9 May
2017
9 May
'17
7:23 p.m.
Am 09.05.2017 um 18:10 schrieb Jon Elson <elson at
pico-systems.com>:
On 05/09/2017 08:26 AM, Philipp Pap via cctalk wrote:
Jon
Could you please have a quick look at the photos here
https://goo.gl/photos/m5qW1bz8kSujfK7J8 as I?m way under your skill level.
Does this look like rectifier/filter/regulator or a switching supply?
A complete schematic would make things simpler.
Thanks!!!
Anyhow, now I have 41 and 83 Volts at the 42 and
85V test points,
but always 0 Volts at the +5,-12,+12,+15V test points.
The fuses are good and the secondary transformer seems good as well.
Does this have a switching power supply for the logic (5, 12, 15V) or is it a
rectifier/filter/regulator off the transformer?
If rectifier/filter/regulator, it seems odd that FOUR voltages would quit at once. So,
I'm guessing it might have a switching supply for those voltages. It sounds like the
regulation circuit failed (display got brighter) and then a crowbar circuit tripped to
shut it down. Unless you are pretty skilled, switchers can be a bit hard to troubleshoot.
It might be easier to get a supply with the needed voltages and just patch it in.
Jon