95% up and running. Depends on one's definition of up and running.
I just got back from there, and personally, I'd advise all players and enthusiasts to AVOID the PHOF completely unless you are ONLY going solely for the newest of new Sterns or the EM's.

I played roughly 40 titles that were SS1978- DMD1998.
39 WERE IN REPREHENSIBLE SHAPE....QBert Qubes played well.
This is not an exaggeration.
Not another single machine worked right, and not just a little bad, these were ALL really, unplayable bad.

Tim Arnold should be ashamed of himself and quit the trade immediately.
As a former operator in the heyday, he has no excuse whatsoever for having a floor full of such garbage.
Pinball is in a resurgence, and op's like this give the hobby a terrible reputation.
He is ripping people off, proceeds going to charity of not.
I am disgusted and will not return, and I implore others to do the same.

I never make waves on Pinside - haven't the time or desire for starting controversy.
But...I've always stuck up for his operation when others say it stinks.
No longer.

A few, yes.

*Sega Star Wars Tril:
Top saucer inoperable, multiball mode inoperable, ramp hits not registering.
*DE Jurassic Park:
Ghost drains, dead ball kicker, more problems I truthfully do not remember.
*DE 88/89 Playboy:
Top saucer inoperable, multiball not functional, ghost drains.
*Safe cracker.
Ball stuck repeatedly when top drop down on left side 3 bank, spinner dead, pops weak.
*Twilight Zone
Skill shot inactive(ball got stuck there also), rocket did not register hitchhiker, spiral electro mags out.
*Hoe Down 1978 Allied leisure
Left and right drop targs literally severed at playfield level, so they never came up. Weak pop, dead pop.
*Bugs Bunny BB91
Just on with no boot up, no display activity or any life signs for that matter, except basic power.
*Dr Who
Game was on, looked good to go. Press the blinking credit button, and nothing booted-- it just stated on the DMD "Out of Order" (I never even knew this was possible).
*South Park
Entire game just sucked, just plain miserable with damage present in toilet stationary target and other places (Kenny).

I really wish I could remember more, but after a short time I was walking away after one or two balls and just went back to Wedgehead row where I could at least salvage the bus ride and waste of the day.
It was really disgusting in there too.
Dirty, broken parts everywhere, stupid notes on video games like - I can't get parts for Donkey Kong and you will be thrown out if you are nasty with the game.
Really - no parts? They only made, what - 150,000 original DK's and God knows how many hack clones.

It was that bad.

Possibly, but a bigger notice matter: He was, about a year ago, supposedly looking for a partner (one with technical experience, no doubt) to ease the burden of the day to day.
Has to be a lot of work, fair enough.
But that's why you give SOME to charity, and keep 75% of the revenue both to pay rent, live on, and very importantly: UP KEEP the games.