SAVP 3-Reel Shelf board problem/question

[VPTech65]

We have an SAVP that has a P/N 76942000W reel driver board that went bad.  I ordered a replacement from IGT and all they have is a refurbished reel shelf assembly with a P/N 76943500W board and we can't get it to work.  The IGT service tech tried flashing it with several different firmware versions. We tried both the bios chip that came with it and the one from the original board, verified dip switch settings, and did everything else we can think of.  We swapped it between machines and the problem definitely follows the board and the original problem machine works with the board from the good machine.  What the replacement board does is goes into a reel tilt on all 3 reels immediately, and goes right back into it as soon as we try to reset it.  So mainly I'm wondering if anyone knows for sure if a 79643500W board will work to replace a 79642000W, and if yes, what needs to be done to make it work? 
Thanks in advance for your help!

[shortrackskater]

Subject moved from GENERAL CHAT to IGT S-AVP
~moderator

[VPTech65]

I had temporarily gotten my original board working but now it died again.  It won't communicate USB at all, not seen by my PC or the driver update utility and Red LED DS8 is on solid.  So I'm back in the same boat.  IGT sold me a refurbished reel shelf with a 76943500W board and they insist it's a valid compatible replacement but I can't get it to work.  This makes a total of 6 of them I've tried, and with various flash firmware versions from BFRD0006 to BFRD0030 and everything in-between.  I've also confirmed that the game works with the good board from the game next to it and the new board has the same tilt in the good machine.  So I'm hoping to find someone else who has also tried replacing a 76942000W with a 76943500W and can confirm weather or not it worked.  And what had to be done to make it work if any success was had. (Ram clear, option change, new reel assemblies, etc.)  Also if anyone knows where I might find an original 76942000W please let me know.  Thanks again

[VPTech65]

Still trying to fix my 76942000W reel shelf board because I can't find a replacement.  After further research, I figured out why the new type of board, the 76943500W doesn't work in the game.  It is actually compatible with the game but not the current reels.  The old machines like mine only have a single white reel backlight but the new ones have the RGB light boards.  It's looking for those and doesn't see them so it goes into a tilt.  If I were tp purchase 3 new PN 66040101R Reel Assemblies (Wide, BP, JPO, RGB) then I could use the new board which I have several of on hand.  But unfortunately for reasons I don't want to get into here, I currently can't buy anything from IGT.  So I was wondering if anyone has schematics of the 76942000W reel shelf board?  On a very similar board 76941900W (4 reel type) I'm using for comparison troubleshooting, I see the chip select pin 1 of the boot chip toggles a few times on powerup and stays high, but on my dead board it stays low.  And I trace it all the way back to the big Xilinx Spartan IC. I can't go much further without a schematic.  If anyone has any documentation they'd be willing to share, or has seen this before and knows the solution, please let me know.  (And I did verify all the power supply voltages are present and good btw)
Thanks

[VPTech65]

I found out the compatibility issue is the old boards like my P/N 76942000W are only for a single white light reel backlight but the new ones like 76943500W are for reels with RGB backlights.  IGT told me if I replaced all 3 reel assemblies with the new type it would work.  Fortunately I was able to get an original 76942000W board from an aftermarket vendor and the game is finally up and running now.  Those old green boards are pretty much non-existent and I was very lucky to find one.