Do you have any pictures of the mpu, particularly around the battery holder? Ballys of this era are notorious for battery damage. I doubt that the solenoids are defective. It's far more likely that you have issues on your PCBs. Luckily, newer versions of all of the dash 35 boards are available. Check out this site. I've had good luck with them in the past.

http://www.allteksystems.com

If it was me, I would just replace the mpu and the driver board rather than fiddling around with fixing the ones you have. Check your power supply out. Replacing it is more involved.

You're also fortunate that there is a lot of info out there in repairing these old ballys. Pinwiki has some great walkthroughs on fixing up these old games.

Power play is an awesome game. Good luck and have fun!

I have very little skill with soldering and desoldering on PCBs, so I tend to buy new ones if they're available. If you're good with a soldering iron, go for it. You'll also be a great asset around here to folks like me who can't do the soldering themselves.

Folks more knowledgable than I am about repairing dash 35 boards may want to chip in here but I think that mpu is a solid candidate for replacement. I totally know what you mean about not wanting to spend the money and I hope it can be repaired but if you find it can't, Alltek makes an excellent product.