Mystery switch 7 error on 1982 Bally

[DRD]

My vector won't go. It boots up properly. It does what I would expect, flashing lights, firing a few solenoids etc. the TILT light is not on, just game over and ball in play

But when you start a game it immediately goes into TILT and so quickly, that it doesn't even have time to fire a ball into the shooter lane. When in this TILT, the music plays, lights are on but it will not even react to the test button so needs power turning off to reset things

After turning on again and going into diagnostics, the displays look ok, the solenoids all fire, the sound seems ok to start with but does vary volume up and down a bit. Also during the sound test a number 7 is randomly appearing in the lower left scoreboard display ?????

On the switch test, it shows that switch 7 is closed. In my manual there is no switch 7!!!!!. 6 is credit button, 8 is push button (under panel in front). If I close switches lower than 7, these show so the diagnostic seems to work

Might anyone have any ideas what the problem is please ?

 

[replicas]

Did you disconnect a coil up on the coin door ?
Try reconnecting and get back.

 

[DRD]

Hi. Thanks for the suggestion.

I did disconnect a coil last night to test it. But it is back now and working

Something funny around the coin door is the logical place though, as this is where I was doing stuff, and it is about the right switch number

I wonder if it has a special extra tilt switch ? The condition if the game is like you had tilted it, and somehow the tilt switch remained closed so the game would not reset.

Could an extra tilt witch be on the unused switch 7 circuit. I did put card around all the other tilt switches I could see to eliminate them from enquiries

 

[Moonraker]

Hi. Thanks for the suggestion.

I did disconnect a coil last night to test it. But it is back now and working

Something funny around the coin door is the logical place though, as this is where I was doing stuff, and it is about the right switch number

I wonder if it has a special extra tilt switch ? The condition if the game is like you had tilted it, and somehow the tilt switch remained closed so the game would not reset.

Could an extra tilt witch be on the unused switch 7 circuit. I did put card around all the other tilt switches I could see to eliminate them from enquiries

Which switch is the slam tilt that is normally on the coin door...? It sounds like it might need adjusting...

 

[DRD]

Thanks, The slam tilt on the door is ok. I can test it to produce a slam tilt.

The solenoid on the door I tested last night is also ok, as when maximum credits are reached, it blocks the coin mech as it should. And it energises to allow coins in when below max credit

The 3 coin switches are all working ok too

 

[Nedreud]

Check for duff diodes. Check all switches have diodes! Sometimes they get cut off and although a single switch press will work without them you get some very strange results when multiple switches on the same row/column are pressed! Definitely check for shorts, particularly on the door switches. If I recall correctly there's a connector for the wiring to the door so you can completely remove all those switches from the equation.

 

[lukewells]

If you are getting an instant Tilt, and the switch test is showing that 7 is stuck on, then you have a short on that switch row, so the game will be seeing a combination of 7,15 (tilt), 23, 31, 39, 47 as on

39 is a slingshot, and that is a common place to find a short, so i'd check there first. Its possible the diode on one of those switches is shorted and/or one of those switches is physically stuck on.

Check each of them with an ohm meter. Measure the phsical switch itself and also check for a short across the diode on each of those switches

 

[DRD]

Thanks for all the suggestions.

Lukewells was dead right. There was a short on the switch row, on a drop target . I now need to read up what switch rows do. A diode was touching a bare wire. This game has a lot of bare wires under it, I think it was made this way

The switch test now comes back clean, with no rogue hits

Unfortunately I think that this has now killed a transistor. Or it is a coincidence of timing.

Solenoid 2 is energised as soon as you turn the game on and it blows a fuse that is unmarked but located to the underside of the playfield. It had a 1 amp fuse in. This takes all the solenoids down bar 3 of them. This game has a solenoid expander board as there are so many.

Is my practical starting point replacing transistor q2 on the solenoid driver board ? The power transistors are marked 126m 2n6045

Thanks

 

[lukewells]

The 1amp fuse under the playfield does protect all low power coils, the high power coils are directly fused by the rectifier board.

Yes go ahead and replace the transistor for coil 2. But get a TIP102 transisor, these are more common, cheaper and higher rated.

Also replace the diode on coil 2 at the same time. I've found in Bally/Stern games they often fail at the same time, if you replace one without the other it will just fail again very soon after.

 

[DRD]

Thanks again Luke. I have added you to the growing list of folk I owe a drink to! When vector is sorted it will be accompanying me to NERG so if I see you there I will get you one in.

 

[lukewells]

No problem mate, good luck!

 

[cooldan]

If you are getting an instant Tilt, and the switch test is showing that 7 is stuck on, then you have a short on that switch row, so the game will be seeing a combination of 7,15 (tilt), 23, 31, 39, 47 as on

39 is a slingshot, and that is a common place to find a short, so i'd check there first. Its possible the diode on one of those switches is shorted and/or one of those switches is physically stuck on.

Check each of them with an ohm meter. Measure the phsical switch itself and also check for a short across the diode on each of those switches

impressive