Component fallen off a scope board

[mrgrateful]

Unfortunately the story has a sad end.

I made sure all the DSP legs were separated:

http://homes.stat.unipd.it/mgri/board_damaged_6.jpeg

Then I resoldered the capacitor:

http://homes.stat.unipd.it/mgri/board_damaged_7.jpeg
http://homes.stat.unipd.it/mgri/board_damaged_8.jpeg

When installing the board, I get the error "timout waiting for acknowledge from dsp 0":

http://homes.stat.unipd.it/mgri/board_damaged_9.jpeg

I guess this is the end of the story...

Matteo

[astroman]

don't give up too early !
are you absolutely certain that no solder slipped between the DSP legs ?
it needs only a very small portion (vaporized to the surface) at such high frequencies - scratch with a needle (as suggested by Flux) between the connectors.
Sometimes this message pops up erroneously and there's still a chance the board is working as a 2nd card.

cheers, Tom
(fingers crossed)

I've checked the pinout: the damged part is 3 data lines between 2 ground lines, no physical damage (of the chip) to be expected by these.
At a 2nd sight you may remove the cap again to make sure no solder slipped aside from the pads - it looks so.

[garyb]

it IS still fixable at any rate...

[mrgrateful]

Hi. Thanks for all the support.

I didn't even try to solder the DSP legs. I don't think I have the right tools. The tip of my soldering iron is too big and have no experience in doing this kind of job. If you could point me to any web page which explains how this can be done with a soldering iron, I will be more than happy to try.

I am going to be away from home for some time now. When I come back, I will try again to fix this card. Thank you all for the suggestions and great advice. I think I will need it again soon!

Matteo

[astroman]

the item is very small, so on the pic it looks like soldered, but you just bent the legs of the DSP.
Of course you don't need to solder them if they are not broken, which it looked like on an earlier pic.
The 'communication error' points in that direction, but I've seem the same occasionally on my system, too.
Under various circumstances from install problems to temporary malfunction - the latter usually cleared by a reboot.
You can measure the resistance with 'needle' multimeter tips:
one on the soldering pad and the other one close to where the leg leaves the chip's body.
Should be zero Ohm of course.

An impact may have pressed some solder or metal parts between the DSP legs, that's why it's a good idea to scratch with a needle between the pads.

Normally you solder such stuff with hot air, but that's way to expensive to aquire for such a single operation
Improvising is more or less let some solder run down those 3 or 4 legs and suck away what's too much with 'hairy copperwire' (dunno the proper name, it's sold specifically for the purpose of desoldering)
Of course one has to be very careful and doublecheck with a magnifier - but it's no black magic either

cheers, Tom

[Cesax]

ciao Matteo
hai risolto il problema con la scheda?
mi ricordo che avevi fatto un'offerta x la mia su ebay............anche la tua l'hai presa li?

[rebornonline]

I didn't even try to solder the DSP legs. I don't think I have the right tools. The tip of my soldering iron is too big and have no experience in doing this kind of job. If you could point me to any web page which explains how this can be done with a soldering iron, I will be more than happy to try.

You'll be happy to know that the easiest way to repair this is with a standard size soldering iron. The technique you need to use is called "flow soldering". The process is the reverse of normal sodering : You basically stick a load of solder on the legs, which as expected sticks them all together, the art is in removing the excess solder, once it's removed all you're left with is a load of perfectly soldered legs. I can't find any vids or anything, but have a Google around. I've been meaning to do a video of flow soldering for a while, maybe now is a good opportunity :o)

EDIT : Here's the kind of thing
http://www.youtube.com/watch?v=auI0tnYzcBc

This guy is actually using braid to get rid of the excess, which is easier, but with practice you don't need braid. :)

As for the cap, i would suggest soldering two individual strands of wire to the legs on the cap, then soldering those to the pads on the PCB, you can then glue the cap back in place.

[mrgrateful]

Hi, thanks for all the useful advice. Sorry it took me so long to reply. I tried to solder the broken legs with a standard soldering iron (thanks rebornonline for the suggestion). In particular, I followed the tips given in this video that details soldering of SMD components:

http://www.mygsmtube.com/Videos/119-how ... onent.html

However, I don't think this is applicable to my case: the DSP legs are too close together. In fact, I tried to resolder them with my standard soldering iron and... I did a mess:

http://homes.stat.unipd.it/mgri/board_damaged_10.jpeg

The videos on this subject show how to solder SMD components with legs much more separated. Also, I didn't simply have to solder the DSP: I had to re-solder its *broken* legs! This is much harder. So, I guess that I learned (the hard way) that this can't be done (or at least I can't, with my standard tools) on Creamware cards.

I then sent the board back to Sonic Core, asking them to simply transfer all the software to a Luna II board that I already had. They kept the 15 DSP board and kindly (Ralf, in particular) transferred the software (for free).

A lesson I think I learned is that more cards with a smaller number of DSP's is a preferable setup. Due to a broken DSP I had to give up 15 of them. So, a more modular system is less risky (especially when using older hardware). Also, these 14 or 15 DSP cards are really huge! The 15 DSP card hardly fitted in my computer case.

I hope the lessons I learned are useful to someone else in this forum.

Thank you all for the support! As I already said, I think the support given by people in this forum really adds a lot of value to Creamware cards.

Matteo