Display Netplex Link is Down With Enhanced R Board

[coorslight115]

I have read thru all the items we have listed on the "Display Netplex Link is Down" . Most pertain to the 960 boards. I have a machine I picked up that has an enhanced board and is a R board game. The machine is a Double Dollar 3x4x5x 5 reel 120 credit machine. It has WBA13, Gen2 and LED reels. When powering up you get the message "Displays Netplex Link is Down" and it blinks on and off. The leds on the MPU also blink . If you let the machine sit for a half hour or so on, and turn it on and off it may boot and play normally. One time it booted and gave me the "Call Attendant" message and gave a Ram Error. I cleared by turning key and got a Primary SAS down error. The machine was playing a few minutes earlier??? I used a RBK clear and reset the ram, eeprom and keychip settings and played the machine for over an hour with everything working just fine, including printer and validator. Turned it off for 30 minutes and it will not boot and have the original "Displays Netplex Link is Down" again.

I have tried:
Swapped MPU with known good ones and this one works in other machines
unplugged all netplex devices and swapped them with known good ones
Green battery is 3.1 volts
Coin battery is new and proper voltage
all three I/o cards swapped with good machine\
no bent pins on MPU or R board card
swapped power supply behind reels with known good one
swapped printer, WBA, credit displays and backlit controller

part that has me confused is that the machine played ...then came up with ram error and primary sas down with no changes other than power down. Battery not the issue...done same thing with other MPU's that work fine in other machines. Unless this is an R board issue. I only have the one R piggy back board.
Lost on this one....unless it is a connection issue somewhere. And yes I have unplugged every netplex connection in the machine and have the same error

Again...The machine will occasionally boot and play just fine...That is the confusing part...

[cowboygames]

Can you try a different theme either with a legacy adapter and SB, SG chips or a different theme R board to narrow it down some more?

[FORDSBS]

Wish I could help but don't know what to tell you.

[rickhunter]

I would put my money on the R-board.  Do what cowboy says, try a legacy game and let it run for a while to see if it crashes on you, if it doesn't, you have isolated your issue.  Sucks if it's the R-board, I know how hard these are to come by.

[vtyler]

was the know good power supply the proper amperage. s2000s and i games have 2 different amp power supply's and some games will not run on the lower amp psu. i have seen similar problems when running too low amp of a psu in a machine.

[coorslight115]

was the know good power supply the proper amperage. s2000s and i games have 2 different amp power supply's and some games will not run on the lower amp psu. i have seen similar problems when running too low amp of a psu in a machine.

Was correct power supply out of same type of game. Not a WinTach supply

[vtyler]

same type and config game(r board number of reels and bonus devices). we had a big times pay at my work the power supply failed we swapped in a low amp psu that we knew was good started giving very similar problems. we spent hours trying to find out what the problem was before we noticed the old psu was rated for higher amps.