i cant boot!!! rainbow screens and glitches in startup

[RedWulf]

Hello i really need some help with this.. Sorry if this has been discussed before

Whenever i try to boot my pi I either get those...

My two leds go on and no display at all,the rainbow screen doesn't come out,the rainbow screen doesn't come out with the four pixels glitching out I mean their color change or the rainbow screen may glitch with the two leds on

Also sometimes it does boot but when I try to Install any os with noobs (not lite) it glitches hard I mean lines appears on the screen the screen may go crazy and it stops I can't move my mouse or anything

Sometimes when I manage to install raspbian all I see is a blinking underscore (it used to work before)

I ve attached some images of my incredible glitches the most amazing thing is that everything used to work before it all started with raspbian underscore that made me re install oses alot of times
Well I really hope someone can help me with this
Just one advice im using noobs this also happens with noobs lite and pinn
Stay with the images...

Rainbow screen


Two leds on


Random blue screen glitch while installing raspbian and libre elec


Another glitch when installing

[RedWulf]

Someone got the solution for this ;-;???

[davidcoton]

Which model Pi?
What power supply?
What else is connected?

[fruitoftheloom]

Someone got the solution for this ;-;???

An accumulation of all known issues are in the Stickies in the Troubleshooting Section of the Forum:

viewforum.php?f=28

[mahjongg]

the video glitches are caused by transmission error in the HDMI signal, meaning the HDMI signal is too weak.
You can increase the HDMI signal strength with an entry in config.txt, or you can use a better HDMI cable (with less signal strength loss).

such glitches could possibly also be an indication of bad power.

[RedWulf]

Which model Pi?
What power supply?
What else is connected?

Raspberry pi 3 model b
Lenovo charger 5v2a
A mouse a keyboard and one pen drive

[davidcoton]

First guess is that the charger can't maintain 5V at the startup load. You may be able to see the red PoWeR LED going out, or a lightening bolt icon on screen.
If the USB power cable is separate from the charger, a shorter cable with thicker wires may help.
If you can, get the "official" 5.1V 2.5A PSU.

[RedWulf]

First guess is that the charger can't maintain 5V at the startup load. You may be able to see the red PoWeR LED going out, or a lightening bolt icon on screen.
If the USB power cable is separate from the charger, a shorter cable with thicker wires may help.
If you can, get the "official" 5.1V 2.5A PSU.

Sorry for late reply I also tried that my friend had an raspberry pi but his one is broken now so i asked if i could use his power supply still same problem .. Got any clue about what it can be??

[bratlemi]

i had a same problem. Your power input is bad BUT it's capable to run. i use 2.4A dual usb wall charger for smartphone. Cheapo, china but works.
But the main cause that i had was a bad SD card. swap it out and write OSMC image to another SD card just to see. Reason i used OSMC to test is that it's an OS after all like Raspbian but much smaller to download and faster to burn
Try and report back
And happy new year