Sun Distributor machine repair

[Lynn]

So.... I bought this really cool vintage 680Distributor machine. Have not had time to mess with it. But, a really good buddy needs to use one right now (well, within the next few weeks), so I chucked a 480 distributor in it yesterday, and tried it out. I would really like to get it working for him. You can't imagine how much he has helped me out over the years.

Spun up just fine, speed control works perfectly, and it is nice and smooth. So far, so good. Calibrate the dwell meter, and the dwell function works fine. Adjusted the points.

Switch over to RPM and I get nothing. Of course without RPM function, the strobe light indicating advance isn't working either.

I don't want to just throw parts at it. I may end up buying a strobe light, but figure if the RPM isn't working, it probably has no signal to the strobe. I plan to take it apart and see if I can find a problem. But, realistically, figure the problem is internal to a particular component.

Is there a good downloadable repair manual available? I found Paramount (who sells lots of parts and machines). Didn't see a manual, and am guessing he doesn't want to share too much knowledge.

Second choice would be a hard copy manual, but guessing that is almost non-existent.

Lastly, is there someone here, or that you know of, who can point me in the right direction as far as what to look for.

As always, thanks for any help.

[L78steve]

Call Paramount. He's a good guy and will sell you only what you need with instructions.
If you need him to do the repairs you wont be disappointed with the quality and price.

[anodyne33]

Wouldn't hurt to ask at GarageJournal.com

[Lynn]

May do that. Called Paramount today, but haven't heard back yet, which is understandable given that he has another full time job running his shop.

I have an old Sun document entitled "Repair Manual" but it is only 9 pages, and doesn't have any diagnosis or trouble shooting... only pictures of parts and part numbers. I also have a schematic but it is blurry and hard to read.

Found a real Repair Manual on ebay (77 pages), but it is for the 600 model, not my 680.

[ZLP955]

Lynn there is a guy over here who rebuilt and recurved my 480 and 488 distributors, very knowledgable old retired guy who does this for the love of it rather than financial gain; I'm not sure but have an idea he uses a 680. I will check and see if he has any knowledge of what your problem could be, or if he has any manuals/service books.

[L78steve]

What I did with my unit (with help from paramount)was remove the tube and convert to solid state, Replace the old capacitors and some re-wiring.
Your electronics are probably toast.
Mark can tell you what you need to do and supply the correct parts.

[Lynn]

Update.

Talked to Mark at Paramount today, and he suggested first changing the AA battery. Of course, I am wondering where is the battery. The only other one of these I worked on had two little access panels for batteries. This one did not, so I assumed there wasn't one. Wrong. Took off the back panel, an sure enough. A battery that had been there since 1982 (or before, 1982 was the last time this machine was serviced). IT STILL HAD VOLTAGE!!!! Not much (.42 instead of 1.66).

Anyway, put in a new battery, and that is not my problem, so I am guessing I will go ahead and purchase the capacitor/resistor kit and go from there.

[ZLP955]

Lynn I sent you a PM which may be of help

[ZLP955]

Thought I should post the suggestions that I pm'd Lynn in case they may be of help to anyone else.
The first guy I mentioned earlier only suggested contacting Paramount, but then I managed to find contact details for another very knowledgable guy that did another distributor for me some years ago. His advice is as follows:

"For the RPM Meter to work, I would say that all he needs to do is change the "AA" and "D" Batteries on the Circuit Board below and it will work fine.
The usual reason the Strobe Light doesn't work is probably that the Capacitor Board below the "Light House" has had one or all the three Capacitors mounted on this board to fail, that's a cheap and easy fix. If that doesn't light up the Strobe Light, then send the Power Supply to Mark Saunders and Mark will do a Capacitor, Resistor and Diode upgrade on the Power Supply and then it will be ready for many years of work."

Sounds like Lynn was already on the right track with the AA battery, but this advice offers a little more to follow up on with the D battery, capacitors and if those don't resolve it, Mark at Paramount.

[mockingbird812]

Mark also sells a plug-in DC board to replace the batteries.