M100B Pin bank coil

[andylevine]

After WAY too many months of refurbishing (don't ask), I am finally getting around to the mechanical parts of my 100B.  After cleaning and restoring the Selection Unit, I thought I would have a go at cleaning the pin bank.  Removed the slide from the bottom, and the board for the first (or last) bank.  Here's a pic of what I encountered:

imgur.com/a/qFHEr

I have to think that the circled coil (the first one on top) looks really fried. burnt up. toasted.

Being a rookie at this sort of thing, am I correct?  If so, what is the best way to fix?  Just replace the coil? Replace the entire set of 20 coils? Find a new pin bank??

HELP please!!

Thanks
Andy

[Ron Rich]

Hi Andy,
Yep--fried, and unfortunately, the 3rd coil looks swollen too --Changing them is a "bitch job", but can be done. Before you even THINK of plugging that SAU back in be 200% sure the CCU is operating as it should. The rotary credit wheel must "snap back" instantly when you pull in the plunger and let go. Timing relay contacts must be clean, & correctly gaped. Start pressure correct-- CCU fuse MUST BE a 1-1/8, or less--1.6, 1.5. or 1.0 is best. Ron Rich

[andylevine]

Darn, not the news i wanted to hear, but mostly what I expected. Any idea where to get replacements? A quick look at the usual places brought up nothing obvious. any pointers appreciated. Buy a parts unit on eBay???

Thanks
Andy

[jukeboxmarty]

Normally Bill Butterfield will sell you single coils, but it seems like he's taking a break from his business right now.

I would check the remaining coils with a good ohm digital ohm meter to make sure the rest of them measure OK. This may save you from having to disassemble the pin bank a second time if another coil is bad.

Approximately what area are you in? Maybe there's someone local.

[Ron Rich]

Vern (Jason) Tisdale--look him up in FAQ's above ! Ron Rich

[andylevine]

Marty - Thanks...I did check all the other coils and they tested fine. Ron, forgot about Vern...I bought the recap kits for my amp and selection receiver from him moons ago. Finally going to get around to doing that over the Thanksgiving break.

[gar]

what should the Ohms of the pin bank coil be ( + - ) If working ok ?

[Ron Rich]

Sorry, I don't recall that as I fire them and see how much current is drawn--1.25-1.5 is OK Measure a few of them to determine that value--

[steveb]

As Ron pointed out the circled coil and the third coil are shot. Resistance for the 5 Group coils is 5.6 +/- 0.1 Ohms. Resistance for the 100 Selection coils is 4.6 +/- 0.1 Ohms. Cancel coils on the contact block are 24 Ohms. These were measured on my M100C using my digital meter. Your measurements may be slightly different.

Victory Glass has the block of 20 coils for sale from their used parts department. Not sure what you will get on eBay. Again, as Ron pointed out it is a pain to replace individual selection coils. And since you need to do two of them just get the whole block. Follow the wire colors one at a time when you swap out the old one for the new one.
Steve

[gar]

Thank you STEVE . Even though the selection coils look burnt they test 4.2 ohms so i don't need to change them .