Reviving Sony D-90

serge1996

I got so excited by kaosun writeup on Toshiba player that, for this once, have decided to calibrate my D-90 the way it should be done. Borrowed the 'scope from the lab but no matter what I do, I just cannot get anything better than blurred and totally non-cynced image. CD plays beautifully, so I am running out of ideas... Disclaimer: I have never used these newer scopes in my life
Any thoughts?

kaosun

1: It seems your RF amplitude is 0.75Vp-p is right. Be aware of the Rf for CDR is 0.8Vp-p and 1.2Vp-p for commercial CDs. You can adjust the oscilloscope to align the pattern at the middle of the screen and make it larger.

2: Be sure to replace all the DIP capacitors whatever they're good or not. Furthermore, clean the PCB after removing the capacitors.

3: Follow the service manual to ensure the several voltage points have correct measurement and adjustment. Also, adjust TB and FB to make the RF big and clean enough. TG, FG and VCO are not needed to adjust. If necessary, adjust laser power VR on the iotical head to ensure the RF meets the requirement of 0.8/1.2Vp-p.

4: Lubrication mechanical parts and volume resistor are also necessary.

Good luck!

serge1996

Good folks at DIYaudio said that digital scope is a bad idea for getting an eye-pattern, that analogue scope should be used. I am still waiting for someone to send me the minimal specs for a digital scope for doing this but it seems that those in the know do not bother with such easy questions.
Meanwhile I found the option which is set as "default-ON" on my HP, it is called "Vectors ON/OFF" and once I set it to OFF the picture got recognizable as an eye-pattern.
I guess by DIP caps you meant SMD electrolytics? because they all gone bad

kaosun

serge1996 2015-11-19 21:44
Good folks at DIYaudio said that digital scope is a bad idea for getting an eye-pattern, that analog ...

Yep, all DIP caps should be replaced whether or not they're working. It doesn't have too many SMD caps, maybe 3? replacing all would be the best.  

Yep again, never use a digital oscilloscope to observe an eye pattern. I tried several but none suitable for eye pattern. Don't know too  much about that. I'm using a Tektronix 2246 4*100M analog oscilloscope which works perfect for me.  

kaosun

Your Vector on/off I though maybe something like trigger in Tektronix. Because the wave is dynamic, you have to set a trigger to capture the wave inside a window to display it. I might be wrong but pls refer to the operational manual.

serge1996

With vectors OFF it gives me an eye-pattern,... kinda... so I will continue using it for now... So far my success rate with D-90 restoration is three out of three fixed , thank you Master Gu for the inspiration!!! At some point I will have to sell some of them to recuperate the costs of this new hobby of mine. But first I am going to use my fine-scale-modelling skills to paint 'em in some unique colours, just for the heck of it
Modelling hobby is more rewarding, but this PCDP restoration is definitely more challenging, exactly what I need now.

kaosun