[david_chen]

Hi all,
My milling machine with Fanuc 6M has an error displays on CRT when I power on:
SYSTEM ERROR 998
101 5D
and the control hangs ...
Refers to the Fanuc manual,this error causes by parity error of rom 101 but I don't know the meaning of "5D" and how the controller can check the roms parity?
Can anyone explain me the meaning of "5D" in the error message and the way that the controller check the rom parity
Any help will appreciated
Thanks
David

[memoryman]

Every rom has a calculated checksum that is part of the rom data, similar to parity checking.
The 5D is that checksum value. It has no use for you; a system rom in location 101 has to be replaced.
What is your software version?

[david_chen]

Every rom has a calculated checksum that is part of the rom data, similar to parity checking.
The 5D is that checksum value. It has no use for you; a system rom in location 101 has to be replaced.
What is your software version?

Thanks for your reply,memoryman
The software series 907 version 10.
One more question :If the 5D is the checksum ,can we use it to locate the error address?where is the position of the checksum in the rom map?

[memoryman]

We don't have a copy of that.
No, the checksum does not identify what the error is or where it is in the rom.

[david_chen]

We don't have a copy of that.
No, the checksum does not identify what the error is or where it is in the rom.

Thank you memoryman
David

[jaredvj]

We don't have a copy of that.
No, the checksum does not identify what the error is or where it is in the rom.

Hi, do you have a way to solve Fanuc 6m Model b, error 998: 151 00, 152 00?

[memoryman]

Either there is a bad system software eprom on the ROM board (location 151 or 152) or you Bubble Memory (BMU) is corrupted (in which case you have lost all data). If that is the case, you will have to re-initialise the BMU per the instructions in the maintenance manual. If that is successful, restore parameters etc.

[jaredvj]

Either there is a bad system software eprom on the ROM board (location 151 or 152) or you Bubble Memory (BMU) is corrupted (in which case you have lost all data). If that is the case, you will have to re-initialise the BMU per the instructions in the maintenance manual. If that is successful, restore parameters etc.

Thanks for your reply!
Which means I have to try hard reset by press and hold -/+ & . on the keyboard?

But I had this message before the system error 998 appear.
Msg as attached picture

[memoryman]

That message will re-appear, as the system software version is stored as the system label on the bubble memory board (BMU), and pressing and holding - & . on the keyboard clears that info, along with all other data on the BMU.