Filter (power) board replacement B35379

The AMA180V minilathe, equivalent to the Warco WM180 is a very useful (if tiny) lathe. I bought mine second hand, and soon after I had it the brushes failed. Changing them was a bit of a marathon- which sadly I didn't record as it happened before I had adopted these blogs as my preferred method of  record-keeping.

The lathe has been really useful although I don't pretend to be an accomplished fabricator, I use mine mainly for bushes and fasteners, but it subsequently developed a second fault in the the LCD speed display suddenly went blank.

Fortunately you can buy a handheld rpm meter (also useful for my drill and the occassional motor) so the problem didn't stop me using the machine. However it obviously needs fixing.

Chatting with amadeal (very helpful guys) showed that the fault was either the LCD screen itself or the power supply board. Easy enough to check as if you pop the display out of the front then there should be a voltage (5v) detectable across its input. Of course the wire might be broken or detached, so check the connection and output at the other end of this lead on the power board itself.

This was the problem- LED display blank, Lathe working but had to use a handheld rev meter to set speeds. Checking the two input wires behind revealed no voltage (should be 5V) either here or at the other end where it meets the horizontal base- mounted filter (power) board.

Remove the Allen screws to detach the rear panel, note lower right is the small screw, all others are the same size.

Back folds off with control board on the rear. I had already labelled all leads with the terminals they connect when I had to remove this last time(changing the motor brushes)

Filter board on inside base of lathe. The LCD connection is the smaller of the two clip terminals (ie the left hand one) . The board is retained by 4 small nuts and allen capped bolts. Sadly these are accessed from below. The front two can be removed easily but the rear two require that the base of the lathe be detached so you can get an Allen key underneath before they can be undone.

general view of connections

general view connections

I took some general views just for records in case they were required, in fact they werent but I present them here in case they can guide anyone else.

The lathe is heavy- surprisingly for such a small machine but tilting it allowed the base nuts to be attacked.Remove bolts holding lathe to its base piece. The motor end is retained by a sliding bolt fitting and the tail end by a single hole.

The lathe can then be slipped  off the base and tilted over to expose the small Allen capped bolts beneath. This releases the power or filter board and the insulating tray beneath.

The board is mounted on an insulating plastic tray

New board available from Amadeal. This is a B35379 filter board or power board. Connections swapped over individually. before refitting the board.

Operation was a success- but patient died! This process restored function to the LED display but sadly now the lathe didn't work! Lesson here to be more careful with the loose rear panel. This had seemed too much trouble to detach, so it did get pulled a little. I found one of the wires had pulled off and reconnecting this restored function.
Job done and lathe back in service!

Looking at the rear of the removed filter board I think has shown the problem...

Spots of corrosion on the rear of the old board.