Williams Black Knight (Williams, 1980) BK80: Rebuilding a Pop Bumper

[lothian]

Black Knight - 1980

With the help of this resource, I've determined that the lone pop bumper in my BK80 needs a complete rebuild. I some questions for those experienced with such things...

- Is there a "best in quality, completeness, and cost" pop bumper rebuild kit supplier I should consider?
- Is it prudent to replace the resistor, cap, and diode as part of a pop bumper rebuild?
- Why not replace the whole shebang with a shiny new pop bumper assembly, rather than rebuild the old with new parts?
- Does a purpose-designed LED pop bumper light kit exist that eliminates the need for a lamp holder entirely?

 

[AnonTet]

Welcome to PN.

I'll take the liberty to notify @pinballdaveh so he can have a look.

Do enjoy your stay here.

 

[pinballdaveh]

Welcome to PN.

I'll take the liberty to notify @pinballdaveh so he can have a look.

Do enjoy your stay here.

Jet bumpers as Williams calls them only need minimal maintenance. Coil sleeve is usually changed. Clean and inspect plunger, and links.
The gold contact switches need to be cleaned.
I use a folded dollar bill. Never use a file on gold switches.
Because of always having to be pulled to change a jet bumper skirt, light sockets have always been a problem. I don’t think anyone has come up with a quick fix yet.

 

[Pop Bumper Pete]

with any solenoid feature, they either work or they don't
if they don't work, then it usually is the switch/contacts
I agree with pinballdaveh, never file contacts, but i find rough cardboard to do the trick
take it apart and clean with alcohol, replace the coil sleeve if necessary
I do not know if that capacitor should be replaced or not (?)

 

[pinballdaveh]

with any solenoid feature, they either work or they don't
if they don't work, then it usually is the switch/contacts
I agree with pinballdaveh, never file contacts, but i find rough cardboard to do the trick
take it apart and clean with alcohol, replace the coil sleeve if necessary
I do not know if that capacitor should be replaced or not (?)

I would vote yes on the swap out of the electrolytic capacitor. After 45 years of life it’s due to be changed. The schematic shows 22 micro farads and the resistor at 100 ohms.
When the capacitor starts going bad, it might look like faulty switch closures, but maybe not all the time.