Industrial 512kb Flash Card Repair - Page 1
Forum section: electronics / repair

author: Marc M.
author_rank: Regular Contributor
timestamp: September 18, 2025, 08:51:47 am
content: I'm a CNC technician and have a number of machines that are using older Fanuc Power Mate D controllers to run their matrix style tool magazines. Over a shut-down we lost the SRAM contents of one of the controllers due to a failed backup battery. Each of the 6 machines came with a Fujitsu 512kb Flash card that contained a backup of the Power Mate memory that sat in an envelope inside the mag control cabinet. When I tried to restore the controller memory I found that 5 of the 6 cards were bad, the controller won't recognize them. I managed to get the backup done with the single good card I have but I'm worried that it will soon fail like the others. I've been trying to source a replacement card for years but have been unsuccessful. CNC Specialties used to offer them, but can no longer get the chips required so they've discontinued them. They're currently working on a smaller sized card but it's SRAM based and won't work with these older Fanuc controllers. According to the machine tool builder, I must use a 512k card, a 1m or larger won't work, but it's pretty much impossible to find these tiny cards today. It also has to have 'attribute memory' which from what I understand a compact flash card in a PCMCIA adapter won't have therefore they're unusable even if I found a tiny 512k compact flash card.I lifted the skirt on one of the bad cards and found 4x Catalyst CAT28F010T 128K x 8-bit flash chips, a Fujitsu MB623014 controller chip, and an Atmel AT28C16 2K x 8 EEPROM which I think contains the "attribute" data. I suspect that the EEPROM is degrading causing bit rot. Atmel guaranteed data retention for 10 years, with 10-20 years typical. These cards are now 25-26 years old so I think it's plausible. If this is the case then I'm on borrowed time with the one working card I have left. Without the card I can't backup or restore parts of the memory (PMC ladder for instance) which would scrap the machine. Fanuc doesn't have a source for these cards either making the working one I have a bit of a unicorn.If I'm correct and the EEPROMs are rotting, then I should be able to read the EEPROM on the working card then re-write the EEPROMs on the bad cards to resurrect them. I'm very concerned about doing anything that might damage the working card. I don't know if I can read the EEPROM in-circuit as I'm worried that the heat from desoldering the chip might accelerate the deterioration and kill the chip. I thought I'd jump on Dave's forum and ask you much smarter folks for your opinion. Is my basic premise that the EEPROMs are failing correct? What's the safest way I can proceed?Marc --

author: Kwakerman
author_rank: Regular Contributor
timestamp: September 18, 2025, 09:36:04 pm
content: Is it worth contacting a data recovery company? They should have the knowledge and equipment to read the good card and possibly recover / reload the other cards. I know it won't be cheap but on the other hand what would be the price of replacing the machines. Due to the potential risks involved (data loss) this is probably a good reason to call in a specialist rather than having a go yourself and learning by your mistakes (which would be my normal preferred option).

author: wraper
author_rank: Unknown
timestamp: September 18, 2025, 09:53:31 pm
content: No way to read/program these chips without desoldering them.QuoteYou can spend $14 on this onehttps://www.ebay.com/itm/144247417590, might work despite larger capacity.

author: aeg
author_rank: Regular Contributor
timestamp: September 18, 2025, 10:01:28 pm
content: I would probably start by trying to dump the attribute memory from one of the dead cards using a laptop with PCMCIA slot running Linux.https://www.cs.auckland.ac.nz/references/unix/man/memory_cs.4.html

author: m k
author_rank: Super Contributor
timestamp: September 19, 2025, 06:27:26 am
content: Cut power lines for few bad card 28C16 chips and read them without desoldering.Read next if data seems to be partially ok and hope that you can combine a good one.When using other chips you can fake their IDs.

author: wraper
author_rank: Unknown
timestamp: September 19, 2025, 10:16:41 am
content: Quote from: m k on September 19, 2025, 06:27:26 amAs if there are no protection diodes on data pins of ICs they will be powered through. You're suggesting butchering PCBs for something that won't work. Also you'll need to solder to those pins anyway as there are no programming clips of such size. If concerned about heating, one could use low melting point alloy such as ChipQuik alloy or Wood's metal for removing ICs.

