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Fried my Pi?

Posted: Sun Jul 21, 2013 10:51 pm
by TheKid
Hi,
A week after getting my Pi I accidentally tripped the polyfuse on by plugging something rated for 9V in the composite port. After letting the fuse reset itself the Pi can boot normally (The OK LED lights up) but if I plug in an HDMI cable it overheats and nothing displays. Is my Raspberry Pi okay?

Re: Fried my Pi?

Posted: Mon Jul 22, 2013 2:07 am
by klricks
It is likely your RPi is irreparably damaged.

What overheats?
Does D4 get hot? (3 pin component located between the RCA and audio jacks).

Just having an LED lit does not indicate the RPi has booted....
If it actually is booting normally as you say then you may be able to run your RPi 'headless' by remote login using SSH or RDP.

Re: Fried my Pi?

Posted: Mon Jul 22, 2013 10:55 pm
by TheKid
OK, Everything works now but the SoC overheats. Also, I am sure the pi boots because It matches the normal booting pattern.
How do I fix the overheating?

Re: Fried my Pi?

Posted: Mon Jul 22, 2013 11:05 pm
by drgeoff
TheKid wrote:OK, Everything works now but the SoC overheats. Also, I am sure the pi boots because It matches the normal booting pattern.
How do I fix the overheating?
I very much doubt that you can. Sounds like you fried the video part of the SoC. Now you get no video and the fried bit is 'shorting' power inside the SoC which is why it is overheating.

You can try to ping or ssh into the RPi. If those don't work then you are definitely wasting your time.

Re: Fried my Pi?

Posted: Mon Jul 22, 2013 11:37 pm
by TheKid
Video works now but still overheats. AFAIK everything works fine. Is the quick overheating normal? I can't compare to when it's normal.

Re: Fried my Pi?

Posted: Tue Jul 23, 2013 2:22 am
by Tage
overheats, what does that mean?
to me it means that if I touch the component with my finger then my fingerprint is replaced by a mirror image of the text that is printed on the component.
if your Pi will pass that test, perhaps you should just solder a wire across the fuse and hope for the best.

Re: Fried my Pi?

Posted: Tue Jul 23, 2013 4:30 am
by rpdom
You say that the SoC overheats. What do you call "overheating"?

Could you try the command "vcgencmd measure_temp" and post the result.

Re: Fried my Pi?

Posted: Tue Jul 23, 2013 12:43 pm
by TheKid
I don't know if my usage of overheating is correct but here's what I know:
I can't use my normal phone charger to power the Pi and the fuse trips (I could before)
My phone charger is rated at 1000mA
I can turn on my Pi off my computer's USB port (around 500mA?) but it heats up like crazy and shuts down after 5 minutes.
It also boots into some sort of safe mode.

Re: Fried my Pi?

Posted: Tue Jul 23, 2013 8:14 pm
by boyoh
Do you have a multi meter, If so do some voltage tests
On the Pi test pins T1 & T2.

1, Test with only the the power plugged in, reading
Should be 5v,( The power adapter output )
If voltage is more than 5v this could cause over heating.

2, If voltage ok, plug in externals one at a time , do voltage
tests each time, if voltage steady all ok
If voltage drops down you could have a problem.

Advice don't mess around the board with a soldering iron.
Don't do any shorting out of fuses or components

Re: Fried my Pi?

Posted: Wed Jul 24, 2013 1:08 pm
by TheKid
Hey, the voltage on TP1and TP2 are around 4.5V. Is that normal?

Re: Fried my Pi?

Posted: Wed Jul 24, 2013 1:31 pm
by thsBavR10
No! TP1-TP2 should be minimum 4.75 V!
- Try to measure the voltage between the two sides of F3 (the main polyfuse on the underside of the board):
this should be less than 0.3V (See http://elinux.org/R-Pi_Troubleshooting# ... r_problems for details)
- Both voltages together should give the output voltage of your power supply.

Re: Fried my Pi?

Posted: Wed Jul 24, 2013 1:32 pm
by drgeoff
No, that is on the low side. But "around 4.5V" isn't precise enough to give a definitive answer.