Fanuc error 998 ROM Parity Error ???

[ED209]

Just bought a used 1990 Leadwell LTC-20CP lathe with a Fanuc OT control. Just powered up & get error 998 ROM PARITY ERROR, ROM NO 0E1, 0665-13

What is this & how to fix it ?, the manual lists the error but no remark on what to do.

Thanks

ps. I don't know squat about the electronics side of cnc machines

[valmet58]

The rom chip contains the codes that the computer runs..if it is bad it needs to be replaced...the first thing you should check is your 5 Volts power supply..
It needs to be at least 5.2 Volts..if it is too low you can get all kinds of bad messages like the one you have..hope this helps

[ED209]

Hi Andy thanks for the reply. I am lacking experiance with the electronics side of cnc machines. How do I check the 5v power supply ?, is this the back up battery ?

[ED209]

ok a bit more info on this machine.

main board A20B-2000-0170/02A
MEMORY BOARD A16B-1212-021 with a small square & then a rectangle ?? could be a A16B-1212-0210 ???
series OTF
software version 0665-13

I found a couple pics on the net of the boards I think, can't get to machine right now cause it's about 100km away & snow storm coming through. Friend out there did go & have a look at it & gave me #'s off the boards.

I read on one thread that it's possible the ROM chip(s) or board could be loose ? this machine has travelled a fair distance from original owner to machine tool sales company then to our location.

The back up batteries were replaced with no luck, 3 D size batteries.

Valmet58, Andy mentioned the 5 volt power supply. Would someone please explain what he means by this & how to check it.

Also is the ROM chips located on the memory board & if so how do I know which one it is ? The alarm states ROM No. 01E or O1E how do I know which one it is ?

Any help on this would be great

[ker2008]

PMC EPROM CHIP ： 0E1 、 0E2

[ED209]

Thanks ker2008 for the reply. Now is that on the memory board, main board, else where ? & how do I find it ?

[ker2008]

the 0E1 0E2 is 27C256（PMC-L） ， memory board .

QQ??--????

[humak16]

ED209: Try ,erase memory and then reload all PMC and NC parameters, also Macro programms(9000 and 8000). Make a back-up before erasing memory.

[ED209]

Thanks for the replies. Can't back up the parameters because you can't get past the alarm screen it comes up as soon as control powers up. I sent an email to the previous owner & hope they have a back up of the parameters. I do have hard copies in the electrical manual of the parameters but not sure if it's all there or how up to date they are. This machine was upgraded to a larger chuck 12" & thru spindle bore.

Parameter list in electrical manual
1 - 759
900 - 919
1000 - 2059
8100 - 826
D300 - D491

Macro progs ? I have a hard copy of O9001 to O9004 but no idea what they are for. See attached files.

So how do I erase the memory and reload it then ?
I found something about clearing memory on the Intelligent search technology and Information management solutions| Memex site please see attached file. Is this what you mean by erasing the memory ?.

Thanks

[ED209]

sorry wrong link to memex, try this Manuals

[humak16]

Yes, Power up the machine pressing "Reset + Delete". This will erase all the parameters and programs. It is useless to do this if you don't have a back up copy. You must have a copy of parameters (NC + PC) on some paper, not in the manual. Parameters are very specific to the machine. You can contact MTB as they normally keep a copy with them. You should also have special parameters (900 ~940).

[ED209]

ok thanks humak16. We are going to check for loose boards or chips first. Then will try dumping the memory & reload parameters. I emailed the previous owner & they do not have back up copies of the parameters but he did say they lost them once & they used the ones from the electrical manual. There are penciled in changes in the parameter so I'm guessing they should be good.