pezholio
Posts: 13
Joined: Sun Mar 04, 2012 7:31 pm

Broken a piece of my Pi

Tue Jun 05, 2012 5:22 pm

I was fiddling around with my Pi this morning and I inadvertently pulled a piece off it (circled below). At first my heart was in my mouth, but after plugging it back in, it still seems to work:

Image

My question is therefore twofold: Firstly, what does it do? (my knowledge of electronics and the internal workings of computers is limited to say the least!), and secondly, am I likely to cause any damage by continuing to use it?

Any ideas?

Cheers

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NickT
Posts: 276
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Location: UK

Re: Broken a piece of my Pi

Tue Jun 05, 2012 5:33 pm

You're in luck, it's the power supply's reservoir capacitor (C6 on the schematics). It helps supply fast occurring current demands and generally smooths out the supply voltage. It's one of the components where it looks like it should be safe to solder it back on to its mounting pads without heating up anything else too much. The Pi will work without it I suppose but it should be in circuit for greater reliability.

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jbeale
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Re: Broken a piece of my Pi

Tue Jun 05, 2012 5:34 pm

This should be in a FAQ somewhere since many people have done this! That is a power input filter capacitor, and in most cases it actually doesn't matter. It provides extra filtering for any noise and spikes on the input 5V power supply, but it turns out most power supplies don't need this. See also: http://www.raspberrypi.org/phpBB3/viewt ... f=2&t=4926

EDIT: ok, I added it to the troubleshooting page here: http://elinux.org/R-Pi_Troubleshooting#A_part_broke_off

pezholio
Posts: 13
Joined: Sun Mar 04, 2012 7:31 pm

Re: Broken a piece of my Pi

Tue Jun 05, 2012 6:41 pm

Ah, great stuff. I asked some of my electronically-minded friends on Twitter and they said as much. Nice to have some confirmation from people who are familiar with the Pi (and some interesting background reading too!).

I really should know more about the electronics side of things. As a developer, it's like being a race car driver with no knowledge of engineering!

Lorian
Posts: 112
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Re: Broken a piece of my Pi

Tue Jun 05, 2012 6:55 pm

If you solder it back on get it the right way around

Spider.007
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Re: Broken a piece of my Pi

Thu Jun 07, 2012 8:28 am

I also broke capacitor C6 off, but IMO it wasn't properly attached. Shouldn't the pins be 'in' the board and then soldered, instead of just being glued on there (using solder, but still)?

reggie
Posts: 151
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Re: Broken a piece of my Pi

Thu Jun 07, 2012 10:00 am

No, the pins shouldn't be in the board :) That is more commonly known as a surface mount capacitor, which is supposed to be soldered (Not glued!) to the surface of the pcb. You're actually expected to take a little more care around the pcb and not knock stuff off :D

Spider.007
Posts: 34
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Re: Broken a piece of my Pi

Thu Jun 07, 2012 12:03 pm

Hehe, yeah I know it was primarily my fault, thanks for the explanation. I guess I have to take my chances with a soldering iron ;)

bredman
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Joined: Tue Jan 17, 2012 2:38 pm

Re: Broken a piece of my Pi

Thu Jun 07, 2012 12:11 pm

Spider.007 wrote:I guess I have to take my chances with a soldering iron ;)
This part is only needed if you have an unstable power supply. With a good regulated power supply, it is probably not needed.

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