sex: Male



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