snoozer
Posts: 5
Joined: Thu May 09, 2013 5:53 am

PWR is on, ACT flashes once, no more action

Thu May 09, 2013 6:06 am

hi,

i have seen this state seems to be what many users experience. made the SD card, plug in HDMI, plug in power and all that happens is the PWR led comes on, the ACT led comes on miliseconds after for maybe a second and then goes off again. no output on screen and no further action from the ACT led.

so far i have done::
using 4 different types of SD cards
tried 2013-02-09-wheezy-raspbian.img and archlinux-hf-2013-02-11.img
used dd on mac and linux, used Win32DiskImager
using the composite out instead of HDMI
measuring voltage tp1 tp2 5.01 V
checked SD slot pins

in all other posts i have seen on the internet this is usully where the help stops. do i have to asume my raspbery pi has a hardware defect ?

regards
Jan

User avatar
joan
Posts: 14196
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: PWR is on, ACT flashes once, no more action

Thu May 09, 2013 7:44 am

There should be two partitions on the SD card. A FAT one of circa 60MBs and a much larger EXT4 (Linux) partition.

The FAT one is visible to Windows, Macs, and Linux. Could you post a full directory listing of the FAT partition? i.e. a list of files, dates, and sizes.
Last edited by joan on Thu May 09, 2013 7:58 am, edited 1 time in total.

snoozer
Posts: 5
Joined: Thu May 09, 2013 5:53 am

Re: PWR is on, ACT flashes once, no more action

Thu May 09, 2013 7:56 am

i have seen the files in that FAT partition and read about config.txt or what ever its called. i am in the office now but when i get home i post the list of files here.

thanks
Jan

snoozer
Posts: 5
Joined: Thu May 09, 2013 5:53 am

Re: PWR is on, ACT flashes once, no more action

Thu May 09, 2013 8:22 pm

OK, home now and here the files:

Code: Select all

pear1:~ jp$ cd /Volumes/Untitled/
pear1:Untitled jp$ ll
total 38000
drwxrwxrwx  1 jp    staff    16384 Dec 31  1979 .
drwxrwxrwt@ 5 root  admin      170 May  9 21:17 ..
drwxrwxrwx@ 1 jp    staff     8192 May  9 21:17 .Trashes
-rwxrwxrwx  1 jp    staff     4096 May  9 06:46 ._.Trashes
drwxrwxrwx  1 jp    staff     8192 May  9 21:17 .fseventsd
-rwxrwxrwx  1 jp    staff    17764 Feb  8 23:21 bootcode.bin
-rwxrwxrwx  1 jp    staff      142 Feb  9 00:27 cmdline.txt
-rwxrwxrwx  1 jp    staff     1180 Feb  9 00:27 config.txt
-rwxrwxrwx  1 jp    staff     5898 Feb  8 23:21 fixup.dat
-rwxrwxrwx  1 jp    staff     2260 Feb  8 23:21 fixup_cd.dat
-rwxrwxrwx  1 jp    staff     8687 Feb  8 23:21 fixup_x.dat
-rwxrwxrwx  1 jp    staff      137 Feb  9 02:42 issue.txt
-rwxrwxrwx  1 jp    staff  2802568 Feb  8 23:21 kernel.img
-rwxrwxrwx  1 jp    staff  9609792 Feb  8 23:21 kernel_emergency.img
-rwxrwxrwx  1 jp    staff  2694676 Feb  8 23:21 start.elf
-rwxrwxrwx  1 jp    staff   569240 Feb  8 23:21 start_cd.elf
-rwxrwxrwx  1 jp    staff  3631684 Feb  8 23:21 start_x.elf
pear1:Untitled jp$ 
forget about the three listed at the start, that's mac stuff and irrelevant for the R Pi.

Regards
Jan

snoozer
Posts: 5
Joined: Thu May 09, 2013 5:53 am

Re: PWR is on, ACT flashes once, no more action

Mon May 13, 2013 9:33 pm

ok, it's confirmed. the 1st Raspberry Pi is broken. got the new unit today and it boots up right away no problem.

if ppl have the same issue, is anybody out there that knows what the problem is ? i have the unit now since over 6 month sitting unused due to lac of time. maybe its just a matter of re soldering something ? any known weak points ?

thx
Jan

mackbreaker
Posts: 4
Joined: Sun Jun 30, 2013 9:53 pm

Re: PWR is on, ACT flashes once, no more action

Sun Jun 30, 2013 10:02 pm

Sorry for the topic kick, but i have the same problem.

i have tried 3 different sd cards, and used windows and ubuntu to create it, but the pi wont boot...
1sd card is a 16gb class 6, the other sd card is a 32gb class 10, and the other is a micro sd card 16gb class 4.

when i put in the power suply(1A) the power led turnes on, and a second later the act led flashes once.
but after 10-20 seconds the link led flashes, but not as bright, its more like a dot.

does anyone know how to fix it, or is it broken?

