Kamis, 09 April 2009

Sony CD Player Laser/ Optic change

Finally I have replaced the old optics of my very old Sony CDP950 CD Player. That is after many weeks of frustration due to weakened laser optic (type KSS150A). Many hours I've spent to adjust the small trim pot (just below the lens assembly, on the back side), tracking & reading is getting worse every time. Hmm, it time though to look for new optic. Asked around some shops..there are no KSS150A everywhere.

the kss150A

No wonder, this little guy is older than my daughter!!, bought around 1988, one of the second generation of CD Player. In one shop one guy advising me to use a newer type, the kss210, he is a honest man, told me that some player can be replaced some not..price? less than USD 4. What the heck, I'll try that along with a new disc motor with long shaft (mine is wobbly), availability is very good here. Old motor is made in Taiwan, the new one is Malaysian made.

old disc motor

Got home and soon the Sony is in pieces.., removing the motor you'll need to desolder the board. I've marked the + and the - of the motor. Next is removing the old optic assy & install the new guy. Whew..that was easy!. The new motor is also installed as marked in the PCB.

bottom view of tray

See the green board? That's the motor PCB. The right side motor is the tray motor, the middle one is the disc spinner. Just below is the optic, the one with wires and red connector. Here is the top view.
Also the variable output capacitors are replaced, see below.

Now comes another lengthy frustration, ...got everything re connected, turn the power on, put a CD..well it's spun very well..but, where is the music?..no reading?..no time on display?. Well..its might be not as easy as I've thought, I remember the shop owner words.

I noticed that the CDP main board has many trim pots, wonder what they do?. Before I tried to trim the pots I marked them. So I know their original positions. First the trim pot on the optic..no luck. Then the rest of the pots on the mainboard. Yes, they have some thing to do with the optic head & motor speed (the servo things!), still no luck..at 3 AM I thought I'll have to say good bye to my CDP950.., pity though, they have many quality components. Nichicon Muse & Elna Duorex electrolytic capacitors, nice resistors & ceramic capacitors, there are also high quality silver mica ones. And most important..the now sought after TDA1541 DAC/ digital analogue converter.

I thought I'll go to sleep then. The next morning I need to listen to some music (I'm still felt frustrated all right), I picked up a DVD player below our TV set, hooked & put a CD and..blah!!..the sound is very harsh, tiring to hear... I thought that some tweaks will tame this USD 20 player...I really missed my CDP950..

Again, the cheapo DVD is in pieces, changed the capacitors on the power supply board, they've used a switching one, with very small transformer. One capacitor near the trafo is bulbing on the top side, waiting to burst open..who to blame? Ok. everything is re installed, put a CD and hooked back to my system without top cover. Hmm..the CD sound's stabilized now..but WAIT!!..why is the disc turns the other way as my CDP950?, this DVD turns the disc clockwise viewed from front side...could it be?..that my CDP?..or this DVD is wrong..or?

I rushed back to the Sony, desolder the motor, marking is ok, + on PCB is + on the motor (red dot)..ok, now resoldered the other way around, + on PCB is - on motor, put all things back..MAGIC!!....my CDP reads the disc flawlessly, tracking is excellent, track changing is lightning fast..so..this is my tweaking DIY audio story..really full of surprises. Next, this CDP will get custom top loading!. The tray system is not working well. But for now..welcome back my old fellow!!