Fanuc 16i SRAM Parity Error - Faulty SRAM Module? Sanity Check

Hi Folks,

I have a 16i-MA (A20B-8100-0130 Main board, A20B-3300-0050 CPU, B0F4-19) that I am trying to upgrade from 1MB SRAM to 3MB SRAM (A20B-3900-0020). I'm getting an SRAM parity error when I try to clear SRAM using reset+delete on boot or when I try to restore data to it using the bootloader menu. The bootloader correctly recognizes the SRAM module as a 3MB card. I just wanted to make sure there isn't something at the bootloader level or on the mainboard that would prevent initializing the larger SRAM module. The thing that makes me suspicious is the fact that I get the parity error on restore when it hits the 3rd 512KB file to restore, so it would appear that it can write the first 1MB without issue. I've seen the same behavior on two separate 16i controls I have on the bench, so I suspect I might have gotten a faulty SRAM module but I wanted to check here to see if anyone has other suggestions as to something I may be missing.

I know that this combination of mainboard, CPU, Software, and SRAM works correctly, as its the exact same 16i control build that I have in another machine.

The SRAm module is likely defective if you get the parity error when powering up with RESET and DELETE pressed. Another way to clear the meory is in IPL mode (powering up with - and . pressed+ and then entering the CLEAR menu.
You cannot just 'RESTORE' a SRAM backup to a different size.

memoryman. Thanks for the additional tip on IPL. I was testing by trying to restore the 3MB backup from another machine when the RESET+DELETE failed, I should have clarified that. Also, the test controls (yes, I have tried two of them) where I'm seeing the error are in test racks / on the bench, not installed in a machine. Just wanted to clarify so nobody thinks I'm restoring random SRAM data to a machine only to have it go nuts on startup and kill someone, like the transplanted brain in a robocop movie.

No love clearing from the IPL menu either. Bad module it is. Now for the argument with the vendor over the return and replacement. :-/

You CAN restore a SRAM backup from a different size, but it requires a bit more work.
Restoring from a different machine is not recommended.
If you had purchased the module from us, a replacement would be on the way...

Usually when i replace an SRAM PCB,i always reconstruct the structure by loading the CNC and PMC parametrs from NC menu along with macro,offset,work offset ,pitch error,etc
Doing an SRAM restore on a new PCB will end sometimes in altered data
Like Memoryman said,restoring an SRAM from a different with a similar machine must be done if the machine has the same servo motors,spindle motors,options enabled and functions enabled by keeprelays,data table ,timers,counters

Indeed if you have no SRAM to put in,you can try it but always is need it to check all the data like i said above to be sure that machine will work porperly.