PDP8A Questions

From: Marian Capel / Jos Dreesen <jos.mar_at_bluewin.ch>
Date: Sat Nov 22 02:28:10 2003

>
> In the print set for the BA8-C the circuit that controls AC power is
> shown, the circuit uses an opto-isolator. In the schematic one side of
> the opto-isolator's LED goes to J12-B2, the other side of the
> opto-isolator is labeled OC1-2 (OptoCoupler 1 pin 2 I assume).
>
> Does anyone know where this pin actually goes?

It goes via both G8018's and G8019 to ground. It is used as an
interlock so the unit comes up only when all boards are present.
>
> =====
>
> I'm assuming that the G8019 board controls switching of the AC power
> via the opto-isolator.
>
> Is this a correct assumption?
Yes. I would guess that you have a problem on the G8019 and that the
triac is OK. Measure the gate voltage for the triac on the G8019.
Check the fuse on the g8019

One tip : the cabe that goes to the limited function panel is swapped :
line 0 of the cable does NOT align
to the little arrow on the header of the limited funtion panel.


That one took me 5 fuses to find out...

                                Jos Dreesen, just finished with the same issues on his 8A
Received on Sat Nov 22 2003 - 02:28:10 GMT