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Re: Preamp & Interposer



Hi Fernando,

Very nice that you found the problems. I guess the bad solder joints were 
good when I got the interposer and became bad after a while - I am not so 
worried about that. But channel 16 on the preAmplifier died at some point 
- you can see it dying (on March 6, 2008) in the data. As far as I 
remember we did not do anyting to the pre-Amplifier on that day but it is 
already a month ago. Maybe you have an idea what could have damaged the 
pre-amplifier because it should be avoided in the future.

Cheers,
 	Yves


                           /--------------------------------
                          /   Yves Van Haarlem
        _--~~--_         /
      /~/_|  |_\~\      /      Carnegie Mellon University
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On Wed, 9 Apr 2008, Fernando J. Barbosa wrote:

> Hi Yves,
>
> I verified that the interposer had some bad solder joints and these have been 
> fixed. The one you have should be good.
>
> I checked the amplifier and indeed channel 16 was not working. Further tests 
> revealed that the ASIC A input (for negative going signals or anodes) has 
> been damaged. The B input (for positive going signals or cathodes) works 
> fine.
>
> Because I don't have additional preamp cards, I suggest that Gerard send you 
> his preamp and I will send him yours, which he can use for his tests. I will 
> ask Elke for additional funds to produce a few more preamp cards (we have a 
> few ASICs left).
>
> Gerard, let us know if if this works for you.
>
> Regards,
> Fernando
>