CDB 650 with TDA1541A S1 not working

[apassgear]

Well after all the noise with TDA1541A vs S1 I decided to test my old CDB650 but does not start.

The problem seems to be with the front control panel.

Turning on the player the platter spins for a moment and I got voltages on the main PCB. There is a power supply to the front panel of 24 V, that one also works but the display does not light up and the control buttons are dead.

I have the full Service manual for the CDP but I'm not very familiar with these type of digital control so I'm asking for help.

Most likely is a simple problem since the last time I used it was running OK.

Any suggestion where to start

[JOE DIRT®]

sounds like a ribbon cable going to the panel from the main board

[guido]

I had something similar with mine, during playing it:

stopped playing
display went dead
tray comes out

With mine it was a problem with the 24V connector making bad contact. Just bend the cabling a, must be due to taking the thing apart.

GuidoB

[Elso Kwak]

Hi,
These "Klingeldraht" [beatiful German for doorbell-cable] cables easily break of. Most of the time just in the connector. You can take apart the connector and refit the broken cable. It is not easy and it is a totally hopeless construction. Shame on you Philips. With older cables it might still not work as the connector has tiny knives that have to cut through the isolation of the cable. This may be difficult as the plastic becomes hard over time due to evaporation of the softener in the plastic...
Been there done that

[apassgear]

Thanks for the input to all you guys

I'll check those silly cables connectig all those boards. Well they have survive up to this point all my mods. I have disasembled the CDP maybe 50 times!!! during all this years. Funny but it always worked the first time after each of my ruthless changes. This shows the other side of the coin.

Will be back as soon as I check the spagetti plate

[carlosfm]

Tony,
24 volts seams a low voltage to those display types, but I don't know those cd-players inside.
Normally it's anywhere between 30 and 40 volts.
Maby someone that has a CD650 can help you.
Check from where the voltage comes, and it may be a bad zener near a voltage regulator.
I've been there, with a Marantz.

[Jocko Homo]

As I recall, the CDB-460/560/650 vintage did have problems with the IDC connectors.

As Elso pointed out, you can carefully disassemble the connector, and it back in working order. It might be easier to use a new connector, but finding a new one that size may be tough for the average DIYer.

I believe that had an LED readout, so there will probably not be anything higher voltage on it. The later models did use fluorescent displays.

Jocko

[Elso Kwak]

Hi ,
I own a Philips CD650!
The display supply is on the most right side PCB. AC comes from the transformer and is rectified on this board and regulated with a 78M24CT to +32V. (pin2 is connected through a 8V2 zener to ground to get 32 V). From there it goes to the control + display circuit.
The cable may seem OK as only the core is broken and the plastic isolation still intact. I usually pull at each lead to verify its condition....

[carlosfm]

Yes Elso, it may be that 8v2 zener the problem of Tony's cd player.
After all, he has voltage on the display circuit, so it may not be the cable!
The 24 volts he has is exactly the regulator voltage, without the zener.
And it affects the microprocessor also, so that the commands don't work, not only the display.
Believe me, I've been there.

[apassgear]

Well some more info.

Yes, what I initialy check was the voltage at the regulator, 24V.

I tested the cables from the 32V PSU and found that the red #3 pos (grd) came loose but I'm not sure there wasn't a connection before I pulled it.

Next I tested for voltage without the connector in place, at the pins, and I got 32V across #3 and #4 pins.

After reconnecting the red wire I checked that I had continuity from the end of the wire to the metal stripping female connector. reistalled but nothing again.

next I stripped part of the insulation from #3 and 4 wires to see what happened with the circuit connected. I got only 2.4V and double checked it.

Thinking I could have a short some place I observed the voltage during the shut down of the CDP but the voltage came down not very quickly at the said points.

Suggestions please???