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T43 flicker


#1

When the whole screen is filled with black it exhibits a very noticeable flicker. I have an external 16V-2.5A power supply connected to the Cobra2 running it.

Also, I was suprised to find the same slight misalignment of the ribbon cable, identical to catalog photo, on mine; it doesn’t like to lay flat.
To help prevent snagging, can I put a spot of glue under it and, if so, is there a best kind of “electrical” glue or epoxy?
Could I also encapsulate the ribbon cable latch connector in a bubble of it?

Thanks, Jon


#2

Hi Jon,

Do you get flicker when powering from the usb socket or only only when using the external power supply?

I don’t have a suitable external power supply so couldn’t try exactly the same as you but when powering from USB, displaying a solid black background on my T43/Cobra II
doesn’t seem to have any noticeable flicker. It was the same when powering directly from the PC or an iPhone AC adapter.

My cable doesn’t sit completely flat either so guess that is just how they are.

Keith.


#3

My cheesy little hub powered from a brick, the two largest bricks I’ve got, and/or both together, produces flicker.
Hooked directly to PC, there is no flicker, and using my Galaxy charger, there is no flicker. (Simple things overlooked, thanks!)

I was expecting 2.5A to be enough for anything and find out the screen runs great with as little as 0.5A of clean power.
Does the screen need a non-switching or, otherwise specific, power supply?
Would adding filter capacitors somewhere help clean up unworthy brick power?
I have caps of a few types but I’d be guessing at the type, value, and placement needed.

Thanks, Jon


#4

Hi Jon,

Unfortunately my electronics knowledge is pretty poor (essentially non-existant) so unable to provide any assistance there.

My plan was just to use the phone AC adapter as my final power source. The label says 1A at 5v - figured that should be plenty for the mainboard, screen and a few other modules.

Keith.


#5

@ Kerbal, you may be seeing issues with the quality (stableness of voltage, at different amperages) of the output power. Unfortunately, not every regulated power supply is built equal. But you could equally be seeing switch-mode power supply artifacts as well.

Your comment about power filtering could be worth checking into. If you can make up a breadboard then certainly it’d be worth trying. I can’t imagine a linear supply rather than a switching supply would be a requirement, as Keith’s phone charger would almost definitely be a switcher. Perhaps you could try a ferrite bead over the input cable, that also may help reduce the transients?