It's people like yourself and Homebrew and your willingness to help that deserve the credit. I'm not very courageous - only desperate! After running the test with the drill over and over, I'm still not seeing the fault. I can easily try warming the board a bit with a hair dryer as Homebrew suggests. Until and unless it appears under the test conditions, I'm less inclined to see this as a fault on the display/encoder. As for brushes, I'll be checking those later today. Fortunately, I have both a spare set as well as a new, unused motor.Good advice there from Homebrewed. I salute your courage in diving into this thing- there's a certain satisfaction in fixike you ale ling something with little info to go on.
Even if the IC number has been erased, you might be able to locate it online by typing in the function "3-1/2 digit tachometer IC" or something like that.
appears, I'm less inlined to
The hunting you mentioned could be a factor or not. I wouldn't expect the brushes to be worn unless the motor has lots of hours on it.
If you can read the part # from the opto interrupter post it here- I have some opto databooks
What's worrying me now is the possibility of a fault of some kind with the KB controller itself. I never asked Amadeal what warranty if any, came with the box. I will have to talk to them about returns if it turns out to be faulty. I haven't the knowledge or the tools to establish that other than by the process of elimination, though. Still, I'm not not at that stage yet.
Thanks again for the continuing help.
Trevor