Pro Planer speed control box problem

tdubnik · Post by **tdubnik** » Thu Nov 13, 2008 8:19 am

[ATTACH]2358[/ATTACH]

[ATTACH]2359[/ATTACH]The last two pictures.

dusty · Post by **dusty** » Thu Nov 13, 2008 9:07 am

It looks as though you just might have a keeper. The heat damage does not seem to be extensive.

With an ohmmeter, can you tell if the coil in PIC 029.JPG is open or not?

The waxy looking substance puddled at either end of that coil I suspect is melt down from the coil.

Do you have any experience working on printed circuit boards?

On the areas where you have to solder, you must first remove that green sort of covering. It is there to prevent corrosion of the printed circuit.

tdubnik · Post by **tdubnik** » Thu Nov 13, 2008 9:11 am

dusty wrote:It looks as though you just might have a keeper. The heat damage does not seem to be extensive.

With an ohmmeter, can you tell if the coil in PIC 028.JPG is open or not?

Do you have any experience working on printed circuit boards?

On the areas where you have to solder, you must first remove that green sort of covering. It is there to prevent corrosion of the printed circuit.

I haven't done any real work on printed circuits. I could manage to solder jumpers; I think.

As far as the coil being open; could this be checked with a continuity test? ( I assume you mean pic 29 or 30 and not 28)

Ed in Tampa · Post by **Ed in Tampa** » Thu Nov 13, 2008 9:17 am

If it were me I would try to run two jumpers I have them as straight red lines on your photo.
I would then touch my soldering iron to the 2 red spots as they might be cold solder joints.
Lastly I would run something sharp down the board blue line to make sure there is no short between the two circuits on either sid
Then I would try it.

The coil may be shot but I would try what I suggestted first.
Ed[ATTACH]2360[/ATTACH]

dusty · Post by **dusty** » Thu Nov 13, 2008 9:31 am

Ed's advice is excellent.

A simple ohmmeter check of the coil might work but that is hard to say without seeing the circuit. The coil might be shunted by other components giving a false reading. You may have to unsolder the coil from the circuit to be able to tell.

Follow Ed's advice first. You just might fix the circuit without doing anything to the coil.

If your ohmmeter leads are sharp, you can probably penetrate that varnish coat to make the resistance checks that Ed suggests.

A SHOCKING REALIZATION: The innards of this control box sure do not look like $300 worth of components or design engineering.

johnm · Post by **johnm** » Thu Nov 13, 2008 9:36 am

tdubnik wrote:The last two pictures.

Can you read the number on the component that is attached to the aluminum heat sink at one end of the board? I suspect that it's the thing that has gone south. Everything else looks intact.

Looks like about $10 worth of parts in there....

tdubnik · Post by **tdubnik** » Thu Nov 13, 2008 9:53 am

johnm wrote:Can you read the number on the component that is attached to the aluminum heat sink at one end of the board? I suspect that it's the thing that has gone south. Everything else looks intact.

Looks like about $10 worth of parts in there....

The part is a small black rectangle with 3 leads soldered to the board. It appears that the numbers are 0973.

This entire board is pretty small measuring 1 1/2 by 2 inches.

Ed in Tampa · Post by **Ed in Tampa** » Thu Nov 13, 2008 9:54 am

Very very few electronic circuits are worth what we are charged for them.
Perhaps whatever the end result of the this failing economy will teach us all to price products by their actual worth instead of what we can force people to pay for them.

If you want a shock go price a 220V well pump motor control box. It has two components a relay and a capacitor. If you buy the capacitor from a well company the charge is $90. If you buy the relay from the a well company the price is $90. They only sell a replacement control box.

Buy either component from Grainer the price of the capacitor is $7 and the relay is $8. Otherwords putting the together and metal box cost $75.
That is crap!

Oh add installation by the well company and the bill with travel, time and components is well over $200. That is not one well company that is all in that I called in town.

tdubnik · Post by **tdubnik** » Thu Nov 13, 2008 9:54 am

Ed in Tampa wrote:If it were me I would try to run two jumpers I have them as straight red lines on your photo.
I would then touch my soldering iron to the 2 red spots as they might be cold solder joints.
Lastly I would run something sharp down the board blue line to make sure there is no short between the two circuits on either sid
Then I would try it.

The coil may be shot but I would try what I suggestted first.
Ed

Thanks for the suggestion Ed. I'll give it a try this afternoon.

dusty · Post by **dusty** » Thu Nov 13, 2008 9:56 am

I don't see anything that I recognize as a diode (rectifier) but there has to be one. With amount of heat developed, the current through that diode would have been significant. The diode would therefore be suspect also.

The diode might be the form around which the coil is wound.

I am attempting to create a drawing of the circuit using the photos provided. I think it can be done (unless there are components under the potentiometer that can't be detected).

Are there any markings that might be part numbers on the components. I am particularly interested in the tan colored one (w/red,white,orange and black strips).

Is there a component up inside of that metal bracket (029.JPG)?

The resistors look fine. When you measure the potentiometer, do you get an indication that it works (a variable resistance)? In 029 I can see a number which I would bet is the part number for the poteniometer.