PlanetZ forums - scopeusers.com

So one of my new used cards has some damage. When I spotted it I wondered
how this sort of thing can happen and why the card is still working...
Anyone knows what the exploded part is?

http://img26.imageshack.us/img26/3944/zwei.jpg
http://img26.imageshack.us/img26/5733/drei.jpg

It's a Scope ( 15 ) built in 2000 without IO Plate.

some kinda voltage regulator, i'd guess.

S/C can fix it.

47 uf 16 volt capacitor if i was to make a wild guess.

You have the only 13 dsp srb on this planet jan.....^^

not a wild guess, Neutron - I was about to write the same...

It's purpose is to buffer supply voltage of the DSP next to it.
If the respective DSP has few load you wouldn't even notice it's absence.
You can fix that yourself if you can handle a soldering iron.
Carefully brush off the brown substance from the circuit board - a splintered match or similiar 'tool' may be helpful.
Desolder the broken cap from it's pad and replace it by a high temperature version.
A non-SMD version probably will fit, too.
You can check polarity with a similiarly located cap at a neighbour DSP.

cheers, Tom

There is one DSP missing in my list, except from that the card works fine.



It would be nice if it can be fixed just by replacing that capacitor.
Not sure if I should try it myself though.

well, the content of the blown up cap is conductive...
probably shortens some DSP lines and disables the chip. In worst case the chip is damaged by a power-spike or shortening, but there's at least a fair chance that it survived...
as mentioned, try to scratch off the dirt with a wooden splinter

cheers, Tom

My first thought was PCB flux remover. Tom/Gary, any reasons to rule that out?

that is a cap, isn't it?

astroman's advice is pretty good.
a toothbrush and contact cleaner would probably clean that up. flux remover might be ok. i'd wash it with isohexane or similar after...
i don't think that your meter should show more than 14dsps.

I keep my used toothbrushes around for stuff like this. Great for detailing dirty equipment as well. Used usually = softer, to boot.

A mechanical cleaning, by itself, may or may not clean up enough of any conductive/partially conductive residue. It may LOOK clean but it may not take much to disable SM electronics with fine inter-lead gaps.

Here's my own meter, with similar board config. Project plus 2000-era Scope SP with 15 physical DSP chips. One of the chips does not show up in the detail, but does show up in the total DSP count.

yes, your DSP is working, on a 15 DSP card one does not show up on detail, its for "housekeeping"
my pulsar2 has 7 dsp, but who ever heard of that
and i have a actual 15, and a 14 (with a space for another) and both of them show up with 14

i get 6 and 14 and 14 (34) on the detail but 36 DSP in the total.

meanwhile i would try and clean that up and put a new capacitor on there just in case another one blows it will help absorb the surge. and capacitors age, so the total value has probably dropped a bit. i dont know how much over engineered they were though, probably quite a bit though, its German

Ok, cool. Thx for all the Info guys.
I'll try to clean up that mess and replace that cap
and let you know how it turns out.
Although I'm a little bit scared to solder around on
a expensive card like that.

cheers, jan

a toothbrush is probably not an ideal tool here - the dimension of the (enlarged) photo may be misleading
you will have to apply significant force to peel off the fried stuff (a conductive coal with minerals mixture) from the circuitboard. And you need to 'work' between the traces of the DSP which are way too narrow for a brush.

I've repaired a Macbook once that had poured a glass of red wine. Some of the delicious beverage made it's way onto the CPU board, where heat immediately transformed it to carbon (which is conductive) - dead notebook. After scratching off the black stuff it worked again.

Btw Apple's engineers were really smart: the part below the keyboard is sealed.
No fluid can make it inside...
They were even smarter by providing 2 extra 'grills' on the surface for the sensors of the automatic light regulation, to make sure the CPU could eventually enjoy some red wine ...

cheers, Tom

LederKampfwagen wrote: ...Although I'm a little bit scared to solder around on
a expensive card like that. ...

that's correct, but in this case it's just the 2 pads of the cap, which are pretty large (in relation to the rest) and on the surface.
For anything else you'd need really good tools, it's pita I wouldn't suggest at all...

cheers, Tom

thanks astro.

i really don't have a lot of experience fixing components on that scale. it's good to keep the info accurate.

Meh im not gonna do it myself... I payed 400€ for the
card and the risk that it won't work after I repaired it
makes me a scared panda. After that I would be a sad
panda and finally a angry panda. And because nobody
likes pandas I decided to ask Ralf about the costs for
a repair. 100€ minimum but I think it's worth it and
would be the best for the future of the card.

But THX for all your help

you're welcome - it's your choice

cheers, Tom

find someone that can remove the cap and suck out shorted solder, and check for burned pads on the PCB.
Solder on a new cap.

This looks like a bulk power cap for filtering the chips.

Just beware of running the board with this in the condition it is in. And get a good surge protector

I hope part of the chip isn't toasted or near-toasted. The caps are there to prevent blowing up critical active parts like the DSP's.

Greg

LederKampfwagen wrote:...I decided to ask Ralf about the costs for
a repair...

IMO it's the best solution, Man!