Shopsmith Forums

Today my power pro just shout down with running the band saw. The saw was just running the blade no wood stock. No display no rotation.

I moved the switch to off and then back on and the display came back but my passcode would not accept. I them moved the switch to off the on again and all was normal.

Anyone else having these symptoms?

RICK

Rick
I did have a problem similar to this about three days after I got my factory built PP. I turned it on and all I got was a green display but no info and I could not input any speed or other info. This happened on a Sunday and when I called SS on Monday the problem had cured itself. The explanation was that some of the capacitors that were used had to be conditioned to the voltages. Being an engineering electronic tech I felt that I was getting the old blow off. Something seemed to have self healed. It will probably rear it's ugly head again sometime in the future but it has been working OK for the past 3 years.
Bill V

wa2crk wrote:Rick
I did have a problem similar to this about three days after I got my factory built PP. I turned it on and all I got was a green display but no info and I could not input any speed or other info. This happened on a Sunday and when I called SS on Monday the problem had cured itself. The explanation was that some of the capacitors that were used had to be conditioned to the voltages. Being an engineering electronic tech I felt that I was getting the old blow off. Something seemed to have self healed. It will probably rear it's ugly head again sometime in the future but it has been working OK for the past 3 years.
Bill V

Interesting!!!!!!!!!!!!!!:rolleyes:

There are actually app-notes for Electrolytic capacitors, even in modern-day, talking about "re-forming" them after storage. I found one from EATON / Cutler-Hammer on a web-search. Don't know if that's really the issue or not for the PowerPro.....

I was told by one of the engineers that I worked with at R------n that some tantalum caps could act this way but he never convinced me.
Bill V

I retired from 45 years in the electronics industry. We had a theory about electronics. It has two states of operation.
1. intermittent
2. dead

Your Power Pro is obviously working normally in state #1.

If electronics was truly reliable, I would not have had a job for 45 years troubleshooting and repairing it.

garys wrote:I retired from 45 years in the electronics industry. We had a theory about electronics. It has two states of operation.
1. intermittent
2. dead

Your Power Pro is obviously working normally in state #1.

If electronics was truly reliable, I would not have had a job for 45 years troubleshooting and repairing it.

Wanna go back to good old-fashioned mechanical distributors in your automobiles?

In my experience, it can be difficult to design a truly bulletproof circuit -- especially power electronics. But not impossible. The key is to keep all component stresses well within ratings. (Which is much easier said than done.)

BuckeyeDennis wrote:Wanna go back to good old-fashioned mechanical distributors in your automobiles?

I actually still have some of those old points distributors on some of my older vehicles. They are 40-45 years old and running strong without having their first problem yet. They require more maintenance than electronic distributors, but an electronic one will leave you dead on the road a lot more often than a mechanical one. Mechanical parts seldom have the intermittent problems so common on electronics.

garys wrote:I actually still have some of those old points distributors on some of my older vehicles. They are 40-45 years old and running strong without having their first problem yet. They require more maintenance than electronic distributors, but an electronic one will leave you dead on the road a lot more often than a mechanical one. Mechanical parts seldom have the intermittent problems so common on electronics.

And the old points were 'repairable' out in the boonies with no 'normal' tools.

JPG40504 wrote:And the old points were 'repairable' out in the boonies with no 'normal' tools.

I can't argue with that one! Although it did get me chuckling over my one experience with a dead distributor. Somewhere back around 1985, I was on an expedition with a bunch of OSU engineers, about halfway through West Virginia on the turnpike. Yup, the very definition of "the boonies". One of the vehicles was a '60's vintage Dodge Power Wagon, and it decided that was the perfect time and place to die.

So a whole bunch of young Mechanical Engineers start looking for the problem. To their credit, it didn't take them too long to discover that the distributor shaft had broken. Why, I have not a clue. But I saw it, and it was fer sure broken.

Since this was a actually small caravan, we dispatched another vehicle to go find an autoparts store. In the middle of West Virginia. A couple hours later, it finally came back with the prize. Oops, wrong distributor. The shaft was too long, and the flat was in the wrong position anyhow! And Murphy had made sure that it was by now after 5:00 PM, which back then meant that all the all the parts stores were closed for business. Bummer.

Just in case any young whippersnappers read this, I must point out that cell phones would not be an option for another decade or more. At least not on the West Virginia Turnpike.

Well, the best thing about that Power Wagon had to be the front bumper. Solid, flat, and immense. Looked like a friggin' welding table. And we had a full toolbox on board as well. Before long, those ME's had the shaft from the new distributor C-clamped to that bumper, and proceeded to cut it to length with a hacksaw. Then, using the broken shaft for reference, they took a bastard file and made a new flat in the proper orientation.

By 6:00, they had the new/modified distributor installed, and the old Power Wagon fired right up. Just try that with a transistor!

But pushing a million miles later, driving cars with electronic ignitions well into 6-digit mileage, I've not had one die on me since.