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Pi2 Can't BOOT! ACT flashes 8 times!

Posted: Thu Apr 30, 2015 11:30 am
by iyangyoulei
Hello Erveryone!
Recently,i got into the trouble of Pi2's boot. When I turn on the power(5V2A), the Pi2's ACT LED starts flashing.It's regular. 8 Times! PWR always is on.
I have tried many SD cards within different OS. And it didn't boot either.
AND i got crazy with the Problem!!! Does everyone know what happened to my Pi2.
BTW, i am a careful person & a Chinese with poor English. So ignore my error of gramma.
THX!

Re: Pi2 Can't BOOT! ACT flash 8 times!

Posted: Thu Apr 30, 2015 12:17 pm
by drgeoff
From the "Not booting" sticky:

Other patterns that might appear during a failed boot mean:
3 flashes: start.elf not found
4 flashes: start.elf not launch-able (corrupt)
7 flashes: kernel.img not found
8 flashes: SDRAM not recognized. You need newer bootcode.bin/start.elf firmware, or your SDRAM is damaged

Re: Pi2 Can't BOOT! ACT flash 8 times!

Posted: Sat May 02, 2015 10:57 am
by iyangyoulei
drgeoff wrote:From the "Not booting" sticky:

Other patterns that might appear during a failed boot mean:
3 flashes: start.elf not found
4 flashes: start.elf not launch-able (corrupt)
7 flashes: kernel.img not found
8 flashes: SDRAM not recognized. You need newer bootcode.bin/start.elf firmware, or your SDRAM is damaged
sorry to reply so late...I have tried different cards but there was only 8-flash. and i don't how to fix it. It drives me crazy.

Re: Pi2 Can't BOOT! ACT flashes 8 times!

Posted: Sun May 03, 2015 6:48 pm
by OttovanZanten
Do you have the option to test the same cards in a different Pi 2? It's possible that the SD card reader isn't functioning.
It's also possible that the SD cards are not supported. Some work and some don't. You can google what cards are supported.
There are also fake cards, so I wouldn't get my cards if they were on sale on Ebay for way to cheap.

Re: Pi2 Can't BOOT! ACT flash 8 times!

Posted: Sun May 03, 2015 7:30 pm
by drgeoff
iyangyoulei wrote:
drgeoff wrote: 8 flashes: SDRAM not recognized. You need newer bootcode.bin/start.elf firmware, or your SDRAM is damaged
sorry to reply so late...I have tried different cards but there was only 8-flash. and i don't how to fix it. It drives me crazy.
SDRAM is nothing to do with SD cards. SDRAM is the memory chip permanently on the RPi board.

Re: Pi2 Can't BOOT! ACT flashes 8 times!

Posted: Sun May 03, 2015 7:32 pm
by fruitoftheloom
iyangyoulei wrote:Hello Erveryone!
Recently,i got into the trouble of Pi2's boot. When I turn on the power(5V2A), the Pi2's ACT LED starts flashing.It's regular. 8 Times! PWR always is on.
I have tried many SD cards within different OS. And it didn't boot either.
AND i got crazy with the Problem!!! Does everyone know what happened to my Pi2.
BTW, i am a careful person & a Chinese with poor English. So ignore my error of gramma.
THX!
viewtopic.php?f=28&t=58151

Re: Pi2 Can't BOOT! ACT flashes 8 times!

Posted: Thu Jun 22, 2017 6:52 pm
by mahjongg
There are two reasons why your Raspbian might not recognise the SDRAM on top of the SoC for older PI's, or on the back of the board for PI3's.
  1. The SDRAM is actually defective, which is very rare, as all PI's leave the factory working, but can still not be simply ruled out, as the defect can develop later, for example by dropping the PI, or damaging traces on the board.
  2. The type of RAM used is newer than the "BIOS -like" part of the GPU boot software that is part of the boot code in the FAT32 partition on the SD-card supports, so the GPU code doesn't know how to initialise the SDRAM for use.The latest software is guaranteed to know all previously used types of SDRAM, and the software will be available at least weeks before selling PI's with a new type of SDRAM (but some sellers might sell pre-written SD-CARDS and don't bother to update them when a new SDRAM type is used).
The solution for reason 1 is not user solvable, simply return your PI as defective.
The solution for reason 2 is to use the very latest release of Raspbian, but note that changes in SDRAM type are rare and are usually introduced in the BLOG, with some fanfare. SDRAM isn't simply changed because the supplier still had a batch of cheap SDRAM's available. If solution 2 does not work assume reason 1.