>> Having another look at the PCB to refresh my memory, DO >> has, and always has had, a 47k pull-up to Vcard. ISTR the >> actual recommended value is 50k >=20 > Okay, so code for missing DO low at the expected time. Hopefully I can put tomorrow aside to pull this apart and put it back together with tests like that. At least I've got something to look at now I'm hoping the mysterious occassional click will get fixed too Joe=20 ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.5751 / Virus Database: 4315/9406 - Release Date: 03/29/15 --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .