CNC Control Display Poor Image

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WakelessFoil

Joined Apr 16, 2020
2
I work in a Machine shop and we have a very old CNC mill from 1983 with a Fanuc 3M control. It has a CRT display that has some messed up geometry and picture. I’ve worked with CRTs of this type and tried adjusting all the pots inside to see if the image would correct. It didn’t. Any ideas on what’s causing the skewed geometry and brightness problem on one side? See image below. Input voltage seems to be correct.
 

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MaxHeadRoom

Joined Jul 18, 2013
23,390
There was a company, in Canada, IIRC, that did a conversion from CRT to LCD for some of the Fanuc's.
That is a bit of an antique now!
Some were TTL data format.
Max.
 
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Dodgydave

Joined Jun 22, 2012
10,042
Looks like flyback lines are visible caused by too much Eht on the Lopt , more than likely the tube is worn out on the Cathode.

The Geometry is caused by the Scan coils on the tube neck, they need rotating slightly, loosen the clamp first.
 

MisterBill2

Joined Jan 23, 2018
9,040
One suggestion that is safe is to try "degausing" the system, like color TVs of that same era used to occasionally require. What that does is remove the magnetization that may have built up and be causing the problem. I suggest that because it is not going to do any damage, and if it does not solve the problem nothing needs to be undone.
Beyond that, if the CNC system has a video output connector it may be possible to use a different monitor, although in that era most monitors were CGA types, hard to find these days.
 

MaxHeadRoom

Joined Jul 18, 2013
23,390
One suggestion that is safe is to try "degausing" the system, like color TVs of that same era used to occasionally require. What that does is remove the magnetization that may have built up and be causing the problem. I suggest that because it is not going to do any damage, and if it does not solve the problem nothing needs to be undone.
Beyond that, if the CNC system has a video output connector it may be possible to use a different monitor, although in that era most monitors were CGA types, hard to find these days.
IIRC that is a monochrome monitor, I have subbed a few of these older CRT types, but monitors were readily available, or from salvage as LCD's came in.
I am not sure if I still have my notes, but I seem to recall TTL style input.
The best solution is to seek out a LCD replacement vendor, if you can find one.

P,S.
@WakelessFoil OK, I still have some notes on the old Fanuc 3 system and they did in fact have a colour monitor for that model.
I have the pin out for the Honda cable connector for connecting a substitute, but the issue is finding a replacement monitor/CRT version of that size.
This on Amazon for the 10/11/12 they may have also for the 3 ?, but the price is a little steep!
RADWELL VERIFIED SUBSTITUTE A61L-0001-0074-SUB-LCD LCD Monitor, FANUC Control #00A - 10/11/12, 14", Replaces 14" Color CRT Monitor, CNC

Max.
 
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