This is on Mystic, 1980 SS. The board with the fuses, just above the transformer.

The 43VDC power is not getting to the Allteck solenoid driver board (the D29 led doesn't light). Allteck says the power comes thru fuse F4. The fuse tests good.

There are three pin connectors on the board. Jiggling the wires didn't help any. Which wires in the pin connectors should I be testing / re seating?

I tried looking at the schematic, but didn't see anything that looked like wires coming off of a 43VDC fuse on the board. The fuses are only shown on a page with part numbers.

thanks!

Mike

[EDIT after doing the testing indicated below and writing the post, putting the multimeter away, the wire just came off the red probe. Doesn’t appear to have been soldered on all that well. Could explain some weird readings. I’ll report back after I get a new probe. Gotta love that Harbor Freight quality!]
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Please bear with me, I'm a real novice here.

Removed the fuse. Put the probes on each side of the fuse holder. Nada. Had the multimeter at 10A, red probe in the 10ADC plug and the black in the Com plug.

Moved the red probe to the V mA plug, switched the dial over to DCV, and tried it with probes on each side of the fuse holder at 1000 and 200. zero.

At 20, the reading jumped up and down from .00 to .05, never resting. Tried reversing the probes in case it mattered, same results.

Maybe I should have mentioned that the transformer is now humming, too. It starts soft, gets louder for about five seconds, then stops. Does it again after a little bit.

New multimeter acts just like the other one, so I guess the above readings are legit. No current coming across the fuse terminals.

A friend lent me his high dollar multimeter, so now I'm using that.

I'm giving up on the HF multimeter. The instructions clearly say that on ohms set at 200, touching the probes together should result in a reading of zero. It doesn't. The numbers jump around, never coming to rest at zero. WTF?

52.3 reading on both sides of the fuse. 52.4 reading on the bottom of the fuse holder with the fuse out.

The LED that would indicate 43v to the board is out. Allteck said that meant the board isn't getting the 43v. Don't know how to check & verify that. Reseating the connectors didn't help.

I'll get back to you on that after I do some studying on what "bridge" and "MOV" mean.

I'm guessing that TP4 is for testing F4 ?

Thanks. I ordered a smaller tip for my soldering iron last week, & will resolder the pins when it gets here. Amazon is running real slow these days.

There is a burnt pin connector (female), but the machine is only on when I am there, and I didn’t smell anything. Figured the connector had burnt before I got the machine.

Tried looking at the schematic to see which pin went to F4, but couldn’t figure it out.

Great. Thank you both very much.

Looking at my schematic, now I see F4 with the little fuse symbol, and it goes to the pin connectors.

The pins on the schematic are not in numerical order. J1 goes 1,7,8,6,4,3,5,2. My guess is that they are out of order for clarity on the schematic, and 7 means pin seven even though on the drawing it is the second in the sequence. Am I getting that right?

The pins shown in yellow on the schematic above all had continuity to the fuse.

The really burned one goes to general illumination, which works, so that's not it.

So, it looks like my next step is to get new connector plugs, right? Hopefully, Microcenter has them. And the clips. And the crimping tool.

Yes, there is power to the pins, but there is something funny about pin 13 on J3. The pin is there, and it has voltage. But there is no wire in the connector.

Not a disconnected wire hanging in the breeze, mind you, but really no wire. Tracing the bundle up to the first little zip tie, there is no wire. How can that be ? Per the schematic, the only blank spot should be 7.

Maybe I should go back to making yard art for a hobby.

IMG_3858 (resized).JPG

Ah-HAH! Thanks.

It looks like the transformer board is ok, so the next step is tracing the wires from that board to the solenoid driver board.

If I am reading this right... looking at the Plug Connectors schematic, pin 9 on the J3 connector plug on the transformer board (A2) goes to pin 5 on J3 of the solenoid board (A3).

Testing resistance / continuity between the two plug connectors at 9 & 5 reads .4 Is that my bad wire / bad connection? Seems like a good connection would read zero, right? Or is .4 close enough?

The labels on the solenoid board (Alltek) are P, not J. Easy enough to guess that Alltek is using Ps instead of Js, but why would they? I thought I better ask in case I'm misunderstanding something.

No. Could use guidance on finding the right ones, and the little clips that attach to the wire inside the connectors, and the right crimping tool. Tanners electronics didn’t have them. Didn’t see anything that looked correct at MicroCenter's website.

Ordered connectors, crimp thingys, and key plugs from Great Plains. Ordered the crimp tool from Amazon.

Will have everything in about two weeks & can get the connectors replaced, god willing and the creek don’t rise, and hoping I ordered the right sizes on everything.

Thanks for all the help, & back at you when it’s done!

I wasn't going to take off the boards and do the pins until I'd re-done the connectors.

Then again, I've got two weeks to kill before the connectors & clips get here. I think I ordered the right stuff, although I guessed on the wire gauges for the crimp clips. Figured I can't go too far wrong.

But, while we are on the subject, what is the name of the tool used to release the plastic clips holding the board to the machine? Hard to search for a tool, not knowing what its called...

The A3 board looks brand new, but the date on it is 2010. Maybe they designed it in 2010 and it was purchased more recently. I just got the machine in late October.

My new small chisel soldering tip came in, so I could take off the board and resolder the pins. My guess is the wires are just old.

Making Progress... OR Good News / Bad News

I re-soldered the pins and some of the other solder points on A3 (the solenoid board). Didn't change anything. Re-soldered pins and other points that looked bad on A2 - the transformer board. Also messed with some wires going into the J3 connector on A2.

The Good News... the solenoid board is now getting the power it needs. That LED indicator light on A3 is lit and the machine boots up!

But, Alas! The game won't start. No stuck switches. Maybe I messed something up, when re-soldering points. Maybe this was part of the original problem.

What's my next step, please?

Re-seating the bottom right connector at the MPU fixed it.

All is well in Mystic land!!

Thank you so much for your patience with me. I really appreciate it.

For me, the best part is doing all those solders without messing up anything. And being able to play, of course.

Mike