Fanuc 10T system label error

[Andy Fritz]

Hi Guys,

Every now and then the control throws up a garbled screen or the one in the picture below.

It always happen while the machine and control is under power.
Usually I just reboot and everything is fine. On three occasions it did not work to just reboot and then I get the below system label check; ERROR.

After this I go through the zap memory, input options, restore parameters etc. and that works fine. I would now like to find out what needs replacement to stop this from happening. The control does not have bubble memory and I doubt it has anything to do with the back up batteries as they test fine and as the problem occurs while the machine is powered up. The IPL screen says; END after checking ROM and RAM. Assuming that means OK I guess the memory module is OK. So what should I repair or replace?

All the best,

Andy

[fordav11]

I found a small reference to the Label Check Error in the 21i Maintenance manual (I don't have 10-series maintenance manual).
See attached.

It suggests clearing SRAM by holding reset+delete then reloading the system software. That probably means parameters, PMC data etc.

I don't know what 'system software' means exactly but it looks like your machine does not like something in the memory.
It could be parameters/PMC related or it could be the boot software?
You say the Memory is ok but the Memory Module and the SRAM Module are not the same thing. They are two different pieces of hardware. The memory check is the DIMM module.
Maybe your SRAM module is faulty and you need to replace it?

[Andy Fritz]

By the sound of it, I think what you are describing is the equivalent to what I am doing to recover the machine each time the system fails. It works fine, but the best solution would be to find out why the problem occurs in the first place and then replace the bad component.

Andy

[fordav11]

I would start by replacing the SRAM Module.

[Andy Fritz]

Do you mean the 6 pcs RAM chips on the right hand bottom corner of the mother board or the AD memory card?

Andy

I would start by replacing the SRAM Module.

[fordav11]

I would think it'd be a plug-in card of some kind but I don't know the 10-series hardware. I don't have a definitive answer.
If you post a pic of hardware circuit boards I may be able to see.
The info should be in any Fanuc 10-series maintenance manual. Unfortunately they are not available in pdf form.

[Andy Fritz]

I have the maintenance manual. It says there are 6 SRAM ICs on the mother board, but I count 8 pcs. Two are HM6264P-15 and six are HM6264LP-15. All 8 units are 64K each.

Then there is a plug in type card for additional ROM and RAM called A16B-1210-0381.

Andy

I would think it'd be a plug-in card of some kind but I don't know the 10-series hardware. I don't have a definitive answer.
If you post a pic of hardware circuit boards I may be able to see.
The info should be in any Fanuc 10-series maintenance manual. Unfortunately they are not available in pdf form.

[fordav11]

ok the eight 6264 chips are common 8k x8 bit Static RAM chips. You can get them on ebay for a few cents each. Common as dirt.
As long as they are socketed you can swap them easily yourself. If they are soldered into the PCB you will need someone with the required knowledge and equipment to remove and replace them.

I Googled the A16B-1210-0381 board
I assume it's this one....
http://cdn3.iofferphoto.com/img3/ite...8/070/1TME.jpg

What RAM chips are on there? From the size of them they look like the same type 6264 (i.e. 8k SRAM) , but only two there so a total of 16kb.

RAM chips are the ones with a number then a dash then a smaller number
Like HM6264LP-15. The 15 means the speed in nano-seconds and usually it needs to be multiplied by 10. a -15 means 150 nano seconds. The speed of the RAM is quite important if you are going to replace it get the same speed or faster (faster would be -12 or -10 or -9 or -8).

also if this is the main board I see the 64k SRAM lower right corner. There might be more RAM chips on it. Possibly smaller physical size? Check it closely.
http://www.cnc-shopping.co.uk/images/A16B-1010-0040.jpg

however I suspect your problem might be with the SRAM on your A16B-1210-0381 board....

[Andy Fritz]

Thanks for the help,

I ordered 10 pcs of the cheap 16k IC's from ebay just in case.
Is there an easy way to determine if an IC is RAM, ROM or something else?
The mother board is packed with IC's and unless I know what to look for it would be difficult.

