Philips cd650 transport problem

[tubee]

sorry, you checked already, but i didn't before posting

 

[chris chiang]

CD650

I have a CD 640 manual, but this is (a little) different from your 650 i think. Unfortunately is my USB scanner offline because i'm now using a non USB Compaq, old but works fine.

With my cd 640 -2 is -9 V +/- 2 V it splits up from a transistor in -2 and -2A.

-2A goes to FTS/control display PCB. -2 to Servo pcb.

The (1N4002) rectifier diodes maybe dead,or in the connection from power supply to mains transformer is something wrong, check those wires too.

There is a small transistor between -2A and -2 also, a small BC818/16 SMD one, check if you have something like that, the BC818 maybe dead also.

The transformer has a lot of branches/voltages, maybe the branch to the PS has no AC on it? Good luck.

Hi,
After checking, I found the BC818 was damaged. However, I can't find the BC818 in Taiwan. Can I use BC817 instead?
Thanks

 

[tubee]

At the time i asked for a replacement transistor in the parts-store. They looked in the computer for an equivalent type, it was a regular to-92 one, the BC635 and works fine. You have to check the connections, Base Emitter and Collector are different, bending the feet a little and solder it on the islands, the flat side of TO92 to PCB.

But maybe is BC 817 good also, check for datasheet on the net.

Good Luck

 

[MidiMaze]

As long as the supply voltage stays within the working region of the BC817 it should work
datasheet BC817 and 818

 

[Netlist]

I’ll have an in-depth look at the schematic and the faults mentioned in this thread and will post possible solutions in the next few days.

Since the manual I have is too incomplete I find it better not to post possibly wrong information. If anyone with a complete manual would like to mail it, I'm prepared to have a second look.

/Hugo

 

[tubee]

Chris found it already, a BC818 died.