> On 3 Nov 2018, at 01:27, Paul Berger via cctalk <cctalk@classiccmp.org> wrote: > > Are you saying that there is a capacitor between input? output? of the 79L05 > and the ground pins of the chips? If so that would seem pretty normal as it > is usually recommended that you have capacitors to ground on both the input > and output side of a 3 terminal regulator. Are the ground pins on the three > chips you mentioned isolated from the ground of the rest of the board?
Hi Paul, The trace goes from power socket to pin 2 of the 79L05 and a small value cap which is connected to the GND plane along with pin 1 of the regulator. Pin 3 goes directly to a decoupler then straight to those 3 chips which are isolated. Today I’ll break out the ’tin foil covered sponge’ method of tracing any other points on the board that I might have missed last night. Cheers, -- adrian/witchy Owner of Binary Dinosaurs, the UK's biggest home computer collection? t: @binarydinosaurs f: facebook.com/binarydinosaurs w: www.binarydinosaurs.co.uk
