Re: Horizontal lines after power up

Arv Evans


Horizontal lines would seem to indicate that one of the data (DB) leads 
is not making a good connection.  If you can turn the contrast down so 
you can see individual bit positions on a vertical line of dots you may 
be able to see which bit is not failing.  From this you could discern 
which lead (DB-0 thru DB-7) is not working.  That would tell you which 
wire to check.  

This all assumes that you are using either a 2-line or 4-line LCD display.
If using some other display then it might take more detective work to 
find the missing bit(s).  


On Mon, Jul 6, 2020 at 9:50 PM Jim Netwal <w9uum732u@...> wrote:
I'm thinking now that I may have a bad display.  I've checked all connections and and reheated all solder joints to the display and micro controller.  I have a QCX 40 as well so I put the "bad" display in it and same lines on that radio.  I haven't tried the "good" screen on the QCX 20 yet in case I caused the problem.  Also adjusting R47 voltage 0 - 5 volts is good.


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