The Ad memory board has two of the same 16K IC's as the two from the mother boards eight SRAMs, HM6264P-15, and there are also two others of same size but made by Intel. They seem to be matched as both has a sticker with the number 1220. I had a look on ebay for boards with same model and revision number and they also had stickers on the Intel IC's with matched numbers, but not same as mine. On the intel IC's the print says;
D27256-25 on the top row (same number of both). Second row is different between the pair so maybe a manufacturing batch and serial.
Third row is same on both and reads PGM (a) 12.5V

Some of these boards has 4 pcs of the intel IC's and there are space for 8 pcs so I believe the intel IC are the ones which stores part programs, offsets etc and the number of intel pairs represent how many meters of equivalent tape memory you have.

I can buy another board to see but as this problem only occurs maybe every 2 - 3 months it might take half a year to find out which, if any, of the SRAMs is bad.

As it looks like the control runs a memory test in IPL mode and does not flag ROM or RAM as bad I am wondering if the problem might be elsewhere.
It is always the System label check that fails. What is the system label and does the system not sit burned in on a dedicated chip? If it does and it is damaged how can the system label be rebuilt by resetting the memory?

Andy

Andy

[fordav11]

the 27256 are common 32k EPROMs. They are probably ok. if not you must buy new chips already programmed or another board because you have no backup of the data inside them.

The start-up ROM/RAM test only tests main RAM and boot ROM not anything else.

If you send me a high quality pic of the board I will tell you what every chip does right down to the bit-level ;-)

With the right equipment you could test each RAM chip. Even so it's a specialized repair job requiring technical electronic knowledge. The best you can do is swap the RAM with known good chips or replace the entire PCB.

[Andy Fritz]

Thanks! Very good info.

If the control does not test the total memory on start up it would explain a lot and like you say swapping out cheap SRAM is the best approach. The Ad memory board is only a few 100 USD but I would prefer to chase up every thinkable SRAM chip on the mother board as the MB would cost 2 - 3 K USD to replace. As the manual shows 6 SRAM chips, but there are 8, there might be others with different foot print. If you could help me spot any additional SRAM on the MB from a high res picture that would be great help. I cant upload that here. Maybe you could PM me your email?

Thanks,

Andy

[fordav11]

I guess the SRAM on the motherboard is used as main RAM and work RAM (i.e. some semi-permanent storage while power is on for it's program data plus an area that changes continually). It is connected directly to the CPU so it can be tested because on power-up it contains nothing. To test RAM requires it to be written and read back then compared. If the contents match then the RAM is ok. The additional RAM can not be fully tested because it contains your data, offsets, parameters etc. Writing to it will destroy the data. My best guess is a CRC is created when the power is switched off and on power-on it checks to see if the CRC is the same. If not you get that alarm because it thinks the SRAM has been corrupted somehow. The common parity alarm probably comes from a similar failed CRC check. Also testing every chip on the board takes a lot of time so only the bare minimum is tested in general. Newer PC-based systems are faster and more hardware is tested. I don't know what CPU the 10-series has but it's probably not very fast or powerful.
6-series used Intel 8086 at 8 or 10 MHz. 15 series used 25MHz 68030 typically used in Macs and Amigas in late 80's/early 90's. 16-series uses 486 CPU. 21-series uses Pentium 233 MMX. The CPU gets faster as technology advances but the CPU alone is not a very powerful device in a very complex system like a CNC controller so testing components is kept to a minimum.

The AD RAM board probably contains the ladder (in those EPROMs) and the SRAM there is for part program storage, parameters and other volatile data. I'm just guessing though. Probably 'gbowne1' could give you more info about 10-series hardware.

btw the EPROMs are not re-writable in-circuit. They are Electrically Programmable Read Only Memory (hence EPROM) and require an EPROM programmer to program/re-program them after being erased by exposure to UV light. The sticker on them is probably the ladder software revision or the software version/revision of something. You may be able to check that in the control in the system menu / PMC screen if there is board ID hardware & software revision info listed there..... my 21i has lots of that info

That technology is very old compared to current CNC systems. Now we have flash ROM and flash cards etc but back then the only way to permanently store small amounts of data was in an EPROM or in RAM with a battery backup (or hard drive etc but that is not relevant here)
Your best bet is to change the 6264 SRAMs and see what happens.
I'll PM you as well.