I don't know if it's rare. Williams made a lot of test equipment for distributors, for each new system that came out.

Other manufacturers made them too.

LTG : )

Here is a bunch of different ones :

http://elkhartpinball.com/httpelkhartpinball.comtest.htm

LTG : )

It's a system 9-11 test fixture (to test the boards from system 9-11 games)

https://www.pinwiki.com/wiki/index.php/Pinball_Test_Fixtures#System_9-11_Test_fixture

It's relatively difficult to find one for sale now. I haven't seen one pop up in years. People like to hang onto them when the get them.

I'd say if you can get it for $750 or less, that would be a screaming deal.

Note that these fixture are really only useful for people who frequently do a lot of board repairs. The average game owner isn't really going to find these large test fixtures all that useful.

It looks like the proprietary testing boards used for this kit are not here. They would be present at the top if they were. Good luck finding them

As far as I was aware, there weren't any proprietary boards in this fixture.

Standard power supply inside, then a standard boardset on top (master display board, MPU, sound board), but with a special test ROM for the MPU.

Here's some photos I've collected of this type of fixture:
11tester1 (resized).png11tester2 (resized).png11tester3 (resized).png11tester4 (resized).png11tester5 (resized).png11tester6 (resized).pngIMG-0103 (resized).jpgc39320b0a16ee789961435878d206d81915eddb3 (resized).jpgc879d1ee0e398733ee37366b2da92608085a8ad2 (resized).jpgsys11_08 (resized).jpgsys11_test (resized).jpgwms sys 9-11 (resized).JPG