Troller dual power pack

[sd75i]

  Only thing illuminated on panel was on off light.  Didn't have momentum lights on and brake switch springs back.

[mmagliaro]

Hmmmm it looks to me now like the two red wires coming off the transformer go under that board (the one with
the throttle circuit on it, with the 4 connectors that are on the back panel).  I'm just guessing, but they probably go to a bridge rectifier.

(I'm guessing that the other transformer secondary is used for the accessory power, but the two throttle circuits
are sharing the same secondary).

Any chance you can get under that board?  Or unhook the 4 back-panel connectors, but leave all the wiring intact, so you can flip that board over to show what's under there?   If the two heavy red wires from the transformer go to that board, then
check for AC voltage across the 2 red wires.  See if you've got something like 16 VAC there.  If they go to a bridge rectifier,
it wouldn't hurt to check the DC side of the rectifier to make sure you've got something like 12-16 V DC there.

And I'd still unhook one end of those glass bulbs and check them with an ohmmeter.  Those readings you got before were very strange.

These are the basics.  I'm just trying to confirm that the fuse bulbs aren't blown and you've got voltage going to that board.

Now I see the two power transistors screwed to the metal heat sinks right in the middle.  If we can get past the basic voltage and fuse checks, that's where I would check next.  Any chance you can get a number off those?  I would want to hook a voltmeter between ground and the transistor's base terminal, and see if that is rising and falling as you turn the throttle up and down.

[peteski]

This is not going to be easy with just taking photos.  There is lots of components and a wire spaghetti. 

I had a different thought from Max: the red wires coming out of the transformer look like they are for the primary 120V AC winding. Can you trace them and see if they connect to the power cord, or to the power switch (or a fuse if there is one)?

If you look at the dark side of the moon transformer (the opposite side than the one with 2 yellow and 2 red wires), how many wires come out of the transformer, what color are they and where do the connect on the other end?

[mmagliaro]

Agreed, this will be hard from photos. 
And yes, if you could trace where all the wires coming out of that transformer actually go, it would help a lot.
Just knowing which colors go to the power cord, the power switch, and the circuit board would be a big help.

The 120v line seems to come in right down the middle, hook to the power switch and pilot light, and then black wires trail off from there to the underside of the transformer.   Also, one red is connected to the side of the transformer we see with a bundle of yellow wires.  That's why I don't think it's the primary.   

It would be good to get some more, closer, well-lit, sharply focussed photos.
With all the photos you've posted, it still seems like everywhere I look, the thing I need to see is either blurred, or too dark,
or not in the picture.   Can you get a number off those transistors on the heat sink?  Are they TIP 21's ?

[sd75i]

Head spinning Head spinning Head spinning

[sd75i]

  I apologize but what part do you want the number off of?  Is it the square box thing with the fruit roll up wrap around it?  As far as the bulb thing, do I need to unsolder one of the wires?   I know you guys can help and I will try to do whatever you are asking.  I hope you can have patience with my inexperience and work schedule!

[mmagliaro]

Part number off this (circled):


On the glass bulbs... yes, since you were getting weird readings, unsolder one lead on each one, and then measure the resistance of them.  It should be zero (a dead short).

And tell us where all the wires from the transformer are going... as in:
"One black from transformer to power cord, other black from transformer to switch,  one red from transformer to circuit board..." and so on.

-----
Sorry to ask for so much, but the insides of that thing are messy and this is hard without a schematic or more close-up photos.
If it were sitting here in front of me, I could probably poke around in there with a meter and figure it out in a half-hour, but this remote control idea isn't turning out as easy as I thought it would be.   

[peteski]

  I apologize but what part do you want the number off of?  Is it the square box thing with the fruit roll up wrap

Just to be clear, this is a transformer:

It is not exactly like the one in your throttle, but you can match the general shape. 

[Carolina Northern]

Max,

From reply 14 -  The original transistor is a BDX53B

Don

[mmagliaro]

Thanks, Don.  I didn't see that.

Okay, so those are NPN power Darlingtons.  Surprisingly, that part number is still available
(although any decent high-powered NPN Darlington would probably do.

Terminals   B   C   E
Since it's NPN... I'll take a slight guess here and bet that it's just a current amplifier here, so we should
see the base voltage rise and fall as you turn the throttle speed up and down, and I would hope that if it
does, you'd see the emitter rise and fall too.

sd75i  -
Here's a little test.  See what you get if you set your meter on DC volts, hook a small load on the throttle outputs like a grain-of-wheat lamp, hook the "-" meter lead to the case, and then put the "+" lead on the
"B" (Base )of the transistor shown in the photo below.
Note: I don't know which transistor is for which throttle side, so you'll have to try both.

Turn all the momentum and braking off.    Turn the throttle up and down and see if
the voltage on the base of that transistor rises and falls.  Then do the same on the "E" (emitter).

If the Base voltage is rising and falling, that would tell me that most likely all the rest of the throttle is good,
so if we're lucky, this will eliminate a lot of guessing.  If the Base voltage is dead, then we have to keep digging.

[Doug G.]

Um, that isn't a dual secondary transformer. There are two transformers in there, one for each throttle. You can see the second transformer in the closer up photo.

Doug

[mmagliaro]

Um, that isn't a dual secondary transformer. There are two transformers in there, one for each throttle. You can see the second transformer in the closer up photo.

Doug

Holy mackerel!  You are right!   I didn't see it behind the circuit board there.  That makes this a lot easier to understand.  Those two terminals that sd75i tested at 0.1v are probably just multiple taps off the secondary.

Okay --- STILL, turn on the throttle  take the readings on a transistor.

I 100% doubt that the transformer is in any way related to this now, because the odds of two power transformers blowing, and especially still have accessory power working on the back terminals,
would be ridiculous.   I am really thinking that it's those power transistors now, especially since they are
a known failure point.

[sd75i]

      Ok I did that test with the measuring of circled B and E and got No reading.  Both sides.  If it helps,  I did accidently cross B and C with + voltage lead and throttle light lit up?  It didnt matter whether throttle was off or on full.  Im trying to get part number now.

[sd75i]

  All i can find on part is F S?9300 801 korea

[peteski]

The 2 large blue cylinders with leads on each ends are electrolytic filter capacitors (caps).  I assume each one is for each throttle. One lead is welded to the metal end (negative) and the other one goes into a black a rubber plug (positive). Put your meter on DC and 20V range and measure the voltage between the leads of each cap.

Then leave the negative lead of the meter on the negative lead of the cap and then use the positive lead of the meter to measure the voltage on the B, C and E of the transistor corresponding to the side where the blue cap is (left cap to left transistor).  Take the measurement on each lead of the transistor while you are turning the corresponding throttle knob from minimum to maximum and note the voltage readings as you turn the knob.  That might take 3 hands!