Philips CD 304 MK II doesn't mute on pause

Status
Not open for further replies.
I know that a lot has already been asked about those old Philips machines, but I have had no luck/ was not smart enough looking for the right info.

Anyway, my problem: I picked up the above mentioned player and started "to work" on it: resoldering griplets, put it into non-oversampling mode, changed caps, replaced opamps (and take signal straight from pin 1 to output (via cap). It plays very nicely,

BUT: when I press the pause button the laser stops, but the music isn't cut off - I suppose I could live with it, but every now and then putting a CD on pause can be useful...😉.

So what needs to be done? Any support will be greatly appreciated - thx in advance.

dubai2000
 
There are no muting transistors, but reed switches in those player.
The 2 white plastic with black cover around them. They look like a small transformers.

If I remember correctly magnetizing them a bit with a small magnet can
bring them back to life again.
But first I would check the soldering might be just a bad contact.
 
it has transistors, operated by the kill signal.

You need to look at the mute signal. The way it is generated is weird, via a shift register and not a direct controller pin.

And it seems to go to 7210 and 7220, so the 7210 should still mute. But i don't know what you did.

Check out the sevicemanual and start measuring and reading datasheets.
 
You mean as part of the non-oversampling mod? I followed the following description:

1. Locate the "LEG 1" on the underside of 1541 and 7220 chips
2. on 7220 cut both traces as close as possible to legs 15 and 16
3. on 1541 cut trace as close as pos on leg 1
4. using a thin wire connect the 1541 and 7220 : leg 1 to 1, 2 to 2, and 3 to 3.
5. connect the 7220 leg 23 to the other chip - the de-modulator chip 7210 leg 11.

and even:

In case of the SAA7220 and SAA7210 chips - if the mute trick does not work, you must float (isolate) the leg 11 on SAA7210 before connecting it to SAA7220P 's leg 23.
 
I am pretty surprised how much I like this player - especially after having replaced the original opamps with the discrete devices offered by SparkosLabs.
Next I might try replacing the decoupling caps around the TDA chip - if I am daring enough.
 
Status
Not open for further replies.