Well I know that work needs to be done on the boards to get this old fart running again. In the meantime I chucked in a Rottendog MPU327 so I can check out the rest of the machine.
Fired her up yesterday and  boots up good so power all OK.  Contacts on 1 and 4 lane need adjusting as they miss sometimes.  The 3rd bumper was locked due to closed contact (now fixed). 
Now for the biggest gripe, yes you guessed it, the Williams drop targets. They all worked fine when machine went to storage but now only 3 of 8 register points when dropped. I gave them a clean with Isocol but still no good. They are not worn so I am assuming they need to be bent forrward more to make contact. One target from the 3-bank now does not fall freely and I am assuming a spring is the problem.
Any tips with these type of drop targets?