Author Topic: DM1200 V243 UPDATED TO V305 NOW BLANK SCREEN  (Read 3858 times)

Offline Mike AA

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« on: December 31, 2021, 04:07:54 PM »
I guess I was a little behind on hardware files when I went to create a new display using the DM1200 for a machine retrofit. I loaded an old program using v243 after making some modifications and noticed the display would not power up. What I mean by this is, I turn on the battery master switch (ground side) and the display just sits there blank, no green led, no red led, just blank like its dead. I can pull the fuse then replace it and the display comes up like normal. I have this same display on 3 other machines and once in a while one will simply take a while to come on. I waited 10 minutes with power going to the display without swapping the fuse and there was no flash to life.

I realized I hadn't run update center in a while and saw the HWD file is now v305. I created a new program, copied my pages into the new program. Compiled and downloaded to the display, it took a few minutes as expected to move to v305 but when the Danfoss splash screen went away I am now left with a black screen. I can tell the backlight is on as I can see it go darker when I remove power. I put the previous program back on and it showed up with the fuse swap.

I thought maybe the display had an issue so I loaded the new program onto another display I have used since I first got the DM1200, this display had a working v243 program also but is powered off a 12 volt regulated supply for testing. Once I loaded the program in, again the display went blank.

I decided to see if it was simply my program so I created a super simple basic program with a simple single page. When I load the program, again its blank black screen.

Anyone have any ideas what is going on here?

I just double checked the revision history and between 243 and 305 the what's new doesn't seem to indicate anything that could possibly cause this issue.


I found the issue with the screen being blank on v305, there was a little page for doing PDF file reading and zooming. For whatever reason this must have been trying to load a file that didn't exist. Once I removed the page and reconnected defaults in the pdf reader the display loaded if power was not cycled.

I forgot to mention I am using a 24v to 12v converter. I have used them for years with ZERO issues, other than one mysteriously not working. I tried another new converter, same story, wont power up on master turn on but fuse cycle allows the display to power up. I installed a relay inline with the display positive. The relay is tied between the display power and the fuse. When the master is turned on the relay turns on then the display turns on, no timing, no special connection.

I hooked my fluke scope to the fuse output to see how clean the converter is and to see if there is some kinda spike or drop during power up, it just goes from 0 volts quickly to 12-12.2 volts. The power from the converter is quite clean, doesn't show a frequency.

I am stumped as to why the display needs anything to power up.
« Last Edit: January 03, 2022, 06:05:50 PM by Mike AA »