Star Trek
Bally, 1979No coils are working. All fuses are good (on solenoid driver, under playfield and on rectifier board)
All test points on the rectifier board are good.
TP3 on on the solenoid driver board is 0.01
TP5 is 12.8
I found this:
But it doesn't say what to do if the measurements are off... I put in a known working solenoid driver board and all the solenoids except for the flippers worked. So i believe the problem to be on the board. What should i check?
Also, the displays are all only showing one digit with both the original and the working solenoid driver board installed. I think the display issue is separate from no coils working
I can hear the relay on the solenoid driver click with the working board, but it does not click with the original. Where should I direct my attention?
Perhaps a cracked header pin on the original solenoid driver board?
Double check for any cracked header pins and reflow the solder on any that don't look good.
Super weird but now the coils started working Except for the flippers. I now get 5V on TP3 but still only 12.8 on TP5. I'll take another look at the header pins.
Edit: Annnd not working again lol
header pins look fine.
What does low voltage on TP5 point to, knowing that the problem is on the board somewhere?
Check all the connector pins and header pins on :
J3 on the Transformer board
J3 on the Solenoid board - especially pins 13 and 25. The +5vdc is generated on the board, loops out on a wire and back to power the onboard solenoid related logic chips.
Could be a flaky connection on one of those.
Need a solid and constant +5vdc on the solenoid board for any of the solenoids to fire.
If that all checks out, have you measured voltage at the solenoids? Want to see about +43vdc constantly at the solenoids.
Quoted from pinlink:What does low voltage on TP5 point to
TP5 on the solenoid board? +12.8vdc is normal for there, it's listed as +11.9vdc on the schematic.
Quoted from pinlink:What does low voltage on TP5 point to
12.8V is a bit low. It could be capacitor C23 potentially failing or it's ground connection is poor. Does the solenoid driver board have the SDB ground mods?
It typically reads somewhere between 14 to 16.5 volts at TP5. Ignore the 11.9V on the solenoid driver board schematic - it's an error. The rectifier board will read 11.9 volts when the solenoid driver board is NOT connected (i.e. C23 is not in circuit and filtering that DC supply rail). When capacitor C23 is in circuit and storing energy, that voltage rail rises.
Set your meter to AC voltage and measure the ripple voltage across the capacitor (meter leads go on each side of the C23 capacitor). Should be around 0.2 - 0.3 volts from memory.
Quoted from pinlink:No coils are working...
TP3 on on the solenoid driver board is 0.01
Did you follow the instruction in the attachment of your first post? Spybryon also mentioned it in the previous post:
Quoted from Quench:Set your meter to AC voltage and measure the ripple voltage across the capacitor (meter leads go on each side of the C23 capacitor). Should be around 0.2 - 0.3 volts from memory.
C23 is measuring 30.6 when meter is set to AC
Quoted from Quench:Does the solenoid driver board have the SDB ground mods?
honestly not sure
Quoted from Quench:Did you follow the instruction in the attachment of your first post? Spybryon also mentioned it in the previous post:
yes, that connection is good
OK so TP5 is testing good then. It's TP3 that I should be concerned with.
TP1 is 5.2V but still TP3 is 0.01
Quoted from Spybryon:If that all checks out, have you measured voltage at the solenoids? Want to see about +43vdc constantly at the solenoids.
Yes I do have voltage at the solenoids. About 41.8V
I even checked for continuity via the back of the SD board on the header pins at J3 pins 13 and 25 when it's connected and it tested good.
Anything else that could cause TP3 to read 0V?
Quoted from pinlink:TP1 is 5.2V but still TP3 is 0.01
Quoted from pinlink:yes, that connection is good
The voltages you're getting at TP1 and TP3 suggest otherwise about that connection. Remove that loop wire between pin 13 and pin 25 and closely inspect the crimps. Maybe the wire insulation wasn't stripped enough on one end, or the crimp terminal is loose/broken.
Quoted from Quench:The voltages you're getting at TP1 and TP3 suggest otherwise about that connection. Remove that loop wire between pin 13 and pin 25 and closely inspect the crimps. Maybe the wire insulation wasn't stripped enough on one end, or the crimp terminal is loose/broken.
Thanks Quench, I'll take a closer look again, but when I tested it with my meter the connection is good. Also when I put a working SD board in, everything works as it should which seems to suggest that connection is good?
With the machine OFF, how much resistance do you measure between TP1 and TP3? It should be about zero ohms.
Quoted from Quench:With the machine OFF, how much resistance do you measure between TP1 and TP3? It should be about zero ohms.
Assuming I have the DMM set correctly, I am getting 5.16
307E1954-6F5D-4F65-8669-0F378EF80E3A (resized).jpeg
Quoted from pinlink:Assuming I have the DMM set correctly, I am getting 5.16
Put the meter on the lowest scale of 200 ohms when checking for continuity.
Quoted from pinlink:Thanks. When meter is on 200 I get this:
That's an open circuit.
A closed circuit of zero ohms is the same as touching the meter probes together.
Check those wire crimps.
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New Brighton, PA