Guardian Diverter on my Premium quit working properly after a couple of plays. Emailed STERN and got a call back within an hour. Great service.

Turns out they forgot to add the grease to the mechanism before it left the factory. Diverter was sticking trying to go up but could go down easily on it's own. $4 tube of white lithium grease from the hardware store and the game was back up and running.

The sarcophagus captive ball shot quit working on me after a couple of plays as well. Still gotta diagnose that one, but it hopefully looks like it's the switch gap issue that seems to be plaguing this mech.

Both my SW Pro and IMDN Premium has some of that visible "grain" as well. I can only see it when I'm actually looking for it, but it still sucks knowing it's there. At least it's better than ghosting inserts that will actually crack the clear and cause some real problems.

I was having the same issue with my ramp sticking in the up position. I added a little bit of white lithium grease as suggested earlier in the thread and it solved my problem (thanks for the suggestion pinside). I thought I'd provide a little more info to others in helping diagnose this issue:

- My ramp was moving up and down just fine if I was careful not to extend it too far, and just lift it up enough so that the other coil plate could engage the stop.
- When extending it just a little bit more (through the full stroke of the coil mech) I could feel the binding at the very end of the stroke.
- You can see in the picture where I've circled exactly where the ramp flap is rubbing against the upper ball guide.
- I added a small amount of grease just in this area and it's eliminated the sticking (although it will likely return).
- STERN Tech Support was very quick and responsive to offer a suggestion as well - the overall mech position can be adjusted slightly so that the flap doesn't rub against the ball guide. Seems like a lot of work right now considering the 10 second grease fix. I would venture to guess that bending the ramp flap up slightly would have the same effect.

Anyway, if your ramp mech is sticking throughout the full range of travel, then this likely isn't your problem, but if it sticks just a little at the very end, it appears to be clear what the hang up is.

Also, shortly after I got my ramp fixed I noticed the scoop stopped registering balls. After lifting the playfield the reason was obvious - the switch was completely off of the bracket and was very close to shorting across the high voltage coil. It had been installed with only one screw. For those owners out there, you may want to do a quick inspection and make sure that switch is indeed attached with two screws - I'm guessing I would have had much bigger issues if it had come loose and shorted with the coil...
IMDN_rubbing (resized).PNG

Registering your game online provides STERN with all the information they need to keep people up to speed on service bulletins, etc. - STERN just chooses not to.

http://sternpinball.com/warranty