Filch Posted June 16, 2010 Report Share Posted June 16, 2010 (edited) I've just completed and tested my sammichSID kit and for the first time ever, I completed a kit with no mistakes, no bugs, and no errors. I want to thank Wilba for a most excellent piece of kit and fantastic instructional writing. I think it's a testament to how well this was designed and want to thank you again. And now for one one, minor issue..... ;) MY LCD gets occasional flicker and dimming. It's slight, but noticeable. Is this normal or is there something I should start looking at as the cause? Thanks! Edited June 16, 2010 by Filch Quote Link to comment Share on other sites More sharing options...
Wilba Posted June 17, 2010 Report Share Posted June 17, 2010 MY LCD gets occasional flicker and dimming. It's slight, but noticeable. Is this normal or is there something I should start looking at as the cause? Flicker/dimming is not normal. It could be a bad solder joint in the backlight circuit. Check solder joints in that area. i.e. J16 pins 15,16 (or equivalent on LCD), T1, JR4, R4, P1, JBL. Maybe the P1 pot wiper is making poor contact. Try turning it a little. Also JR4's shunt might be making poor contact. It could also be a current supply issue, but I think you posted a link to a good PSU so it's probably not that. Check if it still happens when P1 set to 1/3rd brightness (instead of 1/2).... or if you remove the SIDs.... or if it happens when sammichSID isn't doing anything (i.e. take out the PIC). Quote Link to comment Share on other sites More sharing options...
Labelwhore Posted June 17, 2010 Report Share Posted June 17, 2010 I've just completed and tested my sammichSID kit and for the first time ever, I completed a kit with no mistakes, no bugs, and no errors. I want to thank Wilba for a most excellent piece of kit and fantastic instructional writing. I think it's a testament to how well this was designed and want to thank you again. Thanks! I totally agree, the instructions are very thorough and made completing the kit successfully a cinch! Quote Link to comment Share on other sites More sharing options...
Filch Posted June 17, 2010 Author Report Share Posted June 17, 2010 I turned P1 all the way down and I haven't noticed any more of the flickering. The screen is still plenty bright at this setting. I'll keep playing around with the sammichSID and see if it flickers again, but for now it appears to have disappeared. Thanks Quote Link to comment Share on other sites More sharing options...
Wilba Posted June 17, 2010 Report Share Posted June 17, 2010 So it could have been bad contacton the P1 wiper, or current draw close to current supply limit. If you're happy with the brightness where it is, then it ain't broke, don't fix it, nothing to see here move along.... ;) Quote Link to comment Share on other sites More sharing options...
Filch Posted June 19, 2010 Author Report Share Posted June 19, 2010 So it could have been bad contacton the P1 wiper, or current draw close to current supply limit. If you're happy with the brightness where it is, then it ain't broke, don't fix it, nothing to see here move along.... ;) I'm guessing the later, If I turned P1 most of the way up, the box would reboot. Quote Link to comment Share on other sites More sharing options...
Wilba Posted June 20, 2010 Report Share Posted June 20, 2010 That happens to me too, with some LCD/PSU combinations. Unfortunately, sammichSID design is a compromise between overall size, heatsink size, overall current draw, LCD current draw (brightness), PSU voltage/max current, parts cost, etc. Powering the LCD from the (potentially) unregulated input voltage is a big hack, but it doesn't generate more heat out of the voltage regulators and heatsink. If SIDs didn't need dual voltage, it would be a lot simpler *sigh* Quote Link to comment Share on other sites More sharing options...
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