Williams Solved PIN·BOT (Williams, 1986) "Eyes" Flash Lamps Burning Out...

[Coil_Smoke]

:idea: Pin-bot Has two flash lamps under the visor :idea:. They are referred to as the "EYES". They do get heavy use especially during "attract" mode. They seem quite bright(like almost blue) and blow in a matter of days to a week or two. Even solid state LED's go out after about a month ! Is there a higher voltage lamp that will fit these sockets in my game? Or Is something else amiss ?

 

[faralos]

Is the fuse for them the correct size? Check the manual for the right fuses
or try to make the actual sockets hang lower from the play fields under side
to cool them down a bit by keeping them from maybe touching the undersides plastic light covers.
Odd that the new LED's also burn out though never thought they could so quick!

 

[hgpinball]

The lamps
#9 (robot face, 2 lamps in backbox),
#10 (visor right, 3 lamps) and
#18 (visor left, 3 lamps)
on the insert board and the playfield (reference: Pin*Bot manual pg. 26 and 50) are not type #89 (=12...13V) but #1251 (=28V) lamps. The #1251 are driven directly by the voltage SOL.B+ of approx. 30V and they must not be replaced by #89 lamps! These will shine very brightly but also burn out very quickly. (All switched #89 flashers are driven via resistor boards under the playfield, these divide the SOL.B+ voltage to provide approx. 12...13V for the #89 flashers.)

To replace these #1251 lamps by 12V-LED flashers I used several 7812 voltage regulators under the playfield and behind the insert board to lower the SOL.B+ to 12V for the LED flashers. (Instead of that you may add a matching resistor to form a voltage divider)

To replace the #89 flasher lamps by LED flashers you'll have to remove the 330-Ohm resistors on the resistor boards and replace the 5-Ohm resistors because their value matches the #89 lamps' resistance to make a correct voltage divider. LED flashers have a higher resistance and need a resistor of around 50 Ohm *) instead of 5 Ohm on the resistor board.

All flashers are wired in parallel pairs, except the 'eyes' #10 and #18, which are triples.

See attachment for the location of the flashers.

*)This value is approximated and has to be calculated from the LED flashers resistance to form a correct voltage divider!

 

[Coil_Smoke]

#1251 28 Volt Lamps...

Thanks so much for the detailed response. I thought the measured 28v in those sockets must have been a defect. I have some #1251 lamps on order and will report back when I have given them some use.