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GLK12232 broken?
Posted: Sat Nov 26, 2005 9:54 pm
by rfhaley

I have been using a GLK12232-25-SM for many months now. The third time this happened it finally got my attention. It appeared as though my backlight had burned out but I wasn't very bothered so I let it slide. Now I want the backlight so I am investigating.
I am displaying a graph drawn as vertical lines and updating about 3 times per second at the end of a 10 foot cable. I am using RS232 and rev 1.4. Suddenly the back light fails after many hours (<10). My power comes from a 24VDC power supply through a 5 V switching reg.
The backlight LED is fine and sometimes mogd will bring it back but that is hit-and-miss because my comms are screwed up. Mogd.exe cannot even print the test message. I get a few garbled chars instead.
My environment is generators and inverters, no power lines on site.
I am set up at least 60 feet from the inverters and 3-phase generators are the quietest electrical source I know.
I have tried the manual override but no luck. Is there a deeper reset function or is my display hopelessly gibbled? So far I have damaged three units on this project. Any hints would be apprreciated.
Posted: Mon Nov 28, 2005 10:41 am
by Tom
Hi rfhaley,
When you do a manual override are you putting a jumper on the middle two pins? The manual says pins 5&6 of the keypad connector, but that is when you omit the 1st grounding pin. Please try doing the manual override on pins 6&7 of the keypad connector. About the communication situation, does the display ever lock up?
Posted: Mon Nov 28, 2005 11:52 am
by rfhaley
I caught on to the pin 6&7 thing a while back. Yes, I did that reset.
Before that I was seeing my 'no signal' message on the bottom row but about 1/4 line below and wrapped to the top of the fourth row. On a good display I see my 'no signal' on the second row and it looks good.
After the reset I still cannot get mogd to communicate properly.
I will try again tonight with a good display and mogd to be sure that part works.
Posted: Mon Nov 28, 2005 12:39 pm
by Tom
If you can get some communications, you may want to wipe out the memory and restart the download. If you have a bad backlight, email me at
support@matrixorbital.ca for some rma option.
Posted: Mon Nov 28, 2005 7:33 pm
by rfhaley
Thanks. I wiped the memory and things improved. Did I pick up some bad data perhaps?
Now power up shows a black screen except for a 1/4 block of random bits. Hopefully the random bits are not a bad sign. I suppose I'll have to learn how to upload fonts and graphics now.
Posted: Tue Nov 29, 2005 9:33 am
by Tom
Once inawhile you do get corrupt data due to the fact that the data is being exchanged back and fourth all the time. Of course it doesn't happen all the time, but as you see it happened with your module. The random bits are not a bad sign. You can upload some new fonts and graphics using the mogd software which can be downloaded at
http://www.matrixorbital.ca/software/so ... phic/MOGD/
If you have anymore questions or concerns, please feel free to post them.
Best Regards,
Posted: Mon May 08, 2006 4:17 pm
by rfhaley
Sorry, I should have responded sooner. I uploaded new fonts and my display started working again just fine.
Now it is far away overseas and being installed as part of a steel mill weld test system.
I heard today that the backlight has failed again. My bench version has also done the same thing. My display works fine but the backlight stays off.
I tried sending 254,66,0 but there is no change.
254,152,255 will not make it any brighter either.
Have I sent bad data that prevents a reset of the backlight? Power on does not light the backlight.
I am using GLK12232-25-SM Rev. 1.4
Where could I put power to the backlight and not hurt the rest of the board?
Posted: Mon May 08, 2006 4:23 pm
by rfhaley

Just like me
It started working after the second reset and as soon as I sent my last post. Thank you for the exceptionally fast service
Perhaps it was the intensity turned down to zero?