GTB Sys 1 Playfield feature lights not working

[Brettski]

Hi all,

 I have an issue with the playfield feature lights not working on my Cleopatra. It has just been rebuilt and all other GI is working good on playfield and backbox. When I do a lamps test only the Extra Ball light between the flippers flashes plus the backbox lights but no playfield bonus lights etc. I have repinned all the connectors but realise that can still be an issue, I am using a Pascal 4in1 board. The ground for the extra ball lamp is coming directly from the loom and not from the daisy chained ground the others work from so I ran a wire from the extra ball ground to the daisy chained ground on the feature lights and they worked!. So this tells me it's a ground wire or connector. Can anyone tell me which connector pin relates to the ground for the playfield feature lamps? I know I am close and those crimps are buggers to get out so going straight to the culprit would be nice.

Any help appreciated.

Cheers: Brettski... :)

[Boots]

Hi all,

 I have an issue with the playfield feature lights not working on my Cleopatra. It has just been rebuilt and all other GI is working good on playfield and backbox. When I do a lamps test only the Extra Ball light between the flippers flashes plus the backbox lights but no playfield bonus lights etc. I have repinned all the connectors but realise that can still be an issue, I am using a Pascal 4in1 board. The ground for the extra ball lamp is coming directly from the loom and not from the daisy chained ground the others work from so I ran a wire from the extra ball ground to the daisy chained ground on the feature lights and they worked!. So this tells me it's a ground wire or connector. Can anyone tell me which connector pin relates to the ground for the playfield feature lamps? I know I am close and those crimps are buggers to get out so going straight to the culprit would be nice.

Any help appreciated.

Cheers: Brettski... :)

You mean the power to the extra ball lamp?
The driver board grounds each lamp to light it, the power is there all the time.
Sounds like you have a break somewhere in the power
The power for the lamps comes from the power board in the lower cabinet, there is a connector there that supplies the power

[Brettski]

Thanks Chris,

Basically by connecting the common from the extra ball light to the common on the rest of the feature lamps they all work as they are daisy chained by the un-insulated wire going around under the playfield.

If I remove the feature lamp fuse on the tranny board then even the extra ball won't work so power is coming from the bottom of the cabinet, problem seems to be a break in the common coming from the board connector or broken wire.

They have a common wire and a individual wire, it's the common wire where the ground is lost.

Geez I have a hard time explaining my self! but what I really need to know is which pin on the A3 connectors supply's the common ground to the feature lamps?

Cheers: Brettski... :)

[Retropin]

The uninsulated wire under the PF is your 6V supply... THIS is basically your common.
If you attach a wire to one of the earths on the machine and touch the other side of the lamp with it, then if it lights up you have lost the signal that takes the lamp to ground.
If it doesn't light up then you have lost your 6V supply and more than likely have a break somewhere in the uninsulated wiring

[Brettski]

Ahhh I get it now, i had it arse about so I am not looking at connectors in the backbox, I need to go to the bottom board and look at the bridge rectifier and the wires there. Can a faulty bridge rectifier create this kind of fault without blowing a fuse?

Thanks guys for explaining it to me. :)

It's a magical mystery tour but getting closer I believe.

Cheers: Brettski... :)

[Retropin]

Ahhh I get it now, i had it arse about so I am not looking at connectors in the backbox, I need to go to the bottom board and look at the bridge rectifier and the wires there. Can a faulty bridge rectifier create this kind of fault without blowing a fuse?

Thanks guys for explaining it to me. :)

It's a magical mystery tour but getting closer I believe.

Cheers: Brettski... :)

Got nothing to do with bridge rectifiers.. don't go poking around there as these are to make the 240V AC into DC. The lamps work off 6VAC which comes direct from the transformer via a connector as Boots said. First thing you need to do is make sure the braided wire that runs through the pf actually has 6V on it where the lamps are not working. With CPU controlled lamps, they have 6VAC on both sides of the lamp at all times. When the CPU wants to trigger a lamp one side is run to ground via a transistor or similar.
Your CPU may well be working fine but if you don't have the 6V then there is nothing to run to ground. That's why I suggested to take a wire from an earth source and touch the signal side of the lamp with it... if the 6V is present then it will light up. If this happens then you have a CPU fault.
If nothing happens then you more likely have broken line in the braided wire. Once this is determined, follow the braid to each lamp until you hit a working one and right there is where you will find the broken link

[Brettski]

Ok I did what you said and used a wire from the ground to a lamp and nothing, I figured that because when I jump it from the extra ball lamp power it works that the playfield circuit is complete so I went down the path of elimination and got it to work, it was either dirty contacts in the tilt relay which I cleaned or the block connectors linking the transformer power to the playfield, I pulled them apart and back together a few times and wriggled the wires in the connectors so it was one of the two, I put my money on the tilt relay dirty contact myself but you guys might have a better idea. Anyway thanks to Boots and Retropin it is all systems go!!

Well done and really appreciated your help on this one..

BTW I need to replace a couple of diodes on some coils, what type do I need and can I get them from Jaycar?

Cheers: Brettski... :) 

[Mr Pinbologist]

The coil diodes are 1N4007 and yes Jaycar have them

[Boots]

1N4004 will also do
Buy a big pack, you will always use them.