Could some Raspberry Pi guru please provide hints
to my problems ? I am new to Raspberry Pi.
I bought a Raspberry Pi Model B board recently,
and a 4GB SD card. I used the Linux 'dd' command to
write 'wheexy' to the SD card. I am using the composite
video cable with a Sony Bravia TV. I am using a 1.25
Ampere output current linear power supply. Y first time
I booted with 'wheezy', everything worked fine, but the
second time onwards, the Raspberry Pi froze, at each
I then loaded OpenELEC 3.0.0 to the same SD card, but
now the board started re-booting over and over. So I
changed to OpenELEC 2.99.5, and this time, after
start up, I pressed 'ESC' on the keyboard, and this
blocked the re-boot, but the machine froze. I tried
power re-cycling the board, and the result was the
same. Now, the device has started re-booting, over and
over, with OpenELEC 2.99.5.
In all of the above, the red power LED remains steady
bright, indicating that the power supply is not
misbehaving. I have designed, built and configured
electronic equipment for almost 2 decades now, but
I am clueless as to what the problem might be. Any
hints, suggestions would be of immense help. Thanks
in advance for your help.
If it booted properly the first time using Wheezy, perhaps it would be
worth trying that again as a first step. It might be that you changed
something in that first run that damaged the image.
If that doesn't work, I would try another SD card. I have found that some
cards fail in the Pi after several boots, although they appear to still
work as storage devices in a camera for example.
if that were a hard disk, Id say it was gone missing in action.
Definitely worth trying another SD card.
(in-ep-toc?-ra-cy) ? a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.
I had all kinds of trouble getting an XBMC release to work on a RPi B model
2. My trouble turned out to be power even though I was convinced it
couldn't be (and was getting furious at the various web sites and fora that
insisted it was.) I was using a recommended-for-RPi 5V 1A switching wall-
wart power supply, and when I finally put voltmeter probes across TP1 and
TP2, the supply was only delivering a hair over 4V. Using my own 5V
regulator box fed by a 12V 1.6A wall-wart is allowing things to go. Raspbmc
is loaded and running.
Symptoms were: live HDMI screen but dead keyboard and mouse, dropping
ethernet connections, even read failures on the SD chip. The power light
was always lit, but didn't mean anything.
I mention this because I remember how sure I was that power was NOT the
problem. You probably should do some organized tests to rule out power
trouble, or confirm it.
Good Luck, Mel.
I learned from 3.5in floppy discs that unbranded media are usually a
waste of time and money. With cameras, sound recorders, and now the Pi,
the same names keep coming up as reliable: Sandisc, Integral, Lexar come
As someone else suggested, check the supply voltage.
Usually the problem in such circumstances is not the power supply, but the
micro USB cable to connect it to the Pi. I cut open a 'genuine Nokia' cable
(obtained from eBay) which turned out to have no screening and about three
strands of hair-thick copper inside. An 'official' Pi USB cable from
Farnell was much better.
I know the importance of the power supply. I am using
a 5V 1.25 Amp power supply. As a test I soldered two
leads near the output (just before the output USB
socket) and during boot up, the output voltage varies
between 4.88 and 4.97 V. I then tested at TP! and TP2,
and the voltage was identical. As an alternative, I
changed to a another power supply with current rating
of 3.5 Amps and the behavior of the Raspberry Pi was
You're right. That sure looks ruled out to me.
(I have bad karma lately for power. Just now a circuit with an AVR and a
PIC and a little audio amp took to going wild. As it happens, the battery
had exhausted to the point where with loud noises the regulator couldn't
maintain the PICs brownout reset voltage. But that's off-topic here.)
One of the problems with just measuring the voltage with an ordinary meter
that current spikes which could cause a significant brief drop won't be
registered. This is particularly relevant if the connecting lead is rather
long or very thin.
These spikes shouldn't really occur as the on-board filtering should deal w
them, but what should happen and what does happen are not necessarily the s
That is true, and adds to the confusion. A lot of
Raspberry Pi Web sites recommend a power supply
with current output rating of >= 1 Amp. So, as
one of the other posters have stated, one is
left with no option but to short out the
... unless the fuse is effectively a slow-blow type, where it
will let higher current flow for short durations. If that is the
case, the power supply would have to be capable of supplying the
peak current, but the fuse would be rated for the average
One reason for using an overrated power supply is to improve regulation.
The supply will only supply the current demanded by the equipment
connected to it, so a 5V, 15 amp supply will only be supplying 500mA?
when the Pi is connected. It has 14.5 Amps in reserve, so you could
connect up to another 29? units to it.
Unless the connected equipment is badly designed, and having an input
fuse that is too small is an elementary error, you shouldn't need to,
and in fact shouldn't anyway, bypass any internal protective fuses. If
the internal fuses are blowing, that is an indication that the fused
unit is either faulty, badly designed, or has been modified in a badly
thought out manner.