View Single Post
Old 08-19-2018, 02:03 PM   #1
Badcaps Veteran
davg's Avatar
Join Date: Sep 2008
City & State: NL
My Country: Canada
Line Voltage: 120VAC 60 HZ
I'm a: Knowledge Seeker
Posts: 409
Default Treadmill DC Circuit no motor start

MC-02 Control Board
I picked up a treadmill at a yard sale (was hoping to use the DC Motor and Controller on my drill press) brought it home plugged it in and it worked fine. I removed the motor, controller and the control panel from the frame and tested it on my bench it would not start the motor? I reinstalled it back on the treadmill frame and it still would not start the motor? All the wiring hook-ups was checked and double checked as per the wiring diagram. I must have damaged a component on the board but there is no evidence of that? The board is a MC-02. I checked some of the voltages on the board and recorded the following;
1) 120 VAC across LG4, LG5.
2) 5VDC across LG1 and LG3.
3) No voltage across LG6 & LG7 (To Motor)
4) Ground to LG6 is 54VDC the same on LG7
5) Probes across LD1 is 12VDC (not sure what LD1 is)
6) If I jumper center leg and right leg of Q4 motor will run?
I have no idea what the voltages should be except the 120 VAC and the 5 VDC although 54 VDC seem to be present in many places on the board?
I have no idea what happened or how to troubleshoot the board?
I have included close-ups of the board front and back as well as the voltage diagram showing the wiring hookup.
I know there are some capable people on here who know at a glance what the problem might be any help would be greatly appreciated.
Attached Images
File Type: jpg Control Board bottom.JPG (1.44 MB, 17 views)
File Type: jpg Control Board top.JPG (1.62 MB, 31 views)
Attached Files
File Type: pdf MC-02 Voltage Diagram.pdf (6.11 MB, 10 views)
davg is offline   Reply With Quote