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Flickering LCD DIsplay - Fix use a power supply


Hi Guys,

Just in case any you are suffering a flickering LCD on your cobra try using a power supply rather than USB power, fixed it for me.




I would suggest to always connect a power supply as soon as you connect something to any fez. (f.e. usb, led’s etc)


I use powered hub. Works much nicer


What kind of powered hub?
url link or picture please! :slight_smile:


Well, usb powered hub is indeed almost the same as a wall wart.

Use use this one from logitech


Any powered hub…of a known brand, not off ebay LOL


I use this one and it works fine.


I am using this one


Here is the price comparison:

Logitech 4-port hub ~$US 24.- (without Power Supply Brick)

10-port hub ~$13.60 (

7-hub ~$US29 - 40.- (with Power Supply Brick) (

Logitech is kind of pricey, 10-port hub seem to fit my budget,
I was really conviced by the video advertisement. on the 7-hub.
The one the Gus, used.
I wondered if Gus got convinced by that video too? :smiley: :smiley:


Hmmm, I have never had my Cobra’s screen flicker. Even under battery power it seems fine. Do you guys all have 4.3" screens or something?


I thinks Andy (AKA BobTheDog) has 4.3", mine is 3.5".
I’m just kind of curious about the power hub.
and just want to protect my precious Cobra.


This is not correct. It comes WITH the brick.


May be I read it wrong, but on this review page.

It said:

And I could not followed the link to Logitech buy page (the link is broken).

So I assumed that it didn’t come with the brick. :frowning:


yeah my 13 dollar one comes with one. :wink:


Ow, then there is something wrong. Those usb hubs are shipped WITH power adapter. :slight_smile:


Hmm interesting my display the 7" lcd is only flickering when I power the cobra from a external supply with 6V/1A, with USB no problem!

Has any body an idea?

The flickering comes after 10-15 minutes of running, very strange, should I use a power supply with more power?


6V is usually okay but I find it better to use 7.5V


Usually this is a sign that the power supply your using has very poor regulation. I’ve seen this same thing with the backlight with an LCD shield on a Domino. Try a different power supply.