righto then. at the risk of being pushy I do have the board out at the moment (first time I've done one of these boards which is why I'm asking). i have rebuilt ALL of the HV components, looks like one of the 1/2 watt resistors cooked a while back (before the replaced upgrade). i'll do the ground upgrades on the 2 big caps and tie TP1 and TP3. i will do the headers and connectors, I am upgrading C23 to 15K mf (EBD has 3 flippers). I have a replacement flipper relay but wasn't going to replace it because the other one is working fine (should I ?) - are these a common cause of failure? appreciate your comments guys if there is anything else you recommend! cheers s
to any noobs reading this thread, have a go!, it's pretty satisfying to be able to fix your game from top to bottom. if you haven't done much/any soldering do an online tutorial and maybe practice on a cheap jaycar kit or something before tackling a pin board. the one main thing i have learned is you should spend more care and time on component removal than component addition. Those traces are hard to repair if you carelessly break them removing components (get a good pair of tiny sidecutters and take no risks 'pulling' components - cut them off!). also 'test' your work with a MM before connecting the power! test for shorts if it looks like a couple of joints may be too close and make sure your connections are tight.
You should be right Stu. The best way to check a TIP102 is to set the MM to "continuity" and then check for any shorts. Testing them this way is the easiest, and when you switch the game on, you won't have any locked on coils caused by the transistors. Measuring resistance to ground will give you different readings as you are measuring the "circuit", not the component. There are other components influencing the reading as the other components can have a 10% tolerance - like resistors for example..
