The DIY Discman Repair Thread - Page 3

So far so dinky doodle doo
Can't find my >75mins long CD's now

D-777 skipping problem(long play CD's) 'GONE'

Cleaned the worm gear and relubricate it with Tamiya Ceramic Grease (for remote controlled scale cars). And shoved in a long play CD twice and job done.
Thank you Duncan for the help/tips! Much appreciated.

D35(0) service manual

If anybody's interested, I've scanned the D-350 service manual:
http://home.no/rettweiler/discmen/D35_sm.zip
Will take it off that server Monday (07-28) morning.

Sony D-555 restoration

Hello,

Purchased a D-555 back in 1990. It was/is a great portable CD player. Soundwise, probably the best ever made. Early DSP for 5-band EQ, "Surround", Bass Boost, and Dynamic range compression. Incredibly clear, detailed sound without being harsh. Bass is not lacking. Dual Burr Brown 16-bit D/A converters. Peak hold VU meters. Remote capable. No ESP but who cares? The headphone outputs are hiss free. This player was built for sound.

Some years ago the player began to behave erratically: one channel almost out and the LED illumination was not very good. I set the D-555 aside and figured it for the scrap heap. A pretty sad day as I really liked this player.

Over those years some electronic repair skills were obtained. Two weeks ago it was decided to try and rescue this old friend.

Condition: Powered up! Could barely track a disk but it did OK. One channel was still almost out and the LED illumination was still uneven. The recharageable NiCd BP2-EX battery was dead and no good.

Diagnosis: What seemed like a lost cause all those years ago turned out to be a fairly easy fix: bad 6.3v 100uf SMD electrolytic capacitors. All three in the unit were bad. One was in the power supply, two were used for coupling the headphone to the headphone amp. One of the headphone output coupling caps measured virtually nothing and was leaking electrolyte. The other two measured high and were leaking electrolyte as well. They failed the ESR test.

Repair: The D-555 was disassembled. Lots of screws and be careful with the flexible ribbon boards but it is fairly easy to disassemble if one is organized. The area of the leakage was cleaned with a cotton swap lightly dipped in 91% isopropyl alcohol. New Nichicon high-temp, low ESR, SMD electrolytics were ordered from Mouser and installed. (Note: SMD (surface mount device) is somewhat tricky to the non-skilled but can be done with a *very* fine tipped soldering iron at low temperature). The unit was powred up. BINGO! Even LED illumination, audio in both channels. Adjusted the focus/tracking by ear (Note: listen for mechanism noise as it tracks a CD -- too little noise and the player skips easily, too much noise and the player is "working" too hard. The best spot is to have the mechanism noise just a bit above minimum). Obtained a copy of a service manual from a local source and checked/adjusted battery recharge voltages. Obtained a new BP2-EX NiCd battery from Sony (pricey, but still available).

Results: Working like new! No ESP so the player will skip if bumped hard but otherwise it loads discs fine, tracks well and has that wonderful unmatched D-555 sound. A bonus is the DM1K remote control still worked perfectly after not having been used for years.

Headphones used: Sony MDR-V6 had been used originally and work well. For the recent restoration I have been using the Radio Shack "Titanium" (Koss "Titanium" Pro) and it seems to be a good match for the player's capabilities. The highs are distortion free and the "Titanium" can handle the enormous, deep bass the D-555 player is capable of delivering.

My friend is back and has been performing flawlessly. After 13 years the Sony D-555 CD player still sets the sonic standard for portables.

Best regards,

Paul

Hello Duncan,

Glad to provide the info. I hope it helps someone revive a problematic D-555. All three of the same type SMD capacitor (100uf 6.3v) had gone bad. Maybe it was a bad production run or these SMD types had not matured enough at the time of manufacture. I would suggest that any D-555 owner skilled enough to replace SMD aluminum electrolytic types to investigate doing so. Especially if the D555 starts to sound thin. Leakage of electrolyte from these caps could ultimately damage the circuit board.

