Help! Not seen this before.

I have just done the C2103 fix using a Dillen kit. All fine and CD mechanism now up and running, except......... it wont play past track 10!!

Known good CD mech plays fine when plugged into the same Beocenter 8500.

I don't know if the offending CD mech ever played past track 10 as I can't remember where it came from or what it came in and anyway, it wasn't working.

There was a feint smell of hot component when I first plugged the repaired mech in and asked it to play so I immediately stopped and investigated. Nothing obvious so asked it to play again and all seemed fine until track 11. At this point the mech stops with lights on up to track 10 and selecting 11 on k'board or remote gets track 1 playing.

Any body help with this???????

That's a new one.
Does the spindle motor stop ?
Is something blocking the laser blocks path ?

Martin

The CD stops spinning after track 10 and the laser block seems free and easy.

Is it consistent on stopping at track 10 regardless of the CD ?
Does it play the entire track 10 everytime ?

Martin

Only on those with more than 9 tracks and yes, it will play all of track 10.

I get the impression that this is not a mechanical problem and is more likely electronic or logic related?

I agree.
Hmm 

Martin

Thinking about this overnight (it's my age, y'know), the upper display only showed 10 tracks on an 11 track CD!

Will try again today with a more track CD and see what happens then.

More evidence to help with the diagnosis.

The repaired CDM4 does not re-set the number of tracks on the CD unless the Beocenter is unplugged from the mains!

ie If you simply change the CD with mains on, it retains the previous track info. For example if you replace a 10 track CD with an 11 track CD it still thinks that there are only 10 tracks on the new CD. Put in a 18 track CD and it still thinks there are only 10!

Unplug from the mains and put in an 18 track CD and it reads 18 tracks,replace with an 11 track CD and it still thinks that there are 18 tracks on the CD.

This does not happen with the working original CD mech which works normally.

Strange, what have I done??

Graham, how does the CD mech know you have changed the CD? Is it some sort of trigger from the door sliding open? If so could there be a bad joint in this part of the circuit? Never had a CD mech apart, so I may be talking complete rubbish. Just an idea.

Craig

I don't know the exact sequence Craig as I have never seen this problem before. I doubt it has anything to do with the door though but I'm willing to be proved wrong.

I certainly don't have a better idea at the moment!

I have 4 CD mechanisms to repair at the moment and it would be interesting to know what has happened here so I can avoid it in the future. The mechanisms were scrap anyway so I have not lost much except the cost of the components.

I have done many C2103 fixes in the past but this is a new one on me!!

So as I understand the mech is not originally from this Beocenter? It could be some slight incompatibility between it and the software on the controller board, as it seems pretty obvious that the BC doesn't know when the disc has been out and doesn't re-read the index tracks.

Seems it should know about it since the commands to open & close the door go through the same brains anyway, but...

Ok That's two of you telling me the same thing so there might be some truth in what you say. I'll try opening and closing the door.

Will do it this evening and report back.

Graham:

What exactly are you trying to do? Just have a number of CDM 4 off the shelf drop in spares?

Why are you swapping non B&O mechs into an 8500?

From experience the easiest thing to do is:

1) Replace the filter cap on the original mech. (which you have done).

2) If 1 doesn't work and you've determed that you have a weak laser, then you can transplant the entire radial arm from any CDM4 donor, keeping the old control B&O electronics.

If the original B&O mech control board is fried, you may then try to swap over individual components but the control board may not be fully compatible.

This is certainly true for CDM 12 IND found in the Overtures. They are not compatible with the standard Philips CDM 12s.

Derek

Hi Derek,

Long time no see. I hope you are well.

The 8500 is my test bed. It is usually to be found in my sun room connected to a pair of Beolab 5000 and mainly used by my wife for talking book tapes and CD's. Every now and then it gets transfered to my workroom as a test device.

During a clear out a couple of weeks ago it seemed that every box I emptied contained  a CDM4 mech which I had removed from various Beocenters over the years and which had been scrapped for a multitude of reasons which usually boiled down to "uneconomic to repair".

The CD mechs were very close to being consigned to the tip when something prompted me to repair them. Now some of these mechs had been fitted with replacement C2103 of the wrong type (not Philips Blue) and had not worked. I contacted Dillen and ordered a cap kit for one of the mechs which I have subsequently fitted.

I am testing the repaired mech on a flying lead hanging out of the back of my wife's 8500.

Go to start of story (unfortunately you will not pass go so there is no $200).

joeyboygolf:

Ok That's two of you telling me the same thing so there might be some truth in what you say. I'll try opening and closing the door.

Will do it this evening and report back.

OK you two.  Remember, nobody likes a "smart-ar*e" so stop smirking.

I opened and closed the door when I changed the CD and the bloody thing performs perfectly.

This is a good example of how easy it is to go off at a tangent and confuse your self.

Anyway, thanks Craig and Mika for suggesting the cure and you will excuse me for not posting a photo of my red face.

Thanks Guys.

Hi Graham!

I am well, thanks for asking.

Good stuff...glad it works.

Don't throw out CDM 4s! The radial arms are the best pick ups. They are becoming very rare.  Should be kept for parts.

Most of the time the B&O service center just swap and toss out the mechs because of the bad cap when the laser was perfectly fine. This has depleted all of the spares from B&O.

One day we'll regret not having enough of these around!

Btw.. you wouldn't happen to have spare BG 8002 MPU?

Derek

Derek

I'm afraid I don't have any BG8002 parts as I've never had one.

UsuallyI don't throw anything away until I run out of space and even then I usually regret it as I have a desparate need for just what I binned a month ago!

I have ordered the parts to repair the other three CDM4's that were saved from the skip!

joeyboygolf:

OK you two.  Remember, nobody likes a "smart-ar*e" so stop smirking.

I opened and closed the door when I changed the CD and the bloody thing performs perfectly.

This is a good example of how easy it is to go off at a tangent and confuse your self.

Anyway, thanks Craig and Mika for suggesting the cure and you will excuse me for not posting a photo of my red face.

Thanks Guys.

I'm not smirking at all! I never realized you can actually change the CD behind the back of the CPU, and I've had the mechs hanging out on cables as well!

auric:

Btw.. you wouldn't happen to have spare BG 8002 MPU?

Derek

 

Hi Derek,

              what part number is the CPU you are after? I may have one somewhere - can't make any promises though but I'll take a look when I know what I'm looking for.

Chris.

tournedos:

joeyboygolf:

OK you two.  Remember, nobody likes a "smart-ar*e" so stop smirking.

I opened and closed the door when I changed the CD and the bloody thing performs perfectly.

This is a good example of how easy it is to go off at a tangent and confuse your self.

Anyway, thanks Craig and Mika for suggesting the cure and you will excuse me for not posting a photo of my red face.

Thanks Guys.

I'm not smirking at all! I never realized you can actually change the CD behind the back of the CPU, and I've had the mechs hanging out on cables as well!

Here is what fooled it and me. I could change the CD without opening the door!

Glad you got it sorted in the end Graham. Have to admit it was a total stab in the dark, so to speak. Never had any of the 8XXX\9XXX range apart. Nearest I have been was removing something at the rear of an 8000 so I could fit the lift up flap over the conections back on. Sometimes though you can miss the obvious. When you do, you start to think of all manner of wierd and wonderful causