Need Help!- Fanuc 3M-model C

[vavco]

Hello everyone, could anybody give me any advice how to solve the problem of a grinding machine with Fanuc 3M-C (main board A16B-1000-0010).After powering the machine up , switching NC on , alarm "RAM parity high" is displayed
on the screen . Is it a hardware or software problem? I could tell more what I found out during checking the electric parts of the machine. Could anybody tell me more about this main board and jumpers on the board marked LOAD and ROM PARITY? What is a task of battery that supply RAM memories? - to store data for a main program of microprocessor? to store data for machine's parameters , data for programs and subprograms? Thank you. Vlado of Slovakia

[f-bu]

Vlado,
About the battery - yes, all of them - parameters, programs, offsets etc. And the alarm usually says just that - no battery!
Put new batteries, hold RESET and DELETE buttons down and switch on the control. This will clear the RAM memory and the check sum will be correct. After that enter all the parameters, diagnostic data and programs from your backup. If you do not have it - look for similar machine to take one. The a.m. alarm is hardware generated and there is nearly no way to recover missed data.
Nearly - because if there is still a battery connected and the alarm came from some noise, the data, a bit corrupted, could be in. But you need co called "engineering panel" to proceed. I am not sure if in your local Fanuc service there is such a device and old enough engineers, that can "drive" it.

Do not play with LOAD and ROM Parity check points. LOAD, if tied to ground, will wait for a diagnostic programs to be uploaded trough serial port.
ROM PARITY, if tied to ground, will skip ROM parity check. If you are VERY familiar with fanuc software written in the ROMs, you made a great new feature, found free space and put it in, but you are lazy enough and do not want to calculate the new check sums, this jumper is for that.

[vavco]

Thanks a lot , f-bu . To explain more: I was called to have a look at this machine,
because I do running my own business (fixing all kinds of electronic) .So , I can
say, I'm not the beginner , but as to this Fanuc , so far I have not got any experiences
with it. Old grinding machine (1985 ?) with this Fanuc has not been working for a longer
time due a mistake which was made by one man. He accidentally made a short circuit
some where between contacts of relays in a box of machine . This caused destroying
a couple of SN 75463 that drive from connector M2 (outputs) relays and some LED's.
The main board stayed for long time without supply from battery.
Everything was lost from RAM's . Now, I 'm going to fix this problem , so I took the board
to my desk to find out everything that I can, and I started to collect another information
that could help me to solve this problem. As I wrote, on the screen : there is only alarm:
memory parity high . There is another grinding machine (the same model, same system)
that could be helpful for me. I can read EPROM's, verify them , I can rewrite them if
necessary. As to RAM data, I found out there is some software Telix/Procom+/Hyperteminal
that I could use for downloading parameters , etc from working machine and to upload
via RS232 to broken ( fixed) machine. But, probably , it will be a hard way to achieve this
software. I will see. Anyway, I will do what you recommended me , And yes, when alarm memory parity high appeared , battery was plugged in, so it seems it is going to be a bigger problem, if I understood your sentences well. So , if you have anything more to help me,
I will appreciate your help. Take care. Vlado

[f-bu]

Hi Vlado,
Replace 75463, hope the high voltage stopped there. Check the bypass capacitors also. If 220V came to the board trough the outputs, electrolitic caps on +5V are blown, also check 74259( ?? maybe, can not remember, the chips driving the 463's.
If the board was a long time without battery, there is of course nothing in the RAM, so copy parameters from 0 till 99 and from 996 till 1050 or where they ends, can not remember last parameter number. Also, push DGNOS and copy all the data between No, 160 and 223 - these are keep relays, data table(s) and timers. If here are some programs from machine manufacturer, they must have numbers >9000. Sometimes, especially if there is a "program select" rotary switch on the panel, a 0 till 31 numbers could be necessary.
There is not so big number of parameters on 3MC, you can copy/enter them in 15 minutes by hand, so no software is necessary. Well, if there are many programs to enter, it can be done with any terminal program with file transfer ability and XON/XOFF control handshaking. FFanuc format is Even parity, 7 data bits, 1 or 2 stop bits depend on parameters.
My suggestion is first fic hardware, enter parameters, ON/OFF, diagnostic data, and after releasing emergency stop button, if the repair was successful, the control should have no alarms. Try moving the machine, go to reference points. After that you can continue with programs.

[vavco]

Hi f-bu, by the way, it is strange for me to call you f-bu.However, your advices
told me that you know what are you writing about. Yes , you are right. 75463 were
replaced, according to my research , it was likely a short circuit between +24V
and AC 100V . ( relays are supplied by +24V , their contacts use AC 100V to
supply other relays) . So AC100V came into 75463. I suppose , opened collectors
of 75463 saved others logic parts , but it could be some problem with some registers
(as you mentioned) driving 463's . In my case, mostly 74LS374 and one chip 74LS174 .
Or anything else hanging on +24V . I do not see any problem in +5V supplied chips.
(but , I'm not sure). There is also 7812 supplied by +24V , I have to check what circuits
are fed by +12V . It is close to CRT connector , video signal, H and V synchro are ok,
monitor works ok.
I will solve 74LS374 if I come to any state of the system without an alarm.( If they are not
important for turning some special relay on. )
What I do not understand ( from your message) is : Could I copy
any parameters from a broken machine ( with a.m alarm) ? I just spent 2-3
hours with broken machine, so I did not try anything ( I could not because I had
not any knowledge and experiences) . You wrote me , no extra software is necessary.
If I connect a cable from a computer to RS232 , should I know a special way ( pushing
a correct buttons in an order) to load anything from machine ? I have to reread all
what you have written to me, because there is a mish mash in my head. :-)

you wrote :
"My suggestion is first fic hardware, enter parameters, ON/OFF, diagnostic data, and after releasing emergency stop button, if the repair was successful, the control should have no alarms.

