Raspberry Pi LCD issues, graphical errors and banding

[Duhjoker]

Ok guys I decided to start a new thread since the OG thread contained more non-sense than actual useable info. That's my fault I'm a lil bull headed. Im hoping to maybe make this thread universal for any one having LCD issues so we can share our problems and fixes.

I'm having problems with banding and negative colors with my waveshare spotpear 4 inch LCD. When booting the Pi the "OK" checklist starts the color is perfect till it gets to the login part then the command prompt is blue instead of green and purple. Starting Xserver gets this kind of stuff...........



So here's what I have and what I'm trying to do. I have a Pi 3 in which I have modified it by removing the top halves of the two double USB ports and completely removed the Ethernet port from the board. This was done very carefully and methodically. I have also shortened the gpio pins and soldered a red wire to the Gpio 5v pin and a ground on one gpio ground pin.



These are my parts:::

Pi 3

Pi zero DIY USB hub

1x 3600 mah 3.7v lipo

1x 1000 mah 3.7v lipo

DROK 5v 3A step up

Mini USB 5v 1A 3.7v lipo charger

Keyboard/mouse dongle

4 inch waveshare spotpear (3mm shaved off the female header)

20x20x6mm 30ma 5v fan



Here's a pic of the female header on the 4inch LCD. As you can see the pins are tight and have good connection.



I put it all together by soldering the battery leads to the charger then extra leads running to the input of the 5v 3A step up. Then running the -negative wire to the previously soldered negative pin down on the GPIO. While positive runs to the switch with the fan attached and running to the 5v pin on the gpio. There are also leads soldered the underside pins of one the removed top half of the USB for my DIY Zero USB hub.




Programs installed onto SD card are.....

Raspbian Jessie 5-10-16

Minimal kiosk browser------internet, videos, music etc

Omxplayergui--------------music

Emulationstation/Retropie and all its bits------------gaming

SDL2--------------------------------------gaming using the LCD

FBCP------------------------- frame buffer for games and video and Xserver

Sudo apt-get install::

Uget---tint2---Vic---xterm---update---upgrade---dist-upgrade---YouTube-DL---


To begin with the issue as I recall started with my Pi 2 and the 4inch LCD after the 3-18-16 up date to Raspbian Jessie. I made a thread back then for it on trouble shooting but no one ever bit. I then bought a Pi 3 thinking it might fix the problem.

After much bull-headedness on my part we discovered first that I wasn't getting enough amperage through the powerboost 500 or 1000 due to the Pi 3's much higher energy needs. So I bought a DROK 5v 3A step up with the thinking that 3A should be more than enough.

It does get the current it needs judging the red light on the Pi but that did not solve the problem. Just to be sure I have switched my SD card and 3 LCDs (2.8, 3.5 &4) to all my Pi's 3, 2, & zero. With every system and LCD having the same graphical errors.

I have also changed the bit depth to all between 8 and 32 using "fbset -depthXX" and checking it by using "fbset".

I have also tried using the waveshare wiki's raspbian image to no avail.

[Duhjoker]

Is there not a way to check the pi for proper working condition with out using the screen?

Im at buying a new pi and screen since both mine are mechanically working. I hope im using that word correctly. I mean that everything is making proper contact.

If i could test the pi somehow that would save money if its not damaged and just need a screen.

[Duhjoker]

Ok what i did today was remove the lil plastic clip from the male pins on the gpio. This way i dont have to remove anything from the new LCD to keep the low height.

[Duhjoker]

I oredered both a new Pi 3 and a new 4inch screen.

In order to send proper power through the board i will have to solder leads to the 5v gpio and i would like to ask where would be the best place to solder the ground.

On my current i used one of the gpio grounds but that may not be best.

Should i start out with a freshly image burned SD card or start with my current.

Was there any way i could have made the screens act the way do by the modifications i made to the board?

[Jednorozec]

Are you enjoying talking to yourself?

[Duhjoker]

Not really. Was hoping someone would chime in at some point. I would like to get this done right.

[blaablaaguy]

Was there any way i could have made the screens act the way do by the modifications i made to the board?

Metal dust from the hacksaw/stray clippings from the gpio pins/balls of solder shorting something out? Cant think of any other reason

[davidcoton]

I oredered both a new Pi 3 and a new 4inch screen.

Why? Did you break the first ones?

In order to send proper power through the board i will have to solder leads to the 5v gpio and i would like to ask where would be the best place to solder the ground.

On my current i used one of the gpio grounds but that may not be best.

"Proper power" does not depend on using GPIO rather than the intended supply points.
Use the USB power input, or the test points connected directly to it. That way you won't bypass the protection circuits on the Pi.

Should i start out with a freshly image burned SD card or start with my current.

Probably fresh. Even you don't seem to know what you have done to the previous image.

Was there any way i could have made the screens act the way do by the modifications i made to the board?

What modifications? I'm not about the wade through your walls of text to try to find what you did, undid, redid, or ended up with.

Was hoping someone would chime in at some point. I would like to get this done right.

Well, if you actually listened to some of the suggestions you were given, instead of just doing your own thing, people might be more prepared to offer more suggestions.

[Duhjoker]

I don't think I broke any Pi but since we can't figure out what's wrong with the LCD and its banding and negative colors with any of them so I wanted to start with a new Pi.

