Bally SS Voltage Problems

[gwen]

We have Bally Playboy with no low voltage (have 179v + 237v), other test points read 0.  Have checked continuity on all wires from rectifier board J3 and checked ground.  All rectifier board points read correct.  Changed transformer and rectifier board and driver board from a perfectly good working Lost World into Playboy - same results as above, but work fine in Lost World!  What have I overlooked???  I thought continuity would have checked if the pins were buggered?  Thanks!!! ! ! !   

[Strangeways]

Couple of pointers ;

To measure the voltages from the power supply board, remove J1 and J3. Set the voltmeter to DC and connect the black probe to ground.

TP1 = 5Vdc
TP2 = 230Vdc
TP3 = 12Vdc
TP5 = 43Vdc

Change the meter to AV

TP4 = 7.3Vac

With the game off, remove the fuses and test each of them. Check the fuse holders, are they weak and brittle ?

If you have physically swapped the power supply and transformers, then you need to check the input voltage either at the varistor or E1 and E2 on the board. Sounds to me like a bad input voltage or gound. But if you are doing the tests with J1 and and J3, then something is dragging the voltage down.

[gwen]

 !@#Both power supply boards test correct,one from lost world is new.Does power go to mpu and enter sdb as low voltage?have read all i can and brain is fried

[Strangeways]

J1 goes to the playfield
J2 goes to the backbox

Isolate where the problem is by adding J1, then test the voltages - still good ? No = There's a short somewhere on the playfield

Do the same with J2

Something is dragging the power supply down.

I suspect a problem with the Solenoid driver board IF the power is dragged by adding J2.

Simple process of isolation, just follow the basics with this quick test and report back !

[gwen]

With both j1& j2 plugged in voltages are tp1=5.97
                                                       tp2=233
                                                       tp3=13.3
                                                       tp5=42.9
                                                       tp4=6.2vac
Driver board and rectifier board work perfect in lost world

[gwen]

 

Found problem- dirty connector at driver board j3 pin 12-the lesson continues,thanks for your assistance

[Strangeways]

Found problem- dirty connector at driver board j3 pin 12-the lesson continues,thanks for your assistance

Great job. Nothing more satisfying that repairing your own game. Enjoy playing it now !

 

[Boots]

Found problem- dirty connector at driver board j3 pin 12-the lesson continues,thanks for your assistance

This is one of the ones that always go bad with over heating.
Change the connector terminals on J3 and if they are bad the header pins on the SDB, this will solve a lot of these problems re-occuring.