These b*stards hate me - they REALLY hate me !

[Wotto]

Man

I reckon I am the ONLY person on this planet that can have a PERFECTLY working game ( CFTBL ) and simply change a flasher bulb on it, turn it back on and have random switches now not working.

I mean that MUST be bad karma coming back at me surely
Sometimes I TRULY HATE these games

[Wotto]

Update - it is ONE row of switches that have died.
What the hell could I have done?

[Pop Bumper Pete]

Update - it is ONE row of switches that have died.
What the hell could I have done?

broken a wire?
Did that with TDK, most of a row was out, looked at what worked and what did not, found the broken wire

[swinks]

A while ago I had a unusual problem when I did a similar thing on my cftbl. When you lift the playfield and put it back in the plunger rod comes very close to the ball eject solunoid that shoots the ball back up to the playfield into the right lane. I broke the wire connector off the solunoid base but not the wire to the solenoid still worked but knocked out the GI lighting because of the bracket it was shorting out to. It could be a similar thing but touching something else - worth checking.

[Ant68]

Sort somewhere  

[Replay]

short and maybe blown fuse ??

[Wotto]

Update

Its all of 'column' 4.

No broken wires - I looked real hard.

No shorts ( that I can see ) - that would be 2 parts of one of the switches touching each other that otherwise are not meant to OR another component (like a Gi bulb holder etc ) touching one of the switches in the column / components of the switch - correct?

Fuses checked - seemed good but replaced just in case.

 



SURELY this cant be the result of me placing 2 x '89' style LED flashers in place of standard  '89' style globes ( which I have done with success before )

Next 

[Wotto]

Uh oh 

Just found this at RGP - could this be me now 

> I have a '92 Bally Creature from the Black Lagoon and Column 4 on the switch
> matrix is dead.  I've done some basic checking and I'm thinking that I may have
> blown a line on the LN2803 IC.  I was changing a right slingshot GI bulb near
> one of the switches on Column 4 (the right slingshot switch!) of the matrix and
> think I may have shorted the switch and blown a line on the 2803.

Yep ... common problem.

If your U20 (the ULN 2803) isn't already in a socket, make sure you put
one in prior to replacement -- those chips fail often.  Newer CPU's
(the security and WPC 95 cpu) put 'em in sockets at the factory.

[Ant68]

How'd you go , have you sorted it out ?

Uh oh 

Just found this at RGP - could this be me now 

> I have a '92 Bally Creature from the Black Lagoon and Column 4 on the switch
> matrix is dead.  I've done some basic checking and I'm thinking that I may have
> blown a line on the LN2803 IC.  I was changing a right slingshot GI bulb near
> one of the switches on Column 4 (the right slingshot switch!) of the matrix and
> think I may have shorted the switch and blown a line on the 2803.

Yep ... common problem.

If your U20 (the ULN 2803) isn't already in a socket, make sure you put
one in prior to replacement -- those chips fail often.  Newer CPU's
(the security and WPC 95 cpu) put 'em in sockets at the factory.

[Wotto]

Nope 

[goodolddays]

Hey Wotto .

I discovered Mark C sells the switch matrix chip for $2.95.

Looked at my CFTBL before and U20 on the CPU baord on mine (its above where the switch row and columns plug in ) is socketed so easy to swap this chip for me . Does your's have a socket at U20 ?

[Wotto]

Hey Wotto .
Does your's have a socket at U20 ?

Of course mine doesnt 
But I do have a spare ULN2803A chip

[Marty Machine]

Ok, so it looks like it *might* be the chip and a known problem...

But, for the sake or proving things, i need to ask a silly question:
Did you revert back to just using normal globes or no globes in those 2 sockets and see if it restores the switch matrix?

Those flasher globes have varying characteristics that make them work on some games (chips) but not on others.

something to try while your soldering iron warms up  ;-)

MM.

[ddstoys]

Quick way to check if it's the chip wotto.  While its in switch test remove the plugs at the bottom of the cpu

[TUF-427]

My Getaway blew the U20 a few times took me awhile to find the real cause,

the dissapear post coil winding had rubbed thru the wire varnish making its bracket and post 50v,

I think when the ball was touching the post made the wire ramp 50v and found its way into the switch matrix somehow!!!!

Real Pita it would blow the U20 and the next chip in the line also....