My questions are: if I fix hardware( I do not suppose the screen is going to be
without alarm after that) 1. could I enter parameters?
2. what does it mean ON/OFF ?
3. what does it mean diagnostic data?
4. When I should release emergency button?
Maybe it seems that my questions are stupid, but I do not understand almost everything
from this method of going step by step.
Probably I have to go and see the machine and try to make anything
of your advices to see what will happen , where is the access to do something... or
I do not know what else. Then I could be wiser ... at the moment , I know more , thanks
to you , but it is a little bit scrambled in my brain. :-)
Vlado

[f-bu]

Vlado, You said there is same machine, in working condition. I mean copy from there the parameters/diagnostic and enter in yours.

What I do not understand ( from your message) is : Could I copy
any parameters from a broken machine ( with a.m alarm) ? I just spent 2-3
hours with broken machine, so I did not try anything ( I could not because I had
not any knowledge and experiences) . You wrote me , no extra software is necessary.
If I connect a cable from a computer to RS232 , should I know a special way ( pushing
a correct buttons in an order) to load anything from machine ? I have to reread all
what you have written to me, because there is a mish mash in my head. :-)
Forget the computer for a while, a pencil and sheet of paper will do the job.

you wrote :
"My suggestion is first fix hardware, enter parameters, ON/OFF, diagnostic data, and after releasing emergency stop button, if the repair was successful, the control should have no alarms.

My questions are: if I fix hardware( I do not suppose the screen is going to be
without alarm after that) 1. could I enter parameters?
2. what does it mean ON/OFF ? Power OFF, then ON
3. what does it mean diagnostic data? When you push DGNOS button, you see input state from 0 till 23, output from 48, internal I/O from 90, etc. If there is some documentation with the machine, for example emergency stop input will be something as *ESP.M, diagnostic address 21.4
4. When I should release emergency button? - After you enter all the parameters

Maybe it seems that my questions are stupid, but I do not understand almost everything
from this method of going step by step.
Probably I have to go and see the machine and try to make anything
of your advices to see what will happen , where is the access to do something... or
I do not know what else. Then I could be wiser ... at the moment , I know more , thanks
to you , but it is a little bit scrambled in my brain. :-)
Well, some step by step instructions:
1. Go to the working machine, push PARAM button, write down all the values from 000 till 99, from 996 till 1045
2. Push DGNOS button, PAGE DOWN until you find number 160. Write down all values till 223
3. Now go to the brocken machine. Put repaired board on, CONNECT THE BATTERY, push emergency stop button, switch the control on with RESET + DELET buttons hold down until NOT READY appears on screen. You will see now also the software version, like D65-12 for example.
Turn the PARAMETER WRITE ENABLE switch on the main board to ENABLE position.
4. enter all the copied data from p.1 and return the switch to DISABLE position.
5. Switch off the control, then on. DO NOT PUSH AND HOLD ANY BUTTONS now. When you see NOT READY message, release the emergency stop button, but keep your hand nearby, the machine can "jump" now.
If you are lucky, NOT READY will disappear and if there is no other alarms, XYZ position screen will be shown

[vavco]

Thanks f-bu , I had to reread all you wrote me yesterday, I did understand
more of it , now(your last advices) I think , many things are more clear for
me. Right now ,I'm still far from the machine, so I can not try anything,
(maybe I could, if I have had panel with mentioned buttons and I have made
connection from CRT to some monitor to see the result ). I want
to be prepared better if I go there. I was about to make a serial cable
according to fanuc reccomendation , you say , the pencil is enough for now.
Ok, I will check some more circuits on the main board and I go to say hello to
the machine. :-) Thanks a lot for your time devoted me and for your advices.
I'll let you know what will look like my new research.Take care, Vlado

[vavco]

Hello f-bu . I'm in the front of the machine and I'm trying to do everything what you reccomeded me .I copied all parameters from working machine, set the main board into
the machine, connected battery and all connectors. With pushed RESET + DELETE buttons
turned NC on. I was wrong when I wrote there is RAM memory alarm on the a couple days ago.What is really on it ,is :
SYSTEM ALARM No.3 D75- 14

PROGRAM MEMORY : PARITY HIGH
I can not make any step from this state, no buttons react .
Should I do anything else? Should I have to look for more mistakes in the board, in the machine or there is still any different step how to get rid off parity high?
Vlado

[vavco]

Hello f-bu once again, I had to turn Parameter switch to "enable" position
before I turned NC on(while holding reset +delete) ..... now it works , I entered all parameters and there is no error.. only, there is NOT ready message there, I found out
that I could not move axises X and Y. It seems , some of the over travel switch in
X axis is overcome. ( when I use JOG to -X direction, I see that "not ready LED"
will turn off) . So, I had no more time , I will check it later... and there was nobody
who works with this machine..., so I did not know what to check more. Maybe it is going to be ok. I would like to ask you something about loading and uploading programs via RS 232, right now it is not urgent, if I finish it, I will ask again.Thanks a lot for your help,I really appreciate it. Vlado

[f-bu]

You are welcome, Vlado, really, I had to tell you to set PARAMETER WRITE ENABLE switch on before clearing memory.