author: voltsandjolts
author_rank: Unknown
timestamp: September 19, 2025, 12:35:24 pm
content: So these EEPROM and FLASH EEPROM chips store data, all the 0's and 1's, in 'buckets' that are either filled with electrons or devoid of electons. Each bucket is a tiny floating gate of a transistor, and it will 'leak' some electrons over time, eventually causing data corruption and loss. The EEPROM (AT28C16) will have larger more robust 'buckets' than the FLASH devices, so I would expect the EEPROM data to be kept safe for longer than in the FLASH.The boards look in good physical condition. Yes, they may have lost data bits, but they could still be useable if erased and refreshed with good data again. So the buckets that were 60% full, become 100% full again, so to speak. But some buckets may have large rust holes in them now.Ideally, you would have a copy of the good data on multiple modern day computers and drives, for backup purposes. Then when you needed to transfer it to a CNC machine, you would copy the data to one of these cards. I mean, don't depend of them for long term storage of important data.I think it's important to find a way to read/write these cards from a modern day computer. Note that "ICMC V4.1" is the same as PCMCIA 2.0, so as suggested above, an older laptop with PCMCIA might do the trick. Or a USB to PCMCIA card reader. Test on one of the bad cards first.I have no knowledge of the data format used by your CNC machines, it might be something windows compatible like FAT16 or such. If it's a custom format, you would need specialised software running on your computer to read/wite the cards.CNC forums might have more info, such as:https://www.practicalmachinist.com/forum/threads/need-advise-on-cf-card.289052/What does a "Fanuc Power Mate D" look like? Answer:https://www.dnc-electronics.co.uk/parts/fanuc-system/powermate/a02b-0166-b531/Google tells me it uses FAT16 format on the CF cards.Possible solution:https://www.cnc.uk.com/fanuc-flash-kit/Which just looks like a standard Compact Flash card plus a holder/adapter for the Fanuc PCMCIA slot.https://www.google.com/search?q=compact+flash+to+pcmcia+adapterAnd that smaller style of CF card 512KB are readily available used on ebay...in fact prices are quite high. I need to dig out my old CF cards.

author: m k
author_rank: Super Contributor
timestamp: September 19, 2025, 08:12:17 pm
content: So the ROM is a byte write, static RAM style chip and its specific data is not needed.Only functional and accepted card is needed.Old card seems to have a single point power, from left of C5 to the chip, easy to fix afterwards also if cut.Cut that of a new card and write the attribute chip using external power to act as a 512kB thing.There can be some Fanuc specific stuff, you must maintain that also.Fujitsu controller is a bit less common, can't find what it actually is.

author: amyk
author_rank: Super Contributor
timestamp: September 20, 2025, 03:39:02 am
content: The AT28C16 (not the E-variant which has 10x higher endurance, and surprisingly they didn't even use the industrial extended-temperature version) is rated for 10k cycles while the CAT28F010T is rated for 100k cycles. I believe the retention specs for this low-density SLC flash is for after the rated number of cycles have been reached and at maximum temperature, i.e. 10 years after 10k cycles and stored at 70C, so unless they were heavily written to, I suspect your cards may have failed by other means (ESD?) than charge leakage.As for making a replacement card, a CPLD with a few parallel FRAMs seems suitable. The interface is very similar to the old ISA bus.

author: Kean
author_rank: Unknown
timestamp: September 20, 2025, 11:04:02 am
content: I would go searching for some old PCMCIA or Compact Flash cards and see if they are recognised.There is this option but they are rather expensive, and may not work in your application but they seem to offer a money back guarantee.Not really that expensive for a business maintaining old machines which would be far more expensive to replace.https://cnc-specialty-store.com/flash-sram-cards/sram-card-512kb-with-8k-attribute