I have a problem of opening of raspbian. I installed the raspbian and then after installing a dialogue box showed that installation is successful, after i press ok the monitor shows no signal and then i unplug and plug the rpi4 but after doing that it shows rainbow Screen and if i do nothing it shows no signal and if i press shift there is recovery and just installs it again. How to solve this?

  • 2
    What power supply are you using?
    – CoderMike
    Commented Nov 1, 2019 at 15:21
  • @Hackerman, The below official Rpi 4 power requirements tutorial might help. For newbies, a cheap wall wart of 5V, 2A is usually more than enough (But of course rich guys go for "official" 3A or higher.). And if risky you are using a cheap mobile phone charger, expect colourful rainbows first, to dizzy you, and yellow lighting bolts afterwards, to strike you! :) raspberrypi.org/documentation/faqs/#pi-power
    – tlfong01
    Commented Nov 2, 2019 at 1:19
  • 1
    You have not indicated HOW you "installed the raspbian" or what version you are trying to install. If using an old version of NOOBS this is to be expected.
    – Milliways
    Commented Nov 2, 2019 at 1:46

2 Answers 2


Despite the Comments the rainbow screen is unlikely to have anything to do with power supply - it is indicative of missing/faulty boot files.

Again contrary to comments the Pi4 does NOT REQUIRE a 2A (or 3A - as recommended) power supply - it will boot and run on a good 1A supply, although a quality (official) supply is recommended.

See Pi4 Boot Problems Sticky which will help you diagnose your actual problem.

NOTE the rainbow screen is not a meaningful indicator on the Pi4.

You are recommended to download Raspbian and follow the installation guide. https://www.raspberrypi.org/downloads/raspbian/


If it is stuck on rainbow pattern window then you are using a power source that can't supply minimum of 2A. Change your power supply and the problem will be solved. Use a power source of minimum 5V-2.5A .

  • 1
    please see this link raspberrypi.org/forums/viewtopic.php?t=55464 Commented Nov 1, 2019 at 15:37
  • 3
    You should change your answer to 'stuck on the rainbow pattern' and a Pi4 requires 5.1V 3.0A. Lets see what the OP is using for power.
    – CoderMike
    Commented Nov 1, 2019 at 15:48
  • I think 5V-2.5A PSU minimum is a good advice. 3A minimum is over selling, especially to poor hobbyists like me.
    – tlfong01
    Commented Nov 2, 2019 at 0:43
  • For my fellow poor hobbyists, I always recommend them to read this official reference on Rpi power requirements (which more or less says 2A is more or less OK for poor guys.): raspberrypi.org/documentation/faqs/#pi-power.
    – tlfong01
    Commented Nov 2, 2019 at 0:54

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