ASTEC 8151 PSU (TRS80, Osborne etc)

[Jules Richardson]

On 10/23/2016 08:02 AM, Adrian Graham wrote:
> Hi folks,
>
> Now that the bouncing has calmed down I've got a question about this here
> triple output pretty ubiquitous power supply. This one had some burst caps
> so naturally wasn't working and was probably why the machine it came out of
> was taken out of use.
>
> I've replaced all of them because why not, along with the .1uF mains
> filtering cap that would also burst at some point and I still get low output
> on all rails.

Low output in-circuit? If not, are you using a large enough dummy load 
(probably just necessary on whichever output rail is deemed to be the main 
one)?

Without enough load the regulation on switchers often doesn't work, and low 
outputs are a typical result...