Need Help!- EEROM malfunction

[Tom Newsome]

I have a GCC mercury which I bought new from the Australian supplier in 2000 and basically I have had to look after all my own problems. I am electronics minded which helps, but have very little info on the machine. It has developed the following fault.
During Power On Self Test, it comes up with the error "EEROM Malfunction Replace EEROM"
Also it does not sound the EOF alarm now, nor does it lower the table before setting the head to Home position. This can be a problem when using the rotary attachment. However the machine still accepts files and still cuts. It also allows me to lower and raise the table from the panel. (If I need to put the Rotary attachment on I have to power up the machine, Lower the table, Switch off, Fit attachment and re-power the machine.)
The other problem I have had is that the engraving level has been too high. Files that I have used many times over, now engrave deep and even through the 4mm plywood when doing (vector) text, but are skinny on the vector lines when the speed picks up. the penetration into acrylic was really bad and I had to turn the power down to 1% for engraving vector part of text (raster part seems OK)

If I try to change any parameters using the front panel it sometimes appears to change them even though it reports a EEROM error during the process.
On Power up it reports "Laserpro MERCURY", "Firmware V2.17-07", "Copyright 2002".
Then I get the EEROM error message.
"EEROM Malfunction Replace EEROM"

Is anyone able to tell me which chip the EEROM is? I am hoping it is one of the socket ones, but as some have labels over the chips I have not gone so far as to remove those that obscure the chip type. Of course this might be my next course of action, but I thought that running it past the forum might give me better information on this problem before I risk the soldering iron !
Hope you can either help me, point me in the direction of help,

Kindest regards

Tom Newsome
Northam
Western Australia

[Horsedorf]

Can you upload a good resolution photo of the circuit board with the chips on it?
also, it depends on what's in the EEROM as to whether or not it is replaceable. Ie, if it holds code , then you might be out of luck.

[Tom Newsome]

Hi Horsedorf,
Not too sure about upload limits or even how to upload pictures to the right spot, so I put it up on a spare web page I have and here is the link
Temporary site for Laser Mainboard Photo
It is detailed enough to read the chips and hopefully not too slow for you to download.
Thanks for your interest.
Kindest regards

Tom Newsome

[Zig]

Hello Tom,

My commiserations.

There are two eprom chips on that circuit board. They are socketed in the ODD and EVEN labeled sockets.

They appear to contain the operating firmware. It may be that all You need do is prize the chip out ofits socket carefully and re insert making sure no pins get bent in the process.
Sometimes after a while the pins and the sockets tend to corrode resulting in poor contact.

If you are fortunate enough to have a contact problem the machine should come back to life once the chips are reseated.

If that is the case great. Otherwise You will have to put up with limitations of the dud chip.

If it comes good and the original supplier of electronics has gone tits up, peel the labels off the chips, identify part number and see if there is anyone who can burn You a spare set of chips for those '...ohh bugger.. " times.

If the firmware has lost integrity You may be able to flip a few bits depending on word parity and error checking and correction of eprom burner in the hope of dtumbling upon the happy combination again.

Greetings from Brissy


PS.. You can always replace the old controller with EMC2 solution.

[rgammage]

Hello Tom

I think you will find these devices are more often called E(squared)ROMs. Please can you find the device number on U38, U55 and U54, as these would seem to be favourite?

Regards

Richard

[OldEngraver]

I have the same machine as yours and I always power off to fit the rotary attachment. When I purchased it, the seller said that the rotary attachment cable should never be plugged in while the machine was turned on.
Good luck with your problem!

[Horsedorf]

The CA82C54 are programmable interval timers.

Looks like you are using a 68020 so you likely have pairs of roms for most things, like, u8 and u9 will likely be the firmware as it is paired as even and odd and has versioning information written on it, there are several other devices there that are socketed, EPLD's, they are gate programmable logic devices, most likely. They *MIGHT* conceivably be harboring some eerom in them that has been made accessible, so as the other poster suggested, just lifting them from the socket and then reseating them might help.

U10-13 are static ram devices.

Unfortunately, I can not read the tops of those devices you want identified *AT ALL* there image is just not there, if you can get a better picture of them I can look up those parts for you.

Zig already identified U8 and U9 Correctly. I've worked on a LOT of 020 systems myself. The parts you are pointing out, u38,55 and 54 are most likely single gate logic devices used to generate an address strobe or a select for various parts they are close to. The motorolla 68020 system typically had a lot of discrete logic laying around the board for addressing things. Thought they *MIGHT* be I2C or SPI memory devices.

Boy, I sure hope they were not using your firmware eerom as a place to save system run time information.. those have limited write cycles, like.. 100k or so, USED to be only about 10k cycles, during the era that that board was likely made, late 90's.

[Tom Newsome]

Hi guys
Thanks for all your help. It looks like Richard got it right, - U38 is an Atmel 93C46 which is a 1k serial eeprom. have looked on the net for one and they are cheap enough, but I have to make sure I get the right package type for the board.
When I have changed it I'll let you know how I went. I have also come across someone who may have a spare main board from a ratted machine, but it depends how much he wants I suppose. It will probably be as easy to get the chip as the board, I'll check.
I feel somewhat relieved now. so I will keep you posted.
Oh, I did reseat the chips earlier to no avail, and re-flashed the firmware. That's what puzzled me the most- and as Horsedorf said they surely would not put the variables in the firmware chips,....... so I am now on the right lines with U38 and I'll let you know how it goes. watch this space !
By the way, Oldengraver, I always plug/unplug rotary attachment when the machine is off. That's the point. I have to power up to lower it from the panel before I can switch off to plug in the attachment.

The main reason that all this is such a pain is that I made up a circuit using a mic and tone detector tuned the EOF beeper to trigger cutting the airjet and suction fans when the job was finished. The beeper is such a feeble device and this box I knocked up also sounds a local and remote alarm. So I put the next work piece in at the adverts if we are watching the telly ! With this eeprom malfunction the beeper doesn't sound any more and I have to keep checking the job and the fans/airjet stay on all the time !
Kindest regards to all

Tom Newsome

[Horsedorf]

http://www.atmel.com/dyn/resources/p...ts/doc5193.pdf

starting at page 15 of this document I have linked, are all the package types and the measurements for them. YOu can determine the package type pretty easily this way.

It looks to me like an SOIC, you can get them at digikey. They are all 5.5 volt tolerant, so any should to fine as long as it has the right footprint. There are no goofy memory organization differences between types of this part either, so you should be fine with whichever one you get.

Heck, you MIGHT even be able to just to go atmel's web site and get a few samples for free.. I'd try with that, first.....

Rick

[Tom Newsome]

Hi Folks
Great news. My little beauty 73 cent soic chip (U38) arrived today and I soldered it in place and hey presto all those faults have gone. My beeper has returned and the engraving level is correct again, no more error warning messages, and the z axis operates on POST.
So all I can say guys is thanks for your help and I guess that is the end of this thread isn't it.
Cheers!
kindest regards

Tom Newsome

[Horsedorf]

DUDE! Congrats!
I will admit a bit of skepticism.. okay, a LOT of skepticism at that being the only thing wrong, but, dang, that's awesome that that fixed it. NOw you have a spare board!

[Tweakie]

Great news indeed Tom

Tweakie.