Bottom board removal is not difficult, with the board setting on a table, with a good light and comfortable chair switch adjustment is accessible.

I was once hesitant to mess with motor switch stacks but it is like anything else on these machines, logical.

Hi timab2000

Can you just clarify what actually happens...sounds like the bonus counts up ok as you play.

When the ball drains, do the lights count back down to the 1000 lamp ok, and its just you are not racking up the bonus score?

You are correct, that switch that scores 1000 is the one that score each 1000 (but there are few other switches in the circuit, lets leave those for now).

Is it clean? Sometimes when you press with your fingers it gets a better contact than when the stepper activates it. I'd start with that before we delve deeper - wipe with alcohol on a cotton bud, then a flex stone (if you don't have one then a gentle 400 grit sandpaper or similar, then one more quick wipe with alcohol. If that switch is ok, there's a couple of other we can move onto - I'd look at score motor 2C (I can post relevant schematic piece later if needed to explain)

You asked about getting to score motor switches, you can lift the score motor by undoing the cotter pin. Capture (resized).JPG This can help sometimes. All you need to know is here in the holy texts : http://www.pinrepair.com/em/index3.htm#motor (plus how to read schematics, etc, etc, etc)

The post that curriedog pointed out is the post that opens the circuit when the bonus has finished counting down (so it stops). Again, comes down to exactly what is occurring on your machine...

Will it score any bonus if you light the A and/or B lights?

Oops, too much Templeton last night, that switch is only for counting up, not down - my mistake, sorry timab2000 . I have taken a closer look and here's my thoughts (by the way, good question from HowardR as that may be handy as we troubleshoot further).

So the circuit in question I believe is this:
Capture (resized).JPG

For the 1000 to score, the 1000 point relay has to fire (upper most blue arrow). For it to fire then, assuming A or B lights not lit then the following switches are relevant (working down my blue arrows):

- Switch on Bonus Score relay, wires are 81 (Black with red trace) and 58 so White with Black trace - you get the idea
(I have a photo below on the location of the bonus score relay). When then bonus is counting down, this relay should be engaged - you can visually check that.

- Switch on ball index relay, wires 58 and 48 (photo below again) - index relay should be engaged when ball drains

- Switch on B relay wires 48 and 20 - which is normally closed (unless B light on, but lets assume its off for now)

- then just to make it interesting, you have to follow the red marker up to the top, and finally score motor 2C, here's how to find that:

sc (resized).jpg

Here's the location of the relays - you are correct, they are not easy to get to! Don't forget it may help to lift and pull the playfield forward (remove ball first!) until it drops into the side cut outs and then you can tip it all the way back to rest on headboard - but be careful!
InkedInkedthumbnail_IMG_6913_LI (resized).jpg

Inkedthumbnail_IMG_6914_LI (resized).jpg The lower photo highlights the "B" relay.

I would start with the score motor 2C - they are often at fault and its the easiest one to get to! Good luck!