Occasional CRC Errors- 1993 VF3

About every 3rd or 4th time I turn on my HAAS I get an Offset CRC error, which is usually the G52 X value going to some ludicrous number. Easy fix, whatever. Nothing else changes.

Once in a blue moon I will get a setting CRC error or a program CRC error though, and those are somewhat more inconvenient to reload (though I just push things back via serial and all is well).

The batteries are fine- I have two attached on the offical haas dual battery PCB and recently changed them to see if they were the issue. I've checked for loose connections throughout the board stack, but nothing obvious shows up. Do I just have a failing chip somewhere and I'm sitting on a ticking time bomb or is it likely fine as long as it doesn't degrade further?

Don't you love when you search google and find your own thread almost 2 years later?

Still having this issue, with more frequency. I've just got a parameter, offset, and setting backup ready to send over serial if needed. Machine usually forgets something every few boots. It's tempting to pull the boards and start looking up part numbers, maybe I can repair this. Seems like a bad memory chip. If anyone has any info on that let me know, no point in reinventing the wheel if someone already knows how to do it.

npolanosky said:

Don't you love when you search google and find your own thread almost 2 years later?

Still having this issue, with more frequency.

Click to expand...

Usually CRC is a "cyclic redundancy check" and refers to a hard drive error. Does this control have a hard disk ? If so, you may want to replace it .... various file systems will re-write bad sectors to good sectors so the impending failure is not obvious, but when you run out of good sectors to write to, you're up poopoo creek. Plus the crc errors are a pita, but you already knew that.

Whats a CRC function? First paragraph has a good summary
Cyclic redundancy check - Wikipedia

How Haas used this for a 93 OS I really do not know. But, from a 'givins' standpoint: -There is a data check being performed - There is data change being observed, so it's working. I used to do a lot of this type of board repair stuff and it's hard to isolate. a sticky bit in a latch... a memory cell getting inverted.. I mean it's not easy to do w/o knowing the exact detail of where the data is stored, what memory address is being interrogated etc. Anyway- It's doable but usually by a 'shotgun' method which is hard on these SMT boards. Just some thoughts on it anyway- Now, from some recent experience and searching this forum for CRC errors, there are two key things we found; A- LV power supply acting up. Have you replace the supply ever? That's an old machine... And then to dump and reload the programs. maybe on this it's dump and reload the offsets? Anyway- We replaced our LV power supply recently and alsoi reloaded our programs (9k's included) and have not seen it in over a month now. But we do not run a lot of late. Some thoughts on a Sat morning over coffee.

CRC is not just for hard disks, it is for finding errors in any data transmission.
On-line CRC calculation and free library - Lammert Bies

I just sold a vf2 about that age that poped up with an ofset crc error every morning for 8-10 years, I never could tell what was causing it but it didn't cause any problems, reset cleared it then it ran just fine.