FK18SM-12 & FK10UM-10 replacement

I Googled the two part numbers in your title line and immediately came up with their datasheets. Can you not just spec replacements parametrically?

Here's how I would do it:

- note the most important specs from the two data sheets. - case style, wattage, voltage, current etc.

- go to an electronic supply web site like Digikey.

- search the MOSFETs - there'll be thousands.

- filter based on ratings that meet or exceed the originals. Now there'll be hundreds or dozens.

- filter for what is in stock. Pick ones where the supplier has lots of stock and the price is best.

- examine the data sheets looking for gotchas: less-common parameters that might be incompatible.

- Buy them and hopefully win. Unless the application is quite specialized, this should work fine. These don't look particularly unusual to me. Looks like something you'd find in the electronic ballast for a big lamp.

Best of luck to you.

A quick look and I think an 18n60 would be a good replacement for the FK18sm

Dan