I tried to switch on my SB3 a couple of days ago and the display didn't show anything. From the server, it looked as though everything was working as expected, but there was no sound even though the player was playing according to the web interface.
A quick google threw up the power supply as a possible candidate for the display issue. I took some measurements and the voltage held up reasonably well, even under load, so I was dubious. A known good supply brought the display back to life, however. Assuming I was now up and running again, I then realised my SB3 had another fault. The left channel was much quieter than the right. I've no idea whether the power problem precipitated this other fault, but I hadn't noticed it before so it's a possibility. Thanks to this thread, I was able to home in on the probable cause quickly. Measurements indicated that C20 had failed. Having tried a quick fix with a regular electrolytic and determined that was the problem, it also highlighted that the right channel was quiet compared to the now fixed left channel so C16 needed replacing too. I decided that as C21 and C23 are subject to similar waveforms, they may be on their way out as well so I decided to replace all four. I removed the headphone socket to make accessing C21 and C23 less difficult. The hardest part is getting the old capacitors off the board without damaging the tracks. I managed to lift one track but, fortunately, it didn't break... certainly a potential weak spot now though. Someone recommended having two soldering irons to release both sides of the capacitor at once and this would definitely be less risky to the tracks, if it bit tricky with only two hands. Getting the headphone socket off was a bit fiddly, but easy enough with judicious use of a solder sucker. I selected these capacitors as replacements - http://bit.ly/2ehag7K - as their endurance rating was better than most. Thanks to those who came before me - it made fixing this a whole lot easier than it might have been. I've attached the existing schematic updated with the SB3 component numbers. Note that the dual opamp has had each opamp reassigned to the opposite channel compared to the SB2 schematic. Raichea +-------------------------------------------------------------------+ |Filename: SB3-components.pdf | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=21322| +-------------------------------------------------------------------+ ------------------------------------------------------------------------ raichea's Profile: http://forums.slimdevices.com/member.php?userid=9678 View this thread: http://forums.slimdevices.com/showthread.php?t=71914 _______________________________________________ diy mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/diy
