Yet ANOTHER Pamco troubleshooting scenario Indepth

Terrible1

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1980 XS650 with
PMA (HHB)
Pamco Original conversion
Dynatek DC1-3 Coil
Yuasa YTX12-BS Battery

Bike has ran just fine for a full season, just went to take it out and no spark. Here's what I've gathered from troubleshooting and checking everything over the last 2 days.

Battery 12.4 VDC

Coil
Primary resistance 3.2 OHMs
Secondary resistance 15k OHMs
Primary to Center core OPEN
Primary to Plug wire OPEN
Plug wire to Center core OPEN

Pamco Voltages
Red 12.4 VDC
Black 0 VDC
Green 12.4 VDC (Note this varies down to 1.12VDC when the plate is spun around)

I have checked the individual component on the Pamco plate

resistors are
500 OHM
800 OHM
8.1k OHM

the PNP Transistor GB14C40L is where I am running into issues. While using a Fluke 189 Meter in Diode mode I get the following:

+POS Base to -NEG Emitter Open Line (Good)
+POS Base to -NEG Collector Open Line (Good)

-NEG Base to +POS Emitter 1.11VDC (Good is .45VDC-.9VDC) Problem
-NEG Base to +POS Collector 0VDC (Good is ,45VDC-.9VDC) Problem

Collector to Emitter .45VDC (Good is Open Line) Problem

From what I have found online and here on the board I believe that my transistor is bad. Can anyone confirm this from the troubleshooting? http://www.vetco.net/blog/?p=184 is the link I used for the pin out of the transistor. I am testing the transistor in the circuit and am wondering if that has any issue.

I have verified that the VDC at the coil +POS is 12.4 and that the signal from the PAMCO Green wire (12.4 VDC until I spin it then it will drop to 1.11 VDC. When I spin the plate and ground a spark plug to the engine case I do not get any spark, but I do hear a clicking at the coil. This somewhat confuses me. From what Im gathering is that the if the transistor is actually bad that the signal that it is sending to the green wire to the coil is the incorrect signal to "FIRE" the coil.

Any one care to chime in?
 
For Cross referencing and informational purposes i have linked this to the Pamco Thread.............HERE

And i will link the Pamco thread to this thread as well........................kinda makes me wounder why i went to the trouble of making up a thread like that..........A post like this would have made a good addition to that thread................
 
I spent about 2-3 hours going over everything in that thread and about 15 others across the Internet. I didn't know that the thread was for posting problems individuals are having as I thought it was more of an informational and how to thread.

Maybe I should change the thread title to can anyone confirm what I've spent the last 3 days troubleshooting.
 
...Pamco Original conversion

Collector to Emitter .45VDC (Good is Open Line) Problem

From what I have found online and here on the board I believe that my transistor is bad. Can anyone confirm this from the troubleshooting? http://www.vetco.net/blog/?p=184 is the link I used for the pin out of the transistor. I am testing the transistor in the circuit and am wondering if that has any issue.

You're not testing a typical transistor. In-circuit testing is always conditional. But, in your Collector/Emitter test, first ground the Gate and Emitter, leaving the Collector open.

GB14C40L.jpg
 
Thank you for the reply TwoMany. I have checked out a few other things and while the IGBT is still in the circuit I am able to ground the gate and then test the collector to emitter and I do get the correct reading of Open Line. As soon as I take the ground off the Gate it reverts to approximately 1 VDC.

Shouldn't this remain an Open Line until the Gate is recharged by a VDC?
 
... the IGBT is still in the circuit ...
...take the ground off the Gate it reverts to approximately 1 VDC.

Shouldn't this remain an Open Line until the Gate is recharged by a VDC?

Hard to say, what with MOS sensitivity to floating inputs. There *could* be a failure in the Collector->Gate clamp, or there may be some sort of external circuitry that allows Collector voltage to creep to the Gate. I'd have to see the entire circuit, and see what drives the Gate...
 
Your test has the green wire to the coil going from 12 Volts to about 1 Volts. You can hear a click in the coil. If the green wire is going from 12 to 1 Volts as you rotate the rotor, then all is well with the PAMCO. The IGBT transistor is working properly or it could not pull the coil down to 1 Volts. Conventional PNP transistor tests with the IGBT transistor are meaningless. I would suggest a bad coil or open wires to the spark plugs. The spark plugs in a dual output coil are effectively in series so if just one of the spark plugs or wires is open, the spark on that side will not be there and the spark on the other wire / spark plug will be greatly diminished.

 
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Your test has the green wire to the coil going from 12 Volts to about 1 Volts. You can hear a click in the coil. If the green wire is going from 12 to 1 Volts as you rotate the rotor, then all is well with the PAMCO. The IGBT transistor is working properly or it could not pull the coil down to 1 Volts. Conventional PNP transistor tests with the IGBT transistor are meaningless. I would suggest a bad coil or open wires to the spark plugs. The spark plugs in a dual output coil are effectively in series so if just one of the spark plugs or wires is open, the spark on that side will not be there and the spark on the other wire / spark plug will be greatly diminished.


Thank you for this information. I have confirmed that the green wire is still going from 12VDC to 1VDC and upon inspection of the coil and removal from the bike I have noticed some small bulging and I believe that the center core has shorted open or let go from itself. I did not notice the bulge when I originally checked the coil out, so I will be ordering a new one and testing.

Again, thank you for your time and knowledge PamcoPete.
 
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