"b" wrote in message
oups.com...

BW ha escrito:

Arfa Daily wrote:
"BW" wrote in message
...

Hi all,

I bought a Philips DVP642 DVD player less than an year ago. I had been
playing DVDs and CDs nicely till a few days ago. I watched a DVD movie
on it last weekend, and after that I wanted to play some mp3s on it on
wednesday. When I clicked the eject button on it, it came out of power
down mode, and I heard a chirp sound in the speakers and it went back
to
power down mode again.

I tried it a couple of times and got the same reponse. I pulled the
plug
and let it rest for a while and tried again. Response was same!

Does anyone know where to get the service manual for it? Or does anyone
have some other tips for me? Except the advice of sending it back to
Philips. I would prefer to make it work myself if it is just some
configuration setting which needs to be reset.

Thanks in advance,
/KS


Hmmm.

Lots of advice, but not much of it very helpful.

Almost all of the Philips DVDs that I've ever repaired, irrespective of
model, have had a similar fault, and this is one of the PSU secondary
side
Schottky diodes short circuit. This may not be the case with your
machine,
and I agree with some of the other posters that, for the most part, DVD
players are not worth wasting time on, but it's got to be worth five
minutes
of your time with an ohm meter just in case.

Just a word on safety. Remember that this is a switch mode power
supply,
which is POTENTIALLY LETHAL. Do not check it or work on it live, unless
doing so on a proper workshop isolation transformer, and even then only
with
care, and beware of the main smoothing cap on the primary side,
remaining
charged, as it can do on a switcher that's not starting up. Won't kill
you,
but may result in a smashed board where you involuntarily sling it
against
the wall ... !!

When checking Schottky diodes, remember that they have a significantly
lower
forward resistance than silicon types, but will still have a virtually
infinite reverse reading. Any diode that reads low both ways should be
considered suspect, but confirm that by unplugging the PSU output plug,
as
you can be fooled by reading across the VFD heater.



Even though the Philips guarantee was for a free exchange before 3months
after purchase, I got lucky and the retailer exchanged the DVD player
with one from LG an LDA-530.

I checked the price of the LG player and it was in the same bracket as
that of the Philips one. So I'm assuming that the quality of the
components used in the LG player would be similar to the one used in
Philips. And as you say that PSU component faliure is common in Philips,
should I assume it is possible in the LG one too? The DVP-642 group on
yahoo said that the possible cause of the faliure of the unit could also
be a blown capacitor. Now taking these possible causes into
consideration, I am going to plug-in the DVD player to the power source
only when I'm using it to watch a movie, play audio, etc. I used to keep
the Philips player plugged in all the time. Even though it was in sleep
mode most of the time, but still it was being powered and working at
no-load.

Do you think this is a good approach in elongating the life of the
player? Or should I just take it in that this one won't long last either
and an year of performance would be good enough?

One of the best ways of prolonging the life of most electronics is
ensuring good airflow and ventilation. stacking amps , players etc. is
a quick way to have them run hot, drying out the PSU caps. If you must
put em in a confined space consider putting a small fan round the back
to circulate air.
Ben


I would definitely go along with that. I also would not recommend powering
and depowering switch mode power supplies all the time. Start up is when
they invariably fail, as that's the time of most stress on the primary side
components.

Arfa