Hi,
I am trying to find out what happened to my Treadmill using the MC2100E controller. When pressing SP + button, the motor does not start. I started by doing some tests. On pressing SP + button, SCR Q1 switches on through Q3 (2 KHz pulses) & Q4 , and sends the DC supply to the IGBT driver, but the motor keeps off. When checking, I found that the IGBT power driver was nearly open! Replacing this IGBT made no progress. Checking the current sense resistor R36 and the two 1M resistors (R29 & R32) which are connected between the IGBT and the CPU were all found good. There are good voltages on the 7805 regulator and +12v on reservoir C2 . Besides these, I also checked the console pins voltage on socket HD2. The PWM Blue wire, the tach Green wire and the DC +12v on the Red wire look good. I am also noticing that the onboard LED is always OFF. According to the attached document, it says that the controller is not receiving power although I checked some voltages on this board as above.

Any suggestions will be most welcome.
Thank you,
Carag

 

Just ensure that there is power to the Micro processor.
Normally at power up, the LED comes on after a brief delay and stays on steady, until a command to move is received.

 

First of all, I would like to thank you MaxHeadRoom for sharing the information on this topic. Although your reversed-engineered diagram is not exactly the same version I have, I found yours very helpful. Yes, there is +5v on pin 20 of the CPU.

Thank you,
Carag

 

Can you post a copy of your version?
Is it for your model?

 

I attached a photo of the board.

 

Although your reversed-engineered diagram is not exactly the same version I have, I found yours very helpful.

So do you have a reverse engineered schematic for yours?
That looks like a very trimmed down version of the board.
It must be fairly recent, however, as it uses SMT components.

 

No, unfortunately, I haven't got a schematic of my version. I was referring to your reverse-engineered schematic in one of your previous threads where there are some similarities. It is not so common that a power transistor goes o/c as normally it goes s/c between c & e as I found the IGBT. Until now, I cannot find any relation between the o/c IGBT and the LED Off state.

Thank you,
Carag

 

Normally if the3 Micro detects any kind of fault, it would flash a code on the LED, not just remain off.?

 

Hi,
Today I made some other checks. I started with voltage readings on the LED which resulted to be o/c! After changing the LED, at last, I can see the flash codes. The LED is solid lit while on standby and when pressing SP + button, it blinks quickly. These seem to be normal. I also took voltage readings on IR2127. Pins 1 and 10 are at 15v, pins 4 and 5 are at 0v, and pin 3 is at 4.8v. Pin 2 is 0v on standby and 0.19v on running. I am not sure about pin 2 and pin 3 readings especially pin 2 where there is only a 0.19v voltage change.

Thank you,
Carag

 

Pin 10?
AFAIK these are 8pin IC's?

 

Pin 10?
AFAIK these are 8pin IC's?

I was my mistake. Pins 1 and 8 are at 15v.

Carag62

 

All the later MC2100's I have come across have used the MIC4427 or similar.

 

Hi, this is my conclusion. Finally, I replaced the IR2127 and now the treadmill is working again. So the main faulty components were the IRG4PC40K (IGBT) and its driver the IR2127S. In my opinion, the o/c LED found during the fault finding was not directly related to the main fault.

Thanks,
Carag62

 

I attached a photo of the board.

hi bro i need number of integrated cercuit 8 pins U5