Stuck on coil - help

[Lance]

Just got a CV , it has a stuck on coil at powerup. Coil is all burnt , I have disconnected it so machine plays ok for rest , just the Diverter assembly doesnt work
.
its the diverter coil, J133-2 , j116-7 and Q66 in manual.

I think that means a board repair. Anyone know anyone that could do this and check board over. Would like repair to look original if poss.

Many thanks

 

[Spandangler]

Hi Lance. Yes the transistor will have blown. Easy to see in manual which one It is. Now trust me (from a man who struggles to put up a shelf) even I have changed these. But if you’re still not confident there are plenty of people who will. @pinballmania @myPinballs @lukewells

 

[Lance]

Thanks will pm them, I did attempt a board repair once, I got told off, always best to leave it to the experts.

 

[Moonraker]

You've already said in your first post - it's transistor Q66 that you need to change...

 

[stoptap]

You've already said in your first post - it's transistor Q66 that you need to change...

Occaisionally the pre-driver transistor. I’ve seen both need replacing at the same time too.

 

[cooldan]

Go on have a go, it’s not so hard:

1 Find Q66 on the board
2 Snip the 3 legs as long as possible
3 desolder (remove) the legs
4 clean holes up
5 put new transistor in
6 solder the three legs in
7 use a meter to check no shorts
8 replace the coil

Always do the coil last, as a buggered transistor will just fry the new coil again but not vice versa.

 

[Jay Walker]

A burnt-out solenoid can blow a new transistor. I've had it happen, and had to replace the device again, along with the coil. A new coil might lock On if the transistor, relay or whatever is shorted, but it would be okay if the power was turned Off straight away.

 

[myPinballs]

This issue is now fixed. The problem was actually Q86 which is the hold diverter control and also U8 which is the latch ic for the 8 'flipper' devices.

What i think happened here is the output side of U8 for the diverter hold drive partially failed internally which locked the coil on. This then burned the coil up and killed the Q86 transistor. Not sure if the code on the game holds the diverter on for ages or not, but if so could be a weak spot over long periods of time (25 years etc).

The coil must be changed before the fixed board is put back in!

Jim

 

[Lance]

Brilliant Jim, many thanks . Always best to go to an expert on this stuff.