Fanuc 18T led alarm

**truongtronghai** · 06-19-2018, 10:18 PM

Hi!
I have some problem about the lathe machine Hankook with fanuc 18T.
I can't power up. I check the system electric. the power supply is ok but the main board show led alarm A2. What is fault?
Fanuc 18T led alarm-20180620_073302-jpg

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**guhl** · 06-20-2018, 04:07 AM

let us know number of card which is with alarm
A20B-....-....

**truongtronghai** · 06-20-2018, 05:54 AM

board graphic A20B-8001-0821
board main A16B-3200-021
I read the maintenance book. It instruction the led alarm means " The system is stopped before the CPU is active".
Fanuc 18T led alarm-untitled1-jpg

**truongtronghai** · 06-20-2018, 06:40 AM

Mainboard Status : 0 0 0 0 ( green)
.................Alarm : x 0 x ( red )
Graphic Status : x x
.........................x x
.........Alarm : A1 x x A3
.....................A2 0 x A4
0: On - x: Off

**guhl** · 06-20-2018, 08:48 AM

did you test power supply?
if you have another one swap it
but you should have backup of parameters etc., because there is the battery in power supply

**guhl** · 06-21-2018, 02:53 AM

when I got this alarm on CPU card I cleaned all connectors on small PCBs with rubber eraser

but you should have got parameters backup before taking out any PCB

**truongtronghai** · 06-21-2018, 04:36 AM

Originally Posted by guhl

when I got this alarm on CPU card I cleaned all connectors on small PCBs with rubber eraser

but you should have got parameters backup before taking out any PCB

Thanks for your help! I have backed up the parameter and check the fuse of power supply. the all are ok. Check 5vdc 15vdc 24vdc ok

**Alhazen** · 09-17-2018, 11:45 AM

DID you found the solution?

**Richyperu77** · 12-10-2020, 07:54 PM

I have the same problem !!! Please help me

**Mattedroom** · 07-26-2023, 05:20 PM

I just had the same issue on a Mori with an MSC-518 control (Fanuc 18tc). Machine operator was changing an insert when the screen went blank and control shut off. Only alarms were as shown above.

Using the manual to trouble shoot lead me nowhere. I ended up swapping out PMC boards, daughter boards, and clearing parameters, nope.

Turns out, the driver board for the monitor died. Apparently it can cause the control to hang on bootup. I never would have thought the monitor could cause this issue. I've had monitors fail, but the machine don't stop. Our Mori uses a A02B-0222-C110 LCD monitor assembly which includes a A16B-2200-0033/01A board. The board failed. It blew a 5amp fuse on it near the 24v input. Blew the replacement fuse also. It was NOT the LCD screen or the bulb that cause the problem. It was the board attached directly to it.

I found it cheaper to buy the whole assembly rather than just the A16B-2200-0033 board (eBay). Fanuc wanted $2400 for repair (7-2023). When the used replacement (eBay) monitor assembly showed up, I got nervous because it had a A16B-2200-0053 rather than the 0033 board. Looked very similar and it was attached to the assembly sharing the same number as the original. I swapped in the entire assembly and it worked fine.

So, if anyone runs into this issue, maybe, just maybe it's your monitor's driver board.
I searched the internet and no one ever gave a solution to this problem on multiple websites, so I'm doing my part and adding to this post. Hopefully this helps someone.
-Matt