reve Posted April 18, 2011 Report Share Posted April 18, 2011 Heeeeeey midiboxers! So in a "bah, I've wired up dozens of supplies I know what I'm doing" moment of arrogance it appears I reversed the GND and -V connections on my spiffy new AOUT_NG. Naturally it didn't work and... it took a couple minutes as I was going to fetch test equipment before I smelled something funny. I pulled the plug and TL's were hot, as was the DAC. Reading the 5630 datasheet I see it says a maximum of 7v... and with my +/-15v supply I reckon I sent close to 20v to the little bugger. Since the module is not working I'm assuming I cooked it. But before I weep my tears, I figured I should check with you lot to see if... I dunno. Maybe you guys know that DAC to be particularly resilient and I should look for construction problems before giving up on it? Or should I just dump it? If so, buying a new board might be easier than trying to cleanly desolder that chip? Advice? After fixing the power (and disconnecting the analog ground since it's shared with the core's ground) the right voltages are going to the chip but I see no change in what comes out of the output pins on the DAC. I'd never used the module before, so it could be a general construction issue. I have no tools to verify that the DAC is receiving data, but that seems hard to screw up after double checking the ribbon connector a few times. Core operates fine and I get gate signals, yay. Quote Link to comment Share on other sites More sharing options...
seppoman Posted April 19, 2011 Report Share Posted April 19, 2011 Well 20V for several minutes and a funny smell doesn't sound too promising... While the DAC is not especially easy to kill, it is quite possible to kill it (I did that myself some years ago ;)). My advice for desoldering, if you don't have special equipment like low melting point solder metal or a hot air rework station would be to carefully cut off all the legs from the DAC alongside the IC body using a sharp carpet cutter knife and gentle force. Take care that you don't apply too much force, push towards the PCB, not diagonally to keep the pads from being lifted off. As soon as the IC body is removed, you can wipe away the separated legs from the pads using the soldering iron - use moderate heat for short durations and move them away towards the IC center, not the other way round again to preent the pads from being lifted off. Good luck, it can be done, so at least try a repair before you throw everything away :) S Quote Link to comment Share on other sites More sharing options...
julienvoirin Posted April 19, 2011 Report Share Posted April 19, 2011 (edited) my advice for desoldering is to use a very thin wire like wrapping wire, passing under the legs, fixing it at the one end and pulling it while heating the legs so that the wire pass under each junction and remove the soldering (am i clear??) search for desoldering whick and flux too. adding lots of soldering can also be a solution to desolder dead IC (so that it stays liquid) Edited April 19, 2011 by julienvoirin Quote Link to comment Share on other sites More sharing options...
reve Posted April 20, 2011 Author Report Share Posted April 20, 2011 Super -- thank you, guys. Looks like I pulled up a couple pads getting the thing out... I'll get some wick, get it cleaned up and reassess. Thank you! Quote Link to comment Share on other sites More sharing options...
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