In reading through some of the D-555 posts last night (including your reviews of the classic Sony units -- great work, by the way) you mentioned a difference in sound between the headphone and line out. Maybe the following from the schematic and my restoration will help shed some light:

Line out:
The Burr Brown PCM66P D/A converters are coupled to the line out amplification stage by 2.2uf Tantalum capacitors. The line out utilizes a single NJM2107F opamp per channel. Coupling to the outside world is done via a tantalum 4.7uf capacitor through a 2.2uh inductor (removes ultrasonics but the phase relationships at audio frequencies should be relatively untouched).

Headphone out:
The headphone stage is separate. It taps off the 2.2uf tantalum at the Burr Brown output and then goes to a NJM2107F opamp, just like the line out (total of four NJM2107F in this player). The output of this opamp then goes to the CXA1263W headphone amp coupled by another 2.2uf tantalum. The headphones are coupled by a 100uf 6.3v (the bad types indicated earlier) through a 2.2uh inductor as well.

My previous restoration notes are a bit simpler than what actually happened (didn't want too many side notes). As I understand it, the best coupling for 32ohm headphones requires a 220 uf capacitor or larger. I experimented a bit with very expensive Kemet 470uf 6v polymer SMD tantalum types (low ESR), Panasonic 470uf 6.3v FC (low ESR 105deg) leaded type as well as the Nichicon 220uf 16v UD (low ESR 105deg) SMD type.

Results: Kemet -- the capacitors fit perfectly but the sound was muddy and the highs muffled. Completely unsatisfactory. Too bad, these capacitors cost a lot of money.

Panasonic -- great sound. One problem - the capacitors were too big. Could not seat the printed circuit board properly despite efforts to do so. Ultimately unacceptable because of the size problem.

Nichicon -- great sound, perfect fit. No doubt the quality of these capacitors exceed the originals.
I'm sticking with the Nichicons.

Space is very limited inside these little Discman boxes so the ability to provide audiophile-type enhancement is virtually nil. Still, improvement of the headphone output coupling caps has some limited possibilities.

Best regards,

Paul

I recently had a similar issue with a D-9, one channel was 1/10th the volume of the other. Armed with a scope and the schematic, I tracked it down as well to a SMD electrolytic coupling cap between two stages. Curiously, this player uses a SMD electrolytic for one channel, but a through hole type for the other. (one of the reasons you don't stand much of a chance without a service manual, keeping track of the signal path is a nightmare - the signal enters and leaves the same chip several times, goes to another chip, comes back, changes PCB sides, goes to one single cap on the other end of the board, returns...)

Hello Peter and all,

That is really strange. Imbalances such as that in stereo audio circuitry bother me.

For the record, according to the D-555 schematic, the three capacitors needing replacement are:

Audio: C211, C111
Power supply: C401

SMD type 100ufd @ 6.3 volts. Standard size for rating: 6.3mm width 5.7mm height.

For the audio upgrade I used SMD type 220ufd @ 16v. Size 6.3mm width 7.7mm height.

Best regards,

Paul

I just got a D-555, but during startup and changing tracks, i can hear the mechanism move. Also, i can hear the motor during pauses and at low volumes. What'w wrong with it?

My D-350 did that also but would eventually tell me that it had no disc in it. Adjusting the focus bias helped in that instance.

As for my D-350, after all of the adjustments to the 501-505 pots (minus the 504), there was still a lot of static. Does anyone know of the cause for this and how to fix it?

Also, it only seems to work in the vertical position and in the horizontal position, spindle wobble would keep the laser from reading the cd correctly. Has anyone changed a spindle motor before or know of a way to fix this without changing the motor?

Which pot is the focus pot in the 555?

Man, that sucks, sorry to hear that.
I'm afraid I know too little about the innards of a 311 to help with a remote diagnosis...
What does the lineout say?