'82 Celica Supra dies "randomly" - Page 2

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  1. #11
    CelicaSupra.com Member drjim's Avatar
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    Ah HAH....six pins!

    Well, that rules out its being a transistor. It's probably what's called a "hybrid", and that means (usually) unobtainium as they were generally designed for a specific application.

    And I just looked up the package dimensions for the TO-3, and compared them to your measurements, and Ray is correct...the D626 part is in a TO-3 case.

    I prefer the silicone pads. The ceramic ones have fallen out of favor with the introduction of the silicone pads, and are generally used for their high voltage capabilities.

    You probably don't have enough room for the TO-3 heatsink, and you'd have to cut the fins way down. Since these rely on convection cooling to work properly, and your devices are in a small enclosed box, I doubt it it would help any. They're typically used where the device is in "free air", like mounted on a circuit board or a chassis where the air can circulate around them and carry the heat away.

    If you have digital multimeter, you can check the D626 to see if it's shorted, the usual failure mode of a transistor.

    Lots of tutorials and videos on the web about how to test them....
    1985 5-speed "Ms. Swan"

    OH, What A Feeling!

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  3. #12
    CelicaSupra.com Member drjim's Avatar
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    Since they both have logos on them, I'm going through my books looking for the companies that made them.

    The D626 has a Sanyo logo on it, but I haven't found the other logo let. It almost looks like an old Fairchild logo, but I might be wrong about that.....

    The good new is that it's a Fujitsu Semiconductor logo.

    Bad news is that all the make now are computer products, like memory chips.

    That part is now certified unobtainium. Let's hope that the transistor is popped, and then replacements you have on order will fix it.....
    Last edited by drjim; 10-30-2016 at 10:35 PM.
    1985 5-speed "Ms. Swan"

    OH, What A Feeling!

  4. #13
    Thanks for helping me look. Earlier this evening, I sent out an email (with the above pictures attached) to a company dealing in surplus electronics. Hopefully that pans out. I'll keep looking elsewhere and sending emails.

    If the EXT180 has six pins, is it possible that it's just a "hybrid" of three transistors? It maybe a dumb question, just thought I'd ask. I mean, how complex does a device have to be in order to accomplish the relatively simple task of firing a coil?

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  6. #14
    CelicaSupra.com Member drjim's Avatar
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    More complex than you might think....

    No, they never put three transistors in a package like that that I've ever seen. They'd use three separate ones.
    1985 5-speed "Ms. Swan"

    OH, What A Feeling!

  7. #15
    Well, worst case scenario is I'll just put a new silicone insulator on the old one and solder it back on. Hopefully that will help, since it was working when I pulled it off the car. I just need to keep it from overheating.

    Would cutting it open make it obvious what it is? Surely somebody has a burnt up '82 ignitor we could dissect.

  8. #16
    CelicaSupra.com Member drjim's Avatar
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    I wouldn't cut anything open unless I knew it was bad beyond a shadow of a doubt. If it turns out that the D626 is the bad part, there might be a bunch of dead ignitors out there that people could repair.

    I have a pretty good idea what's in there as far as what the assemblies look like. I used to help fabricate microwave hybrids and before that power semiconductor hybrids.

    In the one below, I can see four transistors, some ceramic chip capacitors, and a bunch of other discrete parts.



    This one is in a square package, but they're a bunch of discrete parts soldered/bonded/epoxied onto a substrate, and connected with either circuit traces or "bond wires", and then connected to the pins that bring in signals and power.
    1985 5-speed "Ms. Swan"

    OH, What A Feeling!

  9. #17
    That's pretty interesting stuff. I'm learning something new every day from this thread alone!

    I wasn't suggesting cutting open mine, since it still (for the most part) works. I don't know much about these sorts of things, but I thought if seeing the insides would help identify it or facilitate reverse engineering it, it would be worth scrounging up an already failed '82 ignitor to cut open. Since ignitor failure in these cars is common, I figure finding a dead ignitor shouldn't be too difficult.

