Red light, hot chip

[saulcozens]

My Pi has stopped powering up.

It was working last night, and I powered it on this morning and forgot about it until about 5pm when I noticed it was powered down (no lights).

On powering it back up, the red light goes on (but no others) and the big chip (the CPU I presume) get very very hot within about 10 seconds. During this time there is no signal on the HDMI.

I'm running standard the Debian squeeze image and have tried two SDCards


Any help appreciated

Saul

[mahjongg]

That the SoC goes somewhat hot isn't an indication anything is wrong, you simply might not have noticed it before.

Maybe you only forgot to do a normal (software controlled) power down, after first boot, which might have damaged the SD-content (always do a soft shutdown after first boot).
Or for some other reason the contents of the SD-card got damaged.
If the green LED doesn't flicker while booting, the PI cannot read the boot code, and won't show anything on screen.

My advice would be to try to write the SD-card contents anew, and try again.

Also check that your PSU is still giving out +5V, if not it might be in indication that something is indeed wrong, you should measure 5V (+ or minus a tenth of a volt or so) between testpoints on the PCB no TP1 and TP2.

[saulcozens]

'Somewhat hot' doesn't really do it. It gets finger burning hot.

But I do have a nasty habit of just pulling the power rather than shutting down nicely. So your suggestion is useful.

I'll rewrite the contents of the FAT32 partition and see if that kicks it into life.

thanks

s

[mahjongg]

Have you ever touched the CPU in working PC, even with a fan its a might hotter than you can touch!
"too hot to touch" means about 45 degrees Celsius, but chips like that can easily do 70 degrees Celsius.
Your nose is a better indicator than your finger, if it "smells like burning" there might be a problem.

[saulcozens]

You could be right. I have checked the temp of it while it was operating normally and it got pretty warm.

I usually use my lip to test rather than my nose - not sure why as it you look just as daft with a burnt lip as a burnt nose. Having said that, there was no way I was going to touch my lip to that SOC.

dd'ing a new image now - let's see if I can get this Pi back from the brink ;->

s

[mahjongg]

don't meant to touch with your nose, but to smell with it.
If any part of your body comes in contact with something hotter than 37 degrees Celsius (98 degrees farenheit) that is "body temperature" then that is a problem, especially if what you touch is conducting heat well. The reason is that at just a few degrees hooter than 37 degrees the protein that your body for a large part consist of starts to clot, just like a boiled egg. Obviously that is very bad, so your body reacts with a sensation of pain. But 37 degrees Celsius is otherwise a quite arbitrary temperature, so "too hot too touch" is an arbitrary conclusion, and so it doesn't mean anything.
Only if you have experience, and with real measuring instruments, you can make valid assertions.

[saulcozens]

LOL!