I am always very wary of replacing a laser immediately, because there is always the real probability that the Servo PCB is faulty, and a new laser will simply burn in short order.

So, Philips (B&O uses Philips Lasers) Service manual has a procedure to test the Servo PCB laser circuit BEFORE installing a new laser, using 2 resistors, a Green LED and an On/Off switch.

The laser adjustments were still not improving, and I checked that the laser is actually working - the RED light is there, quite clear.

So, I am not yet convinced that the laser is shot.

I examined the Focus lens, and noticed that it is very stiff, and cannot move up and down.

So I disassembled it to clean it.

Now, when I push the lens manually, it now moves freely up and down, but when switching on the machine, the lens does NOT move up or down, as it would search for a focus point on the CD.

The Focus Coil measures 22 Ohms, within the Service Manual spec.

Because the Focus Lens was stuck, I suspect the TCA0372 OpAmp, which controls the Focus circuit, and am now troubleshooting that.

I can see on your picture, that you have not used the correct Philips/Vishay C2103 capasitor ?

I actually thought that you might never get a servo PCB functioning perfectly without using this specific C2103 ? The many 35/45/65/7000 cd's I have seen not working, always first came back to life perfectly after using the correct capasitor ?

Is there any reason as to why you are not using the correct one ?

/Weebyx

I have serviced many of these Servo PCB's, and they all work just fine with Panasonic FC, FM, or Nichicon HE or PW 105°C Low-ESR capacitors.

I'm sure that any other equivalent reliable capacitor would work just fine, as well.

Having scoped that circuit (among many others), the waveform confirms there is absolutely no "magic" in the blue Philips capacitors, and there is NO technical justification to NOT use any other high-quality capacitor instead. 

Menahem Yachad wrote:

I'm sure that any other equivalent reliable capacitor would work just fine, as well.

My experience from doing hundreds of these drives, is that nothing but a Philips/BC capacitor can be guaranteed to work.
And I have tried A LOT of different capacitors, mainly because I at some point had difficulty finding old stock Philips caps.
I cannot see any difference on the scope either, but there definitely IS a difference in functionality.

It's the only axial capacitor on the board, all others are radial (and not even Philips brands in most machines).
That blue axial was chosen for a reason.

The technical justification lies in the capacitors filtering properties. I have a feeling that the keyword is "ringing", but with no scope images to
show it, I cannot be sure.
Its capacitance is less important. You could even fit a 47uF.
The bad original C2103 capacitors will usually still measure fine as capacitors and carry on wonderfully if tested in other circuits.
It's like their filtering properties "wear out".

At some point I found a cheap chinese brand capacitor type that also seemed to work.
It turned out to only last for about 50-100 playing hours for each replacement. It "wore out" even faster - but still worked fine as a capacitor
in other circuits.

I would also replace C2103 with a blue Philips/BC as the first thing if on my bench.

Martin

Exactly right Martin. If that blue Philips is not there for a good reason, why use it?

When Anthony Garza originally told me about the problem, many years ago, he insisted that I replaced the c2103 with a Blue Philips. He knew something even then.

Gentlemen

I'm glad this subject has been opened.

Firstly, if there is empirical proof that the Blue Philips cap is better, I will be the first in line to start using them again.

However, until now, all I have seen is "He said", and "They said".

That doesn't constitute engineering proof.

For the history of WHY Philips used these capacitors, we need to look at the BIGGER picture of the corporate alignment of the European companies in the 1970's and 1980's, which was an extremely turbulent time in the Electronics industry, with the Japanese making destructive inroads into the markets controlled by Philips, Grundig and others.

I worked for Grundig right at that time, so I remember it extremely well, shutting down the productions lines in Germany, and moving them to Portugal.

Does anyone ever remember seeing Radial Philips capacitors in any electronic equipment of that era?

Nope.

Why not Philips Radial caps in B&O (B&O was partly owned by Philips for some time)?

Philips made ONLY Axial capacitors, and they made absolutely CERTAIN to use their OWN in-house Components (where possible) on their PCB's. That's why (failing any technically-proficient position) we see that Blue capacitor in Position C2103. 

Has anyone ever taken a good look inside other high-quality European equipment (besides B&O), such as Studer?

What's inside are Roederstein Radial caps. You won't find a single Philips capacitor inside. Competition issues, during a VERY tough time.

BTW, B&O used Philips Axial caps, and Roederstein Radial caps.

So Philips had to make a purely commercial decision who to use for Radial caps (during a time when money was in VERY tight supply).

I'm sure they looked at Roederstein, but they made the (excellent, in hindsight) decision to go with Nichicon.

If any of you have worked on any Studer equipment (as I have), you already know with absolute certainty that every one of the hundreds of installed Roderstein caps is beyond shot. 

And if we look at Philips' CDM PCB's - the same ones used in B&O's players - we see that ALL the Nichicon caps are just fine, while the Blue Philips caps are completely shot.

Now, before throwing out more "But He said"s, permit me to ask ONE simple question.

Is there anyone out here, who has done EXACTLY the following test procedure to PROVE, once and for all, that the Blue Philips cap is superior for position C2103?

1. Installed a new Blue Philips cap of 33uF or 47uF onto the Philips-manufactured Servo PCB, and had the laser return to normal operation.

THEN

2. Removed the Blue Philips cap, and installed a high-quality 33uF or 47uF Nichicon (Philips' primary outside choice) in the same position, and then witnessed a complete failure to work?

If there IS somebody who has that empirical proof, please stand forward.

If there is nobody who has that proof, I cannot accept conjecture or "He said", as a pertinent argument.

Engineering is based on pure facts, not conjecture or opinions.

At the end of this troubleshooting, I will do EXACTLY that test, and let you all know how it goes.

And if I am proved wrong for having used a Nichicon cap INSTEAD of a Philips cap, I will be the first to admit it.

Until then, kindly let's stick to facts.

Menahem

Hi,

I use BC axial caps as well. Some retailers still stock them near me so it’s a no-brainer.

I just admit that other, possibly better caps, don’t work well here, with CDM 2/4 transports becoming noisy, erratic, picky.

Whatever the reason is, the BC works every time, so let’s be humble and accept that. 

Well I am and I do!

Menahem Yachad wrote:

Is there anyone out here, who has done EXACTLY the following test procedure to PROVE, once and for all, that the Blue Philips cap is superior for position C2103?

 

1. Installed a new Blue Philips cap of 33uF or 47uF onto the Philips-manufactured Servo PCB, and had the laser return to normal operation.

THEN

2. Removed the Blue Philips cap, and installed a high-quality 33uF or 47uF Nichicon (Philips' primary outside choice) in the same position, and then witnessed a complete failure to work?

 

If there IS somebody who has that empirical proof, please stand forward.

Here.

Not sure if that's enough to consider it imperical proof, though, but as mentioned above, the capacitors seem to "wear out", - some sooner, some later.
Most capacitors, even ones of the "popular" and/or "trendy" brands cannot be guaranteed to work. And even if one might seem to work, it won't be for long.
Fit a blue axial Philips/BC (and it could easily be an old stock Philips from the late 1980s, as long as it's unused!) and the drive will play on for
at least the next decade.
That's my experience.
That's the facts as I experience it and that's what I have to share.

Philips did make radial caps in the 1980s.
These - or some just like them - were around back when I built a lot of electronic home constructions in the mid-late 1980s: