oled screen failure

All things relating to OLED Screen(s)
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2W0RMY
Posts: 1
Joined: Sat Feb 02, 2019 1:06 am

oled screen failure

Post by 2W0RMY » Tue Jul 07, 2020 7:40 pm

Hi, the screen on my mmdvm will work one minute and then not the next?
when i boot the dongle up the screen will display the message

MMDVM
starting
then it may show fusion logo but never the dmr logo.
it will work for a little bit and then just go off until reboot, where it will work for a few moments just like before.
type 3
Brightness 1
Invert 0
Scroll 0
Rotate 1
Cast 0
LogoScreensaver 1
i got rotate on because my dongle is mounted upside down.
this have been bothering me since new, please advise.

KE7FNS
Posts: 813
Joined: Wed Apr 17, 2019 11:11 pm

Re: oled screen failure

Post by KE7FNS » Wed Jul 08, 2020 10:00 pm

My guess is its probably just a dodgy OLED.

Open up SSH, type "i2cdetect -y 1"

you should see something like the following

Code: Select all

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

If the OLED board is communicating correctly one of those --'s will be something different than dashes something like 3c.

You need to test it twice, once when the board is correctly displaying information and again when it isn't. If both of your tests result in the same output, then there is nothing wrong with the OLED board. If the test during the blank output looks exactly like what I posted then the board is failing for some unknown reason. I suggest just buying a new one for a few dollars rather than wasting time trying to diagnose it any further.
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol:

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