KCS - Blank Screen

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stevieboy84
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KCS - Blank Screen

Post by stevieboy84 » Wed Apr 15, 2020 6:54 am

Hi there.

I am having a similar issue to this post: viewtopic.php?f=51&t=9270

A couple of differences, so I thought I'd create my own thread for this as you already resolved the other person's issue.

I'm running the 1.3D board with CM3+ module, which I purchased a little while back but am finally getting around to building.. I also have the 640x480 screen.

I've been following the steps closely in the wiki and got to the point of attaching the screen, but when I switched it on, the backlight lit up, but nothing else happened. All the status lights look fine. I quickly realised I hadn't set the config.txt to have the correct screen resolution, so updated that and retried, but to no avail. I then went to the FAQs and saw the section about the 640 screen. I am using a v1.3D board so didn't need to do any software/microcontroller updates, however I did solder bridge the two contacts as per the instructions.

Doing all the above didn't seem to make any difference so I followed the diagnostics from the post mentioned earlier:

With 640 screen plugged in:
c17 19.6V
c59 19.6V
other chip: 19.6V

without screen:
c17 34V
c59 34V
other chip: 34V

I didn't write down the voltages so the without screen volatages are from memory, but they were in that area.

The 320 screen also has the same behaviour, backlight but nothing else...

Here are some photos of the board in various states:
https://imgur.com/a/1tsKNQn

stevieboy84
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Re: KCS - Blank Screen

Post by stevieboy84 » Wed Apr 15, 2020 3:44 pm

Just wanted to follow up with some extra information from some tests I did tonight.

I fortunately bought two kits at the time, so I got the 2nd kit out as that was unopened and decided to do some diagnostics without doing the soldering step for the 640 screen.

Here is what I found:
  • Board 2 with unused 320 screen and default config - works perfectly fine
    Board 2 with 320 screen from kit 1 - very faint image can be seen from the test mode colour image
    Board 2 with 640 screen - bright vertical coloured lines on screen
    Board 2 with 640 screen and 640 resolution in config enabled - no image


I wanted to test the working 320 screen on Board 1, however I'm scared to plug that in just in case board 1 is killing the screens..

Look forward to hearing from you!

Thanks

stevieboy84
Posts: 11
Joined: Thu Jan 10, 2019 1:08 am
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Re: KCS - Blank Screen

Post by stevieboy84 » Tue Apr 21, 2020 4:02 am

Just to update here. I reached out to Kite and after some diagnostics, it seems to be two faulty screens (640 and 320). Just waiting to hear about getting replacements.

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