Williams Solved Flash (Williams, 1979) Switch matrix problem

[Cirom]

I have a Williams flash pinball and been having problems with some of the switches. Using the switch matrix I found that when I trigger a switch on column 4 it would then trigger all switches on that row.diodes and wiring all look fine could it be something on the board? Which are fairly new btw.

 

[pinballdaveh]

switch column 4 problem. switch columns connect to connector 2P2 (upper top right connector on driver board) . column 4 wire grn-yel connects to pin 6 . pin 1 is on top counting down , pin 4 is key. pin 6 is controlled by IC17 sn7406 hex inverter. both IC17 and IC18 controll switch column drives and are both sn7406. if all wiring and diodes check out fine i would change U17 first if not both U17 and U18. after de-soldering and removing chip(s) install 14pin socket(s) to avoid new chips from being soldered in , and easy replacement if they go bad again. be sure to install chips with the dot or dimple facing in proper direction , if put in backwards damage might occur to the board.

 

[faralos]

I also own a Flash pin and these sites come in handy
http://www.edcheung.com/album/album06/Pinball/flash.htm
http://www.pinrepair.com/restore/index1.htm
that second site (pinrepair)also has two other parts to it
just click on them to call them up also
and I pulled this off the IPDB
http://www.speedyshare.com/asKcG/Williams-1979-Flash-Manual.zip
hope some of this comes in handy for ya'

 

[Cirom]

You were right pinballdaveh I changed the u17 chip and works like a dream once again.i can stop stressing over it now lol.
Thanks for links too faralos they'll come in handy.
Much appreciated guys

 

[faralos]

out of curiosity how does your play field fare?
Are the play field lenses okay? Mine are all warped
and stick up over the play field surface
I have yet to get any of them out since a hair dryer ain't touching them
Any suggestions? I have NO money to buy a heat gun
so that's out of the question

 

[Cirom]

My playfield is pretty good apart from one of the arrows pointing to the 5 drop target. It sticks up abit but in to scared to do anything with it incase I crack it. This is the first time I've heard of using a heat gun maybe I'll give it ago. Do you know a website where you can buy new plastic playfield inserts?

 

[faralos]

this is the only site I can find that sells the complete Flash Plastics set
http://www.marcospecialties.com/pinball-parts/265?S_CAT1=PFLD
hope it helps ya'