MrEngman
Posts: 3844
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: PWR is on, ACT flashes once, no more action

Mon Jul 01, 2013 12:25 am

mackbreaker wrote:Sorry for the topic kick, but i have the same problem.

i have tried 3 different sd cards, and used windows and ubuntu to create it, but the pi wont boot...
1sd card is a 16gb class 6, the other sd card is a 32gb class 10, and the other is a micro sd card 16gb class 4.

when i put in the power suply(1A) the power led turnes on, and a second later the act led flashes once.
but after 10-20 seconds the link led flashes, but not as bright, its more like a dot.

does anyone know how to fix it, or is it broken?
What you describe happening is what I would expect to start with, but after the LNK LED flashes briefly the ACT LED should start flashing, and if you've an Ethernet cable connected the Ethernet LEDs should light up.

However, after the LNK LED flashes there is a substantial surge in current consumption. The current increases from around about 100mA to in excess of 500mA. This will reduce slightly once the Pi has finished booting. This may be causing problems for your power supply, and so the voltage at the Pi, and I would suggest you try a different power supply. The cable from the power unit to the Pi can also make a big difference to the power reaching the Pi, the shorter and thicker the better. I would also suggest you check things out using the class 4 card rather than the class 6 or 10.


MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

mackbreaker
Posts: 4
Joined: Sun Jun 30, 2013 9:53 pm

Re: PWR is on, ACT flashes once, no more action

Fri Jul 05, 2013 7:02 am

Ok, i will try a different power suply.
but i don't think thats the problem, i've tried it already witch a 1000mah, a 700mah, and a 500mah(just to see if it would work)
but they al had a cable that was about 1,5-2 meter long.

sent
Posts: 2
Joined: Sun Aug 18, 2013 1:04 pm

Re: PWR is on, ACT flashes once, no more action

Sun Aug 18, 2013 1:32 pm

My two cents for this debug story: I'm experiencing the same problem. PWR is on (even bright!), ACT flashes once...

I've got two RPi model B's, the new one has the problem. Except with the 8Gb SD/microSD-card it came with, with the original NOOBS flashed (back) on; then it boots normally... I'm lucky to have done a dd before even using the RPi, once. It doesn't accept any of the other sd-cards, which worked fine on the other RPi.

Also already swapped and measured performance with other power-supplies and powered hubs.

The inconvenience is: my favourite distribution is not one of the NOOBS options.

Keeping this thread informed while I'm debugging. Could there be a kind of required (by this RPi) and failing bootflag?

P.S. still loving the first RPi, even due to its data corruption problems, I already have worked around, kind of.

itimpi
Posts: 1088
Joined: Sun Sep 25, 2011 11:44 am
Location: Potters Bar, United Kingdom
Contact: Website

Re: PWR is on, ACT flashes once, no more action

Sun Aug 18, 2013 3:18 pm

The problem is likely to be that the new Pi has memory chips hat are not recognised by the boot code included on the SD for the distribution you want. This is particularly likely to be the case with Micron (identified by a M symbol) or possibly Hynix memory. The answer is normally to update the boot partition with ones taken from a distribution that works using a PC/Mac (which can see the FAT format boot partition.

sent
Posts: 2
Joined: Sun Aug 18, 2013 1:04 pm

Re: PWR is on, ACT flashes once, no more action

Sun Aug 18, 2013 4:45 pm

@itimpi you just confirmed my findings. Yes, I've got a Micron memory chip. The idea of a failing bootflag (non recognized memory) was correct, in my case. Injected Raspbian '/boot'-partition into Kali's flashed image and now happily running.

But I'm not sure "this solution" is for all RPi's with "PWR is on, ACT flashes once, no more action". Guess it is the general "won't boot" signal.

itimpi
Posts: 1088
Joined: Sun Sep 25, 2011 11:44 am
Location: Potters Bar, United Kingdom
Contact: Website

Re: PWR is on, ACT flashes once, no more action

Mon Aug 19, 2013 1:34 am

sent wrote:@itimpi you just confirmed my findings. Yes, I've got a Micron memory chip. The idea of a failing bootflag (non recognized memory) was correct, in my case. Injected Raspbian '/boot'-partition into Kali's flashed image and now happily running.

But I'm not sure "this solution" is for all RPi's with "PWR is on, ACT flashes once, no more action". Guess it is the general "won't boot" signal.
Glad to hear the problem is resolved.

I believe that sometime recently the boot code was changed to produce a pattern of 8 flashes when the RAM chips are not recognised which is a much more distinct signal going forward. However older distributions probably predate this change being introduced.

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