I think they should be similar and able to be swapped into a Williams pin. If not I recommend a colordmd. They are $360-$400, but it would really make your pin look great and more modern. I have a colordmd on all my older willams pins, best mod in my opinion

Dmds should be compatible. I've used ones from 1990 in 2009 Sterns and vice versa even. Maybe you've got a dmd driver board problem too?

Check the power connection didn't come loose on the DMD driver. Be sure the tiny ribbon cable is seated correctly.
I also agrew with the color DMD option. I have one in my WCS. What an amazing upgrade! You won't be disappointed and it adds reslae value to your game.

Try a Stern DMD with a separate 5V supply(run a wall wart from the utility plug if nothing else). You may have an issue with the high voltage side which caused your initial problems.

To confirm your original question - yes (for-sure) a Fish Tales DMD will work in a WCS. There were different manufacturers of DMDs for the BW games (Cherry, Vishary etc) but they all should interchange from the earliest Gilligans to the newest Cactus Canyon.

If something is not working, it is not because they are incompatible.

Therefore, if a DMD works in FT, you will need to find out why it does not work in WCS. Once you've done that, then definitely do as Coz suggested and get a Color DMD.

Test the voltages out of the DMD controller board or at the DMD. You should find one of the high voltages is low. ColorDMD will not need these high voltages so would not be a need to fix this unless you want to keep the original Plasma DMD in the game.

http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Testing_DMD_Controller_Power

Great. So now the question is: repair the board yourself, send it out for repair, or upgrade to the ColorDMD and not worry about it? Personally, I would go with ColorDMD, being that it is I have 10 of them. The games feel new to me again once I add the color display.

Best to replace all the components in the high voltage section to prevent future problems. Here are the parts required. https://www.greatplainselectronics.com/proddetail.asp?prod=WPC-HVP-KIT
You can use the part descriptions and buy from any electronic store/website.

Usually a HV rebuild is all that's required, but check your board to see how cooked it is. It might be too burnt to bother rebuilding

Although jumper wires may not look nice but do the job and it is best to put any on the backside if any are needed.

A huge problem with going the Color DMD route is that once you do that, you'll need another few hundred to do your FT.