It is outgassing. Go LED and dump your HV section all-together, one less thing to worry about fixing in the future. X-Pin makes nice displays. I've bought several over the years.

Agree - best bet if it is for the long run

http://xpinpinball.com/product/xp-wms12739/
$200
You'll be very happy and glad you did this instead of plasma.

XPin looks the best in my opinion. The tinted vinyl overlay they include hides the unlit LED segments and makes it look like a gas display. They also have excellent after-purchase support.

i replaced my bop with the xpin and it is great, highly recommended. im pretty sure bop and funhouse used the same display

This has always been my biggest gripe with LED displays--the unlit displays always stood out and looked horrible. I'm really glad this is an option. Might have to update my aging displays now.

Actually, a question I'd like to add to the OP's discussion, how much of a strain do these replacement LED units place on the WPC and System 11 power supplies? I only ask, because I know that the Bally units for their -17/-35 boards can add up to an extra amp of current, nearly maxing out the poor 5 volt regulator.

The xpin stuff looks sharp, is well designed, and is a cinch to install. They're great. I swear I don't work for them.

I believe the bally displays run off the original HV power. I may be wrong there, but it looks like they are pin for pin compatible, so plug and play. Maybe they step down the HV to whatever they need to run. Or maybe they just don't use the HV pins on the edge connectors and are powered by the same logic power rail. Either way, I doubt the draw is significant or they wouldn't be selling them.

Just read some info. Looks like they do draw from the +5v, but have very low power consumption. 8 segments per display block, 6 or 7 blocks. With all turned on per a display, if they're drawing about 15mA per segment (which is a pretty liberal estimate probably), that's 120mA per fully lit block, or 840 for the entire display. But remember these displays are strobed, so the maximum draw it would ever have with the decoder ICs can't be more than an amp at any given moment, and that is with all display segments on at once. The strobing effect itself also uses less power, much like PWM, so it is off more than it is on. I dunno what the refresh cycle is on the bally games, but I wouldn't be surprised if it uses 1/2 of what I estimated the max to be simply due to the design.

Awesome. Thanks for your information!

NP. What game were you gonna drop these into?

I'm planning on a medium-high end restoration of my Whirlwind when I get my playfield back from Neo. The current displays aren't bad, but you can see burn in and weak comma segments starting to appear. Figured I'd drop in a new set of displays while I've got the thing in pieces.

Go LED. I do it to all my games I can. I like being able to cut off the high voltage of the boards. Saves a bunch of power and the displays practically last forever.

yea, i just placed a big order with Xpin as well again.