Date   : Mon, 27 Sep 2004 10:24:22 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Doomsday system

> I've got a service manual for the Philps monitor (from the days when people
> would pay you to fix monitors) but has anybody got anything on the laserdisc
> player ?

I've got the schematics and some of the operational theory for the
player - not the best quality (photocopies of the original service
manual) but I've used them to fix the players in the past. 

The reason I've put off scanning them so far is that all the schematics
are A3 - however one of the team at our museum does have an A3 scanner I
think; I'll see if they'll lend it to me.

One long beep and no button response is interesting - I have a feeling
one long beep is normal if the machine's taken out of standby with no
disc inside. Repeated beeps though... hmm...

Take the lid off the machine and just do a visual check for any kind of
mechanical jam. There's also a ribbon cable at the back-top running
between the tray assembly and one of the vertical boards near the PSU;
check that hasn't got damaged (it runs pretty close to the motorised
tray so I suppose it's possible). That cable carries the tray position
signals (and probably control for the motorised eject, I forget).

The players do have a built-in diagnostic mode, but unfortunately you
need to be able to put a disc into the machine, so standby and eject
need to at least be working.

> I'm an electronics design engineer so theres a chance i can fix it.

Good - I've never known a bit of kit quite like these for breaking when
you so much as fail to look at it for a few days! Tempramental doesn't
even come close (they're an amazing bit of design, just badly
implemented)

cheers

Jules