pizzigri
Well-known member
ok, so I found something that worries me... essentially, in the PCC site (the only one that has info on the harness of the CC and related pinouts for the AB connector) here: https://powercc.org/takky/ there's a chart giving for pin 1 of the connector a -12V "input" (what does it mean... going out of the AB? going in from the LB? argh) in any case, this seems to be connected to a 7905, but wait! Later on, there's an image showing that you're supposed to get -10V from the onboard PS and solder a big bodge wire to supply those -10V to the connector (incidentally, pin 1), to be able to power up a 6200-6500 board.
So I have -5. -10 and -12v all on the same pin. First of all, in my replacement pcb I foolishly routed the -12v from the PSU at pin 1, following the chart, but I bet a 68K does not expect that voltage there so maybe that is the culprit. Second, there's no -5V rail (even at low amps) from the SFX PSU, so if it is confirmed that the LB needs -5v instead of -12V, I'll need to add a 7905 and reduce those -12 to -5v.
Why -5v? anybody knows?
All this will be confirmed tomorrow when I fire up the Analog board to check out all voltages.
BTW, remember everyone asking what does the BD11 connector is for? the one right next to the AB connector. Well it seems, since the ADB supply and power off (?) pins are also connected to it, like a convenient way to start the soft power when the board is out of the machine, i.e. for troubleshooting.
So I have -5. -10 and -12v all on the same pin. First of all, in my replacement pcb I foolishly routed the -12v from the PSU at pin 1, following the chart, but I bet a 68K does not expect that voltage there so maybe that is the culprit. Second, there's no -5V rail (even at low amps) from the SFX PSU, so if it is confirmed that the LB needs -5v instead of -12V, I'll need to add a 7905 and reduce those -12 to -5v.
Why -5v? anybody knows?
All this will be confirmed tomorrow when I fire up the Analog board to check out all voltages.
BTW, remember everyone asking what does the BD11 connector is for? the one right next to the AB connector. Well it seems, since the ADB supply and power off (?) pins are also connected to it, like a convenient way to start the soft power when the board is out of the machine, i.e. for troubleshooting.