On Sun, Jan 8, 2017 at 11:10 AM, Adrian Graham <[email protected]> wrote: > On 08/01/2017 07:31, "Tony Duell" <[email protected]> wrote:
>> I don't believe it's correct as drawn. For one thing you have V333, an NPN >> transistor, with the collector grounded (and no -ve supplies on the circuit. >> For >> another, R322 is ridiculously low. And I would expect the anodes of the >> 3 diodes on the RGB outputs to go somewhere other than a resistor to >> ground. > > Hm, ok, that's today's task then. For V333 it could be that I just have the > pin numbers reversed but I'll double check. The diodes bothered me too and No, it's more than that. The emitter returns to ground too. There is no way of getting a voltage across colletor and emitter. > I'm trying to think of a better way of tracing unknown lines on the bottom > of the board. My sponge-wrapped-in-tin-foil method isn't infallible. > I've been known to test to every connection on the board. Or to desolder all the components I know it goes to and then do resistance checks to prove it goes somewhere else. Yes it takes a long time,but... Knowing what to expect, what is possible, helps a lot too. But that only comes with practice. -tony
