Technics SL-PS700 CD Player servo fault. - UK Vintage Radio Repair and Restoration Discussion Forum

samjmann · 29th Apr 2025, 8:39 am

This player is now 30 years old. I still think of CD's as newish!
It would focus, but the disc speed was slow and of course there was no TOC read either.

This was designed as a so called 2nd generation player. Linear sled motor and 'Digital' servo also. Digital was also shown on the VFD display.

The servo and RF pre-amp are all on a small pcb on the underside of the laser/loader block. Access was near impossible for testing. After removing the whole block I gently warmed the small servo board and quickly reassembled. The player then read the TOC and played for 2mins, then failed to read again. The board had 10+ sub miniature through the hole electrolytics.

Separating the flat foil of the laser head from the connector was near impossible. If this tears, the unit is instant scrap!
Because of this I decided to re-cap the servo board in one go.
I hate this approach, but the propensity of damage to the laser ribbon escalated with each removal.

RS stocked direct replacements of all the small electrolytics.
The photo shows the finished board.There were 3 non-polarised electrolytics that I didn't swop. They did test perfect however.

On reassembly it worked first go. Near instant TOC read. Track selection was extremely fast. I've one CD that's got a 79min playing time. (Longer than Red Book spec?). Again tracking and playability was 100%.

As mentioned earlier, a block change of parts isn't without risks and can easily lead you down a rabbit hole. However there are times when you don't have many options!!

SJM.

Nickthedentist · 29th Apr 2025, 8:41 am

Fantastic result, completely agree with your logic!

Station X · 27th Jul 2025, 8:37 am

One post moved to a new thread here:-

https://www.vintage-radio.net/forum/showthread.php?t=221214

29th Apr 2025, 8:39 am	#1
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, Nottighamshire, UK. Posts: 807	Technics SL-PS700 CD Player servo fault. This player is now 30 years old. I still think of CD's as newish! It would focus, but the disc speed was slow and of course there was no TOC read either. This was designed as a so called 2nd generation player. Linear sled motor and 'Digital' servo also. Digital was also shown on the VFD display. The servo and RF pre-amp are all on a small pcb on the underside of the laser/loader block. Access was near impossible for testing. After removing the whole block I gently warmed the small servo board and quickly reassembled. The player then read the TOC and played for 2mins, then failed to read again. The board had 10+ sub miniature through the hole electrolytics. Separating the flat foil of the laser head from the connector was near impossible. If this tears, the unit is instant scrap! Because of this I decided to re-cap the servo board in one go. I hate this approach, but the propensity of damage to the laser ribbon escalated with each removal. RS stocked direct replacements of all the small electrolytics. The photo shows the finished board.There were 3 non-polarised electrolytics that I didn't swop. They did test perfect however. On reassembly it worked first go. Near instant TOC read. Track selection was extremely fast. I've one CD that's got a 79min playing time. (Longer than Red Book spec?). Again tracking and playability was 100%. As mentioned earlier, a block change of parts isn't without risks and can easily lead you down a rabbit hole. However there are times when you don't have many options!! SJM. Attached Thumbnails __________________ It's never been right since we've had it...

29th Apr 2025, 8:41 am	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 19,112	Re: Technics SL-PS700 CD Player servo fault. Fantastic result, completely agree with your logic!

27th Jul 2025, 8:37 am	#3
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 22,803	Re: Technics SL-PS700 CD Player servo fault. One post moved to a new thread here:- https://www.vintage-radio.net/forum/showthread.php?t=221214 __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.