Oric computers, Microdisc PSU problem

Hi,

I have problems with my Microdisc PSU: after few minutes of usage, it starts
doing a very loud noise.
Except this the power is fine, the microdisc and atmos works fine.

If someone could indicates me what could be the cause of this
"zzzziinnnnnnnnnnnn", if it's possible to solve it ?
Is it risky to use the machine with the power supply on ?

Thanks in advance.

Dbug

It could be. Where does the noise come from ?

--
Andr?Majorel <URL: http://www.teaser.fr/ ~amajorel/>
Nothing is illegal if one hundred businessmen decide to do it.
-- Andrew Young

"Andre Majorel" < XXXX@XXXXX.COM > wrote



Sounds like the plates in the transformer vibrating to me. If it is it may
be OK - or it might die.
When I've had this problem before on different equipment I've been told to
either ignore it or replace the transformer.


Steve M

> > I have problems with my Microdisc PSU: after few minutes of usage, it

Well, to be able to precise this, I should open it.

Unfortunately the last I oppened a Microdisc PSU, I was unable to refit it
into the case, resulting in the PSU dying after I plugged it back because
during the travel the solders broke... thus me trying to use the second
(noisy) PSU...

If it's like Steve is saying a vibration problem, is it risky to let the
Atmos plugged with the PSU on ?

Dbug (far of beeing an hardware master)

_If_ it's just a mechanical vibration in the transformer, I
would say it's harmless. But...

1. I find it a little bit odd that the vibration would be "very
loud"...

2. ...and that it starts "a few minutes" after power-on, as
opposed to immediately after power-on.

3. I thought the Microdisc PSU had a toroidal transformer. If
that is the case, the noise must come from something else
than the transformer, as I don't think toroidal transformers
are prone to buzzing loudly. Laminated core transformers, on
the other hand...

Toroidal ferrite core transformer:
http://mavin.com/pics/aveltore.jpg

Laminated core transformer:
http://www.ablecoil.com/photos/transformer.jpg

--
Andr?Majorel <URL: http://www.teaser.fr/ ~amajorel/>
Nothing is illegal if one hundred businessmen decide to do it.
-- Andrew Young

> _If_ it's just a mechanical vibration in the transformer, I

Very loud as "louder than the internal oric loudspeaker" !



It's perfectly silents for at least 45 seconds after power on




Looks more like this stuff actually in the oric microdisc psu.

Dbug

It's probably the transformer, then. Of course, should your PSU
explode, starting a fire in your house that soon extends to
neighbouring buildings, eventually leading to the complete
destruction of several arrondissements of Lyon, I will deny
having ever said that. ;-)

--
Andr?Majorel <URL: http://www.teaser.fr/ ~amajorel/>
Todos, todos me miran mal
Salvo los ciegos, es natural