MrHarcombe
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No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 1:27 pm

I had been happily pootling around with my RasPi under the Wheezy beta. Left it for a week or so (end of school term, so... busy) and then spotted the new Raspbian image announcement.

I grabbed that and burned it to a brand new SD card, booted up and... no response from keyboard. No CapsLock light, no light under mouse. Rolled back to Wheezy, and... no response from keyboard. I've also noticed that there's no link light for the network on either the RasPi or on the hub I'm using (which is providing a solid connection to the TV for LoveFilm).

I'm now very disheartened - I have no idea what has happened, but a system that was working fine is now unusable!

I'm using my HTC charger (as before) which claims to provide 5v/1A. I've got an old Dell USB keyboard (as before) and an Microsoft optical mouse (as before). I've tried starting it with no mouse, just to see if that helped, but no.

I've checked the voltage, as recommended on the wiki and didn't see less than 4.95v

Any thoughts, anyone? Am missing my RasiPi now the summer's here!

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Jim JKla
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Re: No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 3:44 pm

Don't you have a copy of your old Wheezy image to try?
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 3:53 pm

If both ethernet and USB die at the same moment, most often the problem is crystal X1 near the LAN8512 chip which has a bad solder joint, and one end has come unstuck.

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 5:23 pm

Jim JKla wrote:Don't you have a copy of your old Wheezy image to try?
Sadly no, but have re-burned a Wheezy image which exhibits the same problems.

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 5:25 pm

mahjongg wrote:If both ethernet and USB die at the same moment, most often the problem is crystal X1 near the LAN8512 chip which has a bad solder joint, and one end has come unstuck.
Okay... I can see a line which appears to be labelled X1 on the base. How would I tell which bit might be unstuck?

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sat Jul 21, 2012 7:01 pm

I would normally use a sharp pin, a pushpin perhaps, and with it put only a little bit of force to the side of the solderpin, if it moves its loose.
But a loose pin may not be the only cause why X1 fails, it could also have been a mechanical shock caused for example by dropping the PI, and that would be invisible.
Often what helps is re-soldering the pins of X1.
If nothing helps, and you do not get any Ethernet lights when you connect the PI to your ethernet hub or modem, then there isn't much else you can do than return it as defective.
One silly thing you could try is to keep the PI a night in a refrigerator, then try again, maybe the thermal shock will help the crystal to start up, and it may also help if you have a poor F3 polyfuse. But in your case the latter seems unlikely as you mentioned the voltage on the board is okay.

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 4:07 am

You might want to read this thread:
http://www.raspberrypi.org/phpBB3/viewt ... 24&t=11715

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 8:05 pm

mahjongg wrote:You might want to read this thread:
http://www.raspberrypi.org/phpBB3/viewt ... 24&t=11715
Thanks. I did read it, but am too inexperienced with the electronics side of things to want to risk my warranty by playing around on the board like that.

I will try to add the "lsusb" command in and see what that tells me, but I think I already know the answer...

Not looking forward to the (quoted) 5 week wait for a replacement, though!

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 8:12 pm

just to see if it indeed the crystal, you could press down on the crystal while booting your PI, to see if maybe it starts working then. Simply touching one of the two pins of the crystal (with a metal pin or other sharp metal object) might also help it start, and if you are lucky the crystal might keep working, i have seen it happen!

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 8:40 pm

mahjongg wrote:just to see if it indeed the crystal, you could press down on the crystal while booting your PI, to see if maybe it starts working then. Simply touching one of the two pins of the crystal (with a metal pin or other sharp metal object) might also help it start, and if you are lucky the crystal might keep working, i have seen it happen!
Okay, that sounds like a plan. Here's my utter electronics noob confession - I found the letters "X1" on the reverse of the board... but I have no real idea which bit is the X1 nor which are its pins to prod! Could you provide an annotated picture, please? The bit I naively thought might be X1 (the part above the label, with the clock speed etched on it) seems to have 4 connectors.

Image

Times like this, I wish I wasn't such a software geek :(

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 8:52 pm

Oops, I'm only now realising the crystal is in a different package than I thought, so forget about it having two pins, that is wrong! it has four pins, and is the metallic rectangular component above the X1 inscription (and yes, its located on the back of the board, which is why I hadn't seen it before, most pictures of the pi are shots from the topside). If you hadn't guessed, I don't actually own a PI yet. :?

Another difference is that there are no real pins you can push aside with a pin!

What is still possible is to put some force on it while booting it, to see if ethernet starts working. and to prod with a metal pin at its four contacts, to see if that helps start the crystal oscillating.

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 9:38 pm

mahjongg wrote:What is still possible is to put some force on it while booting it, to see if ethernet starts working. and to prod with a metal pin at its four contacts, to see if that helps start the crystal oscillating.
Sadly, that doesn't seem to have helped - time to get a return set up and (re)join the queue. Thanks for all the ideas - if anything else strikes you, do let me know :)

-- Ian

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Sun Jul 22, 2012 10:45 pm

Yes, the real solution/test that the crystal is to blame, is re-soldering the four solderpads.

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Mon Jul 23, 2012 7:36 pm

mahjongg wrote:Yes, the real solution/test that the crystal is to blame, is re-soldering the four solderpads.
Which is way beyond my comfort zone (even on a $30 computer). So, kudos to Farnell who responded today to my return request, and have already arranged to ship me a replacement and collect the faulty one!

Looking forward to getting back on the Pi rsn :-D

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mahjongg
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Re: No power to USB keyboard, no network link light on hub

Tue Jul 24, 2012 11:43 am

Ah, fine, so no (quoted) 5 weeks replacement after all... nice. :P

damianoloan
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Re: No power to USB keyboard, no network link light on hub

Tue Jul 24, 2012 12:06 pm

MrHarcombe wrote:
mahjongg wrote:Yes, the real solution/test that the crystal is to blame, is re-soldering the four solderpads.
Which is way beyond my comfort zone (even on a $30 computer). So, kudos to Farnell who responded today to my return request, and have already arranged to ship me a replacement and collect the faulty one!

Looking forward to getting back on the Pi rsn :-D
I was told today by Element14 China that I would have to wait 4-5 months, even after several emails. I think these companies are not unrelated, and don't understand what explains the discrepancy. I know other countries have other issues, but many seem related, or subsequent, to the same faulty component. If anyone from the Raspberry Pi side could turn their attention to the manufacturing/logistical issues, just a blog post for example, I think a lot of people would be grateful.

MrHarcombe
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Re: No power to USB keyboard, no network link light on hub

Tue Jul 24, 2012 12:13 pm

mahjongg wrote:Ah, fine, so no (quoted) 5 weeks replacement after all... nice. :P
No indeed. Colour me a happy little geek - new Pi already here, plugged in and working. Feeling more then a little spoiled, considering the wait some are facing, but not wanting to look this gift horse in the mouth!

Left it trying to install Hexxeh's Chromium package over lunch :-)

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