All the modifications I made to my Pi 3 and LCD are listed above at the main post.

Those test pads are tiny!!! Could I use the positive test pad and a ground where ever. I'm not an expert solder and Im afraid I'll end up shorting them with solder.

I fully admit as stated above in main post that I was being bull headed and I apologize. I'm ready to listen to and use any suggestions.


Thanks guys!!! I really appreciate the help.

[Duhjoker]

My new pi 3 came today and im seeing something kind of weird.

My first pi 3 came in a purple box this one came in a red box.

Should i be worried about it being counterfeit?

[mthomason]

I think the box color is down to manufacturers - doing a google image search, I see red ones badged Element 14, and purple ones badged RS.

[Duhjoker]

Awesome!! Thank you!!!!

[Duhjoker]

Ok so i added the old screen to the new pi and same problem.

Guess that means it wasnt the pi 3 causing the problem.

Also..... I uh halfway hooked up the power. I had the output of my 3a step up running solderless.

I think i know what the problem is why i cant get proper Amperage through my cords. The lil Micro USB cords have tiny lil wires. I dont think they can handle it.

When i hook up the output of my step up to the test pad using thicker wires it works fine. No flashy red light.

[mthomason]

D'oh, I can't believe I didn't think of that earlier. Yeah, cable thickness could well be an issue at that Amperage.

You're still getting the graphical corruption even with thicker cables, though?

[Duhjoker]

From what im seeing leaving it on briefly its still got the graphics issues.

When it boots up every thing is the right color till it gets to the command prompt which then turns blue or purple depending on the viewing angle.

[Duhjoker]

Does any one know a simple way to test the amperage coming out of the step up with a multimeter?

Ive tried a couple things but im just not getting a reading.

Also i managed to solder a wire to the PP2 and set it up with the thicker wires coming from the step up. The red light comes on stays on but the screen still acts the same.

[davidcoton]

It's not entirely simple.

You need to connect the power supply output to a dummy load (and nothing else), then measure the voltage across it.

For a 5V 3A supply, the load needs to be 5/3=1.66 ohms, and capable of dissipating 15W for long enough to make the measurement. That is a non-trivial resistor!
The voltage should remain near 5V, certainly above 4.75V. You also need to know that your meter is reasonably accurate at 5V -- compare its reading with one or two other meters.

[Duhjoker]

My new 4inch screen should arrive tomorrow and I'm hoping every thing will work but I've got my doubts.

This is the main reason............





The top pic is of raspi-config using the screen. As you can see it looks great with no issues.

The bottom pic is of the command line after booting up. As you can see the [OK] are perfectly green but when looking at the prompt it's a lazy blue color instead green and purple.

[blaablaaguy]

My new 4inch screen should arrive tomorrow and I'm hoping every thing will work but I've got my doubts.

This is the main reason............





The top pic is of raspi-config using the screen. As you can see it looks great with no issues.

The bottom pic is of the command line after booting up. As you can see the [OK] are perfectly green but when looking at the prompt it's a lazy blue color instead green and purple.

What if the bottom only the bottom half of the screen does that to the green colour? You could try inputting random commands to get the prompt at the top to check.

[Duhjoker]

Ok my new 4 inch screen came today. So yay!!!!

The first thing I did was attach a he LCD to my NEW Pi 3 and added power to the two lil wires I soldered to the test pad and gpio. It booted up great but I'll re-Burn raspbian I guess.

Any way the good news is that the NEW LCD works just fine.

I also tested the power while I was at it using both my installed power wires and the charge system. There was no change. Every thing worked fine. So I also tested my OLD Pi 3 and got the same results.

So every thing is working now. Thank you sooooo much for the help guys. I apologize again for being an &$$. And I really do appreciate all the help.

I'm hoping that this thread will grow a lil bit so we can have a specific thread just for LCD issues so people can find answers here.

[Duhjoker]

How can i fix the task bar in LCD mode. Every thing is jumbled together at the top.

I was looking at my first pi 3 and i must have knocked the wifi antenna block. Can that be easily soldered back on? How do i know whar to buy.

What do we do with our old pi's? Can they be re-furbished?

[Duhjoker]

Got every thing going!!!!

I moved everything to a slightly shorter case i had started months ago and stopped. But in doing so i lost 500mah of battery capacity so im down to 4600mah.

Still had to modify the pi 3 though i took more care testing it constantly.

Managed to fix my pi zero usb hub too so now i have 5 total USB ports.

I built in a slanted SD card port to for the ease of a quick card change.

I also made openings for the main power micro USB and the HDMI.

Lastly, i noticed a few nights ago when the lights were off that the lil blue light on my step up was glowing while not plugged in to the pi. So it was dispelling power even though it wasnt being used. That was quick fix that involved changing the position of the switch from between the pi and the step up to between the step up and the charge unit.

Funny thing my charge system. I did not think i could charge and play at the same time since my chargers amperage is at 1A. But it works.

So what did i learn?

#1 Don't be an ass!

#2 listen

#3 always check that your pi is getting the proper amount and rate of power.

#4 DO NOT try to alter your LCD's female header!!

Wow though!!!! The graphics are awesome!!!! Every thing looks so much cleaner and sharp than my Pi 2 or Zero ever was. My H.R. Giger print i use as a background is just beautiful!!!!