Debuzzing

[Dr. H. Nikolaus Schaller]

Am 01.06.2009 um 13:16 schrieb Paul Fertser:

> "Dr. H. Nikolaus Schaller" <hns at computer.org> writes:
>>> and standby time jumping up 25% looks a lot to me.
>>
>> If you find a way to DIY to gain these 25%, please share with us.
>
> In fact overall time required for hand rework is roughly equal for
> both buzz and #1024 fixes. If one has already dismounted the can

The key difference is the word "if already dismounted the can".

>
> (quite easy if one is careful) then changing that particular capacitor
> is not a problem at all for a skilled person, it's SMT0805 size, big
> enough comparing to 0402 R and it's very conveniently located.
>
> This is for purely informational purposes for DIY-ers, i'm not
> recommending any distributors to offer this rework, quite the
> opposite.

Thanks for this description which will help DIY-ers!

Our reworker just opens the two torx screws, unclips the front cover  
and then does the Buzz-Rework under a microscope. Then, the front  
cover is clipped back and torx screws are replaced. This keeps rework  
cost low even in a high-wage country like Germany (which is still more  
than the 3 EUR we formally charge - Openmoko is sponsoring the rework).

For opening the GSM shield you have to dismantle the whole PCB from  
the Freerunner plastics and then open the can. Doing the reverse  
direction means to put the power and aux buttons in place, make sure  
that the vibramotor and speaker give contact etc.  and everything  
snaps back. This all sums to approx. 4 times as many minutes. That is  
the time that adds up in our calculation. So if we find a way to apply  
it without opening the can and dismantling the PCB, it will be the  
same speed.

So it is the simplicity of the buzz-rework that made us start this  
adventure but more complex reworks are beyond our limits...


Aother note to all who read this: the Buzz rework is only required if  
you have the Buzz problem. If your device does not, there is no need  
to rework. My personal estimate is that <5% of users have experienced  
it.

And if you don't own a Freerunner yet, you don't necessarily have to  
wait for A7 devices. So purchasing an A6 is still a good bet.

Nikolaus