Eight Ball Champ
Bally, 1985I have a Eight Ball Champ with the 6803 MPU. One of the thumper bumpers is not working and I think I traced it back to a blown Capacitor. I changed out the capacitor and when I ran the coil test, the new capacitor blew. Any ideas wat can cause the capacitor to blow? I replaced the coil as well, so I dint think its a bad coil. New to all this so please be patient. Thanks!
Quoted from Cheddar:bad diode on the coil is what I would check
The new coil I put in came with a new diode. Anything else I can check? My biggest worry is its something on the playfield, so even if i get a new replacement board, the same issue will happen to the new board. Are issues like this usually caused by something else on the MPU or by something on the playfield?
Quoted from Cheddar:Is the new coil wired correctly? The supply goes to the banded side of the diode
Yes I believe so. Its wired exactly the same as the other tumper bumper that works. Double yellow wire is on the banded side of the diode and single orange wire on the other. I used jumper wires from the working thumper bumper to the non working thumper bumper and ran the coil test, and they both fired. This tells me the coil is good. So how do i test if I'm getting the correct power to the non working thumper bumper? I'm not really sure what settings to use on my multi meter. Is it AC or DC voltage for the thumper bumpers? Sorry like I said I'm new to all this and when i try to read the schematics, its like trying to read a foreign language.
Quoted from Cheddar:Is the new coil wired correctly? The supply goes to the banded side of the diode
Sorry everyone, I think I had it wrong in my original post... I believe it's the Resistor on the 6803 Board that keeps burning out, not a capacitor! I warned you I was new at this.
Quoted from casher2006:Sorry everyone, I think I had it wrong in my original post... I believe it's the Resistor on the 6803 Board that keeps burning out, not a capacitor! I warned you I was new at this.
It is far more likely you have a shorted transistor for the coil, not a resistor. Pops are Q2 and Q3.
https://www.pinwiki.com/wiki/index.php?title=Bally_6803#Solenoid_Problems
Information here. Hopefully you have a multimeter.
Quoted from slochar:It is far more likely you have a shorted transistor for the coil, not a resistor. Pops are Q2 and Q3.
https://www.pinwiki.com/wiki/index.php?title=Bally_6803#Solenoid_Problems
Information here. Hopefully you have a multimeter.
Thanks! I did a voltage test at the coil and I'm not getting any voltage. does that mean its definitely something on the 6803 MPU board (resistor or Transistor) or can it still be something on the playfield?
Quoted from Brewchap:Can you post a picture of what your referring to?
Here is a picture of the Resistor that keeps burning out.
print_17_Bally_MPU6803_1_1_LI (2) (resized).jpgQuoted from casher2006:Here is a picture of the Resistor that keeps burning out.
R169 (330ohm resistor) burns by seeing too much voltage/current and the path to high voltage/current is through a shorted Q19 transistor (collector to base pins) or shorted C81 capacitor, that's causing R169 to see solenoid 43 volts. Note capacitor C81 is a 500V (or higher) capacitor.
Under normal circumstances, R169 only sees 2.3 volts when the transistor/coil is being activated.
Quoted from Quench:R169 (330ohm resistor) burns by seeing too much voltage/current and the path to high voltage/current is through a shorted Q19 transistor (collector to base pins) or shorted C81 capacitor, that's causing R169 to see solenoid 43 volts. Note capacitor C81 is a 500V (or higher) capacitor.
Under normal circumstances, R169 only sees 2.3 volts when the transistor/coil is being activated.
Thank you! I will try to replace the Q19 Transistor and C81 Cap.
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Middletown, DE