WILLIAMS COILS ALL PULS WHEN FIRST SWITCHED ON?????

[ddstoys]

After some info.  Had firepower running 100%  turned it on the other day and all the coils pulsed and blew the fuse replaced the fuse an sure enough same thing happened this happenr regardless if the switches are plugged in or not.


  Ive narrowed it down to a driver board fault by testing with another driver board.

  Ive swapped the PIA with a known working one


  Any suggestions to where i should look?


 

[Retropin]

All coils pulse??  You have a short to ground on solenoid power path, OR solenoid switch input path... if all switch inputs go through 1 chip, id be testing the function of this first, failing that, disconnect solenoid connectors and test inputs and ground for continuity.. you should read open

[ddstoys]

Thanks for the reply gav.  Ended up being a single 7408 ic1.   Replaced a few ratty looking chips testing the board each chip so I knew what the problem was.

[FirePower]

It's good you've solved the problem and for interest I think another reason for this is tied up with a failed blanking signal.
One of the online WMS guides has a bit to say about this I think - from memory it's talked about on  Clays guide and the other one the by a bloke called Mark.
 

[Boots]

Thanks for the reply gav.  Ended up being a single 7408 ic1.   Replaced a few ratty looking chips testing the board each chip so I knew what the problem was.

I had the same problem with my Timewarp, funny thing was the chips tested ok soldered to the board, but were clearly faulty when tested off the board.
Has anyone else seen that before?

Boots