George441 wrote: ↑
Wed Jan 29, 2020 5:50 pm
On my Pi B, I'm facing a booting problem. Greenlight is ok but Red light problem. Sometimes it is shown for 3-5 sec, then automatically off but the maximum time it did not show.
Please advise may i solve this manually or may i go to the customer care?
There is a summary of all the knowledge accumulated from these forums during the past 8 years about difficulties getting an RPi to boot, see - STICKY: Is your Pi not booting? (The Boot Problems Sticky) - https://www.raspberrypi.org/forums/view ... 28&t=58151
In particular, note this:
Check that your power supply and its USB cable is working and fit-for-purpose
This is sufficiently important that the B+ and Pi 2 PI3 and PI4 (but not the zero models) now contain a detector that signals bad power. On the model A and B the PWR LED was simply connected to power, but on later models of the Pi it is controlled by a "brownout detector" which will switch the LED off whenever the Pi receives insufficient power. The condition can also be read from software; the software can also override the brownout detector, and control the PWR LED directly. New software will now show a "rainbow square" in the GUI when a brownout event is detected. Brownouts are caused by an insufficient power supply and/or by a weak microUSB cable (one which is too long, with internal wires which are too thin). It is very important to ensure your power supply is fit-for-purpose, as brownouts can lead to SD card corruptions and boot problems. In any case, if the PWR LED ever goes out, or blinks, you have a power problem you need to solve. Note no RPI contains a battery, and so you should not use a charger, as even the best chargers are not designed to deliver a steady 5V under load, you will need a real power supply which is fit for use, note that newer models need more current than older models, the best solution is to buy an official RPI power supply, from the buying page on the blog. If the PWR LED goes out (or you get a low power warning icon) then your power supply fails to deliver good power, or you are using a power cable that is too long and/or too thin. There is one other reason for the appearance of the under-volt icon, an that is when you are stuck on the "rainbow screen" because you are trying to use old software for a RPI3B+ that is unfit for it.
Edit: to acknowledge almost identical advice posted at the same time as this...