    Hopefully we can find a suitable off-the-shelf replacement, and none of the above will be necessary.

  10. #18
    CelicaSupra.com Member
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    Sometimes I wish I knew which fucking egomaniac "discovered" Unobtanium. Chemical symbol "Fu". I'd introduce them to whoever invented the ball peen hammer.
    In this case as well as many others, "hybrid" components are specialized proprietary components that precede the development of a family of generic large scale integrated circuits. They're the prototypes put into production that prove a concept and are later developed into single chip, or close to it systems. So these hybrids typically incorporate some serious intellectual knowledge and generally have all identifying markings removed. It's unusual for this one to still have them. But none of us were able to find any reference to it anyway because this type of "component" is virtually never available to mere mortals and usually at some point, isn't available to anyone at any price. So there's no generic replacements and never were. The only replacements are the exact part only made for a limited time by one company for usually one manufacturer. Oh whoa is us.
    This is a somewhat simple hybrid which likely has only one function. That would be to control the coils dwell time to optimize output while minimizing internal heating over the operating range. This design was used for a very short time. Before this, early electronic ignitions were basically just a transistorized switch. Early systems still used a set of points, generally without a condenser as a low powered switch for the transistor which replaced the points function of high power switch to the coil. Dwell was still a fixed amount of engine rotation which of course meant that as RPM increases, coil recharge time decreases proportionally. Not an ideal situation.
    This generation of ignition varies dwell time in the then new pulse type coils to better optimize coil charge time vs RPM. Ignition performance significantly improved.
    In our case, 83 Toyota TCCS systems replaced the mechanical and vacuum ignition timing components with an igniter that also could control timing based on ECU commands further improving performance.
    So hopefully and likely only the high powered switch is beginning to fail. Amazingly it's still available. There just has to be a reason why. Toyota certainly wasn't the only manufacturer that used this type of system. In fact, my statement that they only did for a short time is really only true on our cars. It was used for quite a few more years on lower line vehicles like pickups, Celica's, Tercels, etc and the same is true for other manufacturers. This transistor is not a general purpose replacement. It's application is very specific for this use only as are its characteristics. So Dr. Morse predicts a cheap and successful repair in your future provided this is your problem. However, your electrical nightmare is going to need some serious attention based on your description of what you've discovered.
    Besides replacing your rats nest harness, there's also a fusible link wiring change that was recommended for just about every Toyota from the 70's into the 90's to lessen fuse box heat by routing charge current directly to the battery and adding a separate fusible link and power feed for the fusebox directly from the battery.

  11. #19
    CelicaSupra.com Member ddd228's Avatar
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    ray85p and drjim are the first places to try for OLD component repair ideas.
    THOSE are great photos,BTW.
    We may have a possible solution for those pesky igniters,if we get lucky.
    The heat sink compound is the first choice only if it can reduce the overheating issues/heat soak.
    I yanked my SPARE unit out of my L.R. cubby and re did the compound to ensure that my replacement unit would function until I found a replacement.

    It's back in it's place while the OEM unit is still functional.
    The extreme fear is that the replacement one that I use as a back-up will fail in a week due to overheating issues.Car dead. No fun.
    The unit that you have photographed so well is a LOT different than the '84-'86 units.

    I hope that this thread will help a few of us out!



    Maybe the old school units will be less problematic from here.
    Dave in Seattle. I keep LATE hours.Hidden Content
    '84 type "L" ,Auto ,daily driver. Dk blue.

  12. #20
    Well, I snatched up another ignitor for $100 on ebay this morning. Guy said it was "pulled off a car with a bad motor", so I hope it wasn't actually a bad ignitor. It's a gamble, but hopefully it will get my car running again temporarily until I can repair/refurbish my current one.

    I'd still be interested in buying another one, if somebody has a spare they'd be willing to part with. It seems you can't have too many spare ignitors for a MKII Supra.

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