exxos's Atari, Amiga & retro forum

HI ALL
i found the psu schematics for the TT to be vary bad
so i sympathetically restored it
and here it is
the zip contains an exported jpg from B4 and jpg after a bit of a tickle
added a few updates all done
all component values checked on a real psu...
as some components were smudged out this is fixed
was a pleasure to redraw i used online pdf to jpg
then paint shop pro to trim
then mspaint on win 10 to fix and de-grain
all done and enjoy

very good effort.

This is something worth doing to most of the old schematics. I have found a lot of the original docs faded and difficult to read.

I am doing something similar but starting from scratch on the Atri 520ST power brick as Exxos and I can not find a schematic anywhere. As I am cleaning this brick I am drawing the schematic. https://www.exxosforum.co.uk/forum/viewt ... ?f=9&t=673

I am also contemplating the VME patch on the TT but the schematics / doc is sparse and faded. If I take the plunge I will do the same as you and update the schematics.

There actually is a good copy in the download thread already, http://dev-docs.exxosforum.co.uk/PSM_534 ... 30_PSU.pdf

Makes sense to replace all versions with the best copy.

Instead of using the 2sk1117 or the original fet i will use an IRF 840, change the diodes in the bridge stage for a 3 amp bridge ,rest is the ic that drives the fet for a new one and its clamp zener on its gate pin. Three to repair all have the same ht faults.. all down to timing.. so all caps check and replace all diodes check everything including the transformer. I'll post here how the irf and fast recovery zener fair.

simbo wrote: ↑Wed Mar 14, 2018 10:18 pm Instead of using the 2sk1117 or the original fet i will use an IRF 840,

Can you please elaborate your choice for that mosfet ?

simbo wrote: ↑Wed Mar 14, 2018 10:18 pm Rest is the ic that drives the fet for a new one.

I'm not sure what you are saying there ?

simbo wrote: ↑Wed Mar 14, 2018 10:18 pm all have the same ht faults.. all down to timing..

What timing relating to HT faults ?

simbo wrote: ↑Wed Mar 14, 2018 10:18 pm I'll post here how the irf and fast recovery zener fair.