HI Im quite a novice, I am looking for the circit diagram, for my treadmill controler board. Model HS-T500 Version HSMD-70-02, I found it had a number of poor solder joints and a zenor diode that had blown, i replace the diode but couldnt find the value of the old one and it has now blown a transistor,

 

Don't recognize those numbers, can you post a pic?
Max.

 

HI thanks for taking a look, the problem was error 4, then 40,41. I removed the motor and took it to work and inspected brushes etc. the ran it on the dc power supply and it ran fine. reinstalled motor and put it in diagnose mode and forced the belt around and it clocked up speed so that shows the speed sensor is not the problem. did a few voltage checks and found the rectifier wasn't getting 230 Ac, removed the board, removed and checked relays they were operating fine, the circit was telling me the middle relay coil windings had a short across the feed terminals. found the zenor diode that i have replaced was shorted out. don't know what value it should be put in a 7V one error still there, but now the raise and lower only went up. the middle relay is the raise and lower feed relay. Replaced the diode with a 3.4 volt one and the transistor by the last relay had blown.

 

HI thanks for taking a look, the problem was error 4, then 40,41. I removed the motor and took it to work and inspected brushes etc. the ran it on the dc power supply and it ran fine. reinstalled motor and put it in diagnose mode and forced the belt around and it clocked up speed so that shows the speed sensor is not the problem. did a few voltage checks and found the rectifier wasn't getting 230 Ac, removed the board, removed and checked relays they were operating fine, the circit was telling me the middle relay coil windings had a short across the feed terminals. found the zenor diode that i have replaced was shorted out. don't know what value it should be put in a 7V one error still there, but now the raise and lower only went up. the middle relay is the raise and lower feed relay. Replaced the diode with a 3.4 volt one and the transistor by the last relay had blown.

Hi i have on the same machine error 91 and speed sensor no supply. Sensor is new.

 

Hi i have on the same machine error 91 and speed sensor no supply. Sensor is new.

Hello, I also have one of these boards with a blown/cracked RT1 thermistor. The value on the thermistor case is:

001
20

I suspect it is an NTC type. If you still have the board, would you be able to measure its resistance at room temperature?

Incidentally before the thermistor blew up, I also had error code 91 and 92.

I suspect the original issue is the optoisolator on the speed sensor. I’ve ordered a replacement optoisolator to try.

... but I need the replace the RT1 first