PWM Problem

I've checked all of the threads that I can find, but can't find my solution. Time to ask for help from the group.

I bought a Bakatronics FK804 pre built to control my BK, switched out C1 to a 2.2uF cap, hooked up to my SSR to verify that all is well before buttoning it up, and the SSR light is on solid. Tried all of the basics, cap polarity, even tried switching out to a 4.7uF, thought maybe my cap was bad, but no luck.

Using a 12v wall wart, getting 12v out, just no duty cycle - steady output. One interesting point that may help diagnosing this problem is that the transistor on the board gets really hot, really quick - tells me somethings wrong but I can't find it.

Any thoughts?

Have you checked the ssr for proper operation? It could be a bad ssr as well.

Yes I have - SSR is fine. I've manually checked it, and I've checked the output of the PWM with a multimeter, with no success. The only thing I can think of is a bad component - this thing is pretty much a no-brainer, especially when you get it pre assembled.

I picked up a new 555, I'm going to plug it in to see if that fixes the problem.

transistor on the board gets really hot, really quick - tells me somethings wrong but I can't find it.

Click to expand...

that just tells you that its constant on, which you know. the more % of the time its on, the hotter it will get. 100% = hot.

if you can find a schematic for that board, i could tell you more. i wasnt able to quickly find one though.

Thanks for the assistance, but since the board has pretty well been destroyed by my diagnostic process, I will be ordering a new one from Bakatronics. Never did figure out what the problem was, but I will for sure be testing the new one prior to changing out the cap.