*resolved* - Ambex YM-10 Watlow Controller


New member
Aug 17, 2022
Visit site
Hey everyone,
I will make corrections if violating any rules, but I have a rather urgent situation. I am pretty new to the industry and am on a STEEP learning curve currently.
I purchased a 2003 YM-10 Ambex along with an established roasting company that I had worked for prior to purchase. The previous owners did minimal maintenance on the machine and it still had the original thermocouple and watlow controller from when they purchased the machine a decade or so ago. The buttons on the watlow 935a were always a little wonky, but worked okay. I swapped out the thermocouple, not realizing it must have been a J type whereas I purchased a K.
Did a roast and figured it was a setting issue when the temperatures weren't reading correctly.
Consulted the manual and got ready to switch the setting to a K-type.

While I was in the menu the buttons failed completely and the device is unresponsive.
I have replaced the button pads and nothing - the connections seem to be scuffed/worn down.

**Editing to say I purchased a part on Ebay, but it arrived broken (picture) and the seller has said it was accidentally listed. They have issued a refund. BUT I now have no controller again. I need to find one ASAP. Please help. I ordered an ez zone PM3C1CJ-AAAAAAA based on another thread, don't know if that's even the right one, but it is an almost 6 month lead time o_O


  • 20220817_130741 small.jpg
    20220817_130741 small.jpg
    185 KB · Views: 72
Last edited:
Hey there. Sorry you are having an issue. Try reaching out to Paul Ribich with roaster dynamics. He is a great dude and knows everything about the Ambex roasters. Good luck and let us know how it turns out.
I have a 2002 YM-5 that currently has a Watlow ez zone model number PM3C1CJ-AAAABAA. This replaced the original 935a. The Watlow ez zone line replaced the 935 line and are compatible. I did a quick search and was able to find a place that has 1 that can ship by Aug 23. I'll PM you the venders website.
Last edited:

Latest posts