th0mas Posted February 1, 2009 Report Share Posted February 1, 2009 Hi all! Long time no talk.. I haven't forgotten about everything and everyone here though. I've moved to doing most my development on AVRs due to the GCC port availability.I *finally* after multiple years have finished my midibox SID. It took 2 SID chips, 3 recasings, 2 resolderings, but I finally have a unit that for the most part functions.. the SID was my first DIY synth and through making it and remaking it, it provided me the basis to go on an make a number of microcontroller-based AVR projects from scratch as well as build a x0xb0x :).Anyways, my SID does this weirdo thing. Peridically, maybe after 10 minutes use, it will sound "grounded out", and the contrast on the LCD will freak out so it appears that both lines are completely solid on the LCD. If I leave the unit on it will go away after awhile - it used to take a long time like a half hour but recently the glitches are shorter, like 20 seconds. If I turn it off and on it doesn't immediately fix it. Could this be a faulty/tempermental SID chip? I'm looking for someone to say "yup, I had that problem, faulty SID".. if no one does I know how to troubleshoot most everything else but I'd rather not have to start seperating my modules again to hunt for the problematic module.Thanks!Tom Quote Link to comment Share on other sites More sharing options...
m00dawg Posted February 1, 2009 Report Share Posted February 1, 2009 I would check to see how hot your regulators are getting before blaming your SIDs, particularly if it is after it's been on for a while. I generally tape my temperature probe from my multimeter to the tab of the regulator with some electrical tape. My experience has been that if it gets around 60C it could shutdown. This is by design to protect the regulator and can be avoided by adding a heatsink to the regulator. Quote Link to comment Share on other sites More sharing options...
th0mas Posted February 1, 2009 Author Report Share Posted February 1, 2009 I will give that a shot, it might be my regulator on my SID module.. however whats weird is that it'll freak out, then come back and work for hours, then freak out, then come back and work for hours.. I have a heat sink somewhere around here I can try to attach too I think Quote Link to comment Share on other sites More sharing options...
Futureman Posted February 1, 2009 Report Share Posted February 1, 2009 I'd second the regulator.My friends sequencer would 'spaz' out quite a bit. He replaced the regulator and so far it's been working just fine.(I think he damaged it when his screen was shorting on his enclosure)RegardsMike Quote Link to comment Share on other sites More sharing options...
Wilba Posted February 1, 2009 Report Share Posted February 1, 2009 I third the regulator. No way it's the SID. :) I don't think ICs temporarily go into high current drain mode... it is thus more likely the supply is failing, which means the regulator is most likely the problem. Maybe you're supplying the 7805 with a high voltage like 12V and expecting it to shed 7V at 500mA = 3.5 watts of heat. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted February 1, 2009 Report Share Posted February 1, 2009 The fact that it magically goes away if you wait kinda suggests the regulator, or I was thinking maybe the capacitors. Quote Link to comment Share on other sites More sharing options...
th0mas Posted February 2, 2009 Author Report Share Posted February 2, 2009 thanks everyone!Looks like you're in the right area.. while the regulator is fine on the SID module, i found out that my power supply intermittently supplies 8.5v instead of 5v!! I'm using a commodore diskdrive AC adapter which supplies both 12v and 5v.. looks like it's fried. I can't blame it, it's been through a lot all these years :Dedit: andd when they tell you "no user serviceable parts inside" they mean it. The whole thing is encased in resin, well off to craigslist and ebay :D Quote Link to comment Share on other sites More sharing options...
/tilted/ Posted February 2, 2009 Report Share Posted February 2, 2009 I was just about to suggest the 5v line, rather than the 12v line, as this supply is common to the sid and the LCD.Looks like I don't need to make that suggestion.and yet, I did. Quote Link to comment Share on other sites More sharing options...
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