On Wed, Aug 29, 2018 at 9:33 AM RETRO Innovations via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:

I stand by my original position. While I agree with Kyle that card in hand DMM efforts would likely lead to a good approximation in a short time period, ensuring a 100% correct conversion really requires building a unit and testing.

Why would ohming out this board not yield a 100% correct schematic? I see no tricky components that would confuse an ohmmeter except the address switch, which could be unsoldered. First thing I typically do is label each component if not already labeled. I'd probably prefer U1 versus IC1, and I'd label the edge connector and header probably P1 and P2. I then take an Excel sheet and place each net on its own row. So the first row could look like: IC1-7 IC2-7 IC3-7 IC4-10 IC5-10 C1-L C2-R P2-9 P1-17 As long as you're methodical and have marked every pin as visited, then perhaps double-check that no two nets actually comprise one larger net, you're done with the netlist. Drawing the schematic from the netlist is not difficult, and as long as you're using a schematic capture tool like KiCad, you can export a netlist to check against your original one, just to double-check. Kyle