Panel Due Fuzzy?

[Sakey]

I've just upgraded my Panel Due to the 7". All lines on the vertical axis appear to be noisy and wavy, like there made of white noise. Is this normal or have I got a broken screen?

[3D-Print]

I had some of that as well which resolved when I made sure the baud rates were the same in the Duet and the PanelDue.

[dc42]

It could be a power issue. If you have a multimeter, check that you are getting 5V between the 5V and ground input pins of the 4-pin connector on the PanelDue control board - that's the two pins closest to the mounting hole. Don't try to run a Duet+7" PanelDue from USB power to the Duet alone - the 7" screen takes around 650mA, which is more than most USB ports can supply. If you made your own cable, the resistance should be no more than 0.1 ohm per conductor. If your Duet came from Replikeo, don't use the add-on linear regulator that came with it, use the on-board switching regulator instead, but check that it is producing 5V output because I suspect that Replikeo doesn't test it.

[Sakey]

Thanks Guys,

I checked that the correct baud rates are syncs and they are (57600).

DC, I did the test and saw there is 4.78V across those two pin. Seems a little low. The panalDue board is from think3dprint3d using the cable they provided so I guessed that would be fit for purpose? Also worth noting, It's a 1.1 board connecting to a Duet 0.85 via the supplied header, did I need to change anything when connecting the 7" display that I might have missed??

[dc42]

The version 1.1 board can drive the 7" display as is, it's the version 1.0 board that needed a jumper wire added to the back of the board. Make sure you have the voltage jumper in the 3.3V position. The cable supplied by T3P3 is intended for the 4.3" display that they supply, but It's probably OK for the 7 inch. If in doubt, use your multimeter to measure the resistance.

Does the display also shimmer if you disconnect it from the Duet and power it from a 1A or greater USB power supply, such as a mobile phone charger? If so then the display is probably faulty.

I presume you re-flashed the controller with the 7" build of the firmware.

Edit: the raw 5V supply is used only by the backlight inverter, so not shouldn't matter if the voltage is a little low. I am assuming that your 7" display is the standard type that uses 5V in this way. Please check that it has a pin labelled 5V and another labelled 3.3V, and no jumper to switch the backlight to 3.3V power.

[Sakey]

I've flashed it with the 7" build ... or at least i hope I did!

Ill give it a go with a mobile charger and let you know, just noticed that the shimmering doesn't seem to effect the console > keyboard. Don't know if that helps?

Edit: Found the problem, plugged it into the mains USB charger and it turns out the amber ribbon cable on the back of the LCD when pressed down fixes the issue. Klapton tape to the rescue. Cheers DC for your help!

[Eaglezsoar]

Thanks for letting us know what the problem was!