1 Sep
2014
1 Sep
'14
8:36 a.m.
I'm not familiar with these machines, never knew they existed. The Wiki
article seems to have good, basic info, though..
But what requires 325V in there - is this for the monitor?
Is it one of those situations where all of the PSU is on-board the monitor,
with the box drawing power over an umbilical - or vice-versa? I ask, as
you're just referring to "the power supply" as if there's only one to
discuss.
On Mon, Sep 1, 2014 at 10:11 AM, Rik Bos <hp-fix at xs4all.nl> wrote:
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org
]
Namens Simon Claessen
Verzonden: maandag 1 september 2014 11:31
Aan: cctalk at classiccmp.org
Onderwerp: HP 150 power supply
Hello all
Since we got 4 of them, allw ith a broken power supply, I was wondering
if
someone has already stumbled upon a solution. i
have not open them yet,
but i
think the problems are the same on all of them.
googling on
hp150 is not the way to go unless you want info for modern devices
having 150
in their names...
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
Simon,
The PSU aren't very complicated, most likely there's a shortcut on the
secondary side.
Check the rectifiers and elco's on the low voltage side, I've had 2 PSU's
with a shorted 12V rectifier.
They won't start then because the over current protection will prohibit
the startup of the PSU.
Next thing to check is the high voltage rectifier and elco's you should
measure about 325V DC after the rectifier after that check the high voltage
switching transistors for shorts.
IIRC the regulator is built from normal op-amps LM339 etc.. and not really
suspected, rectifiers elco's and switching transistors are more likely to
fail.
Be careful the 325V is deadly, of possible use a safety transformer when
the PSU is plugged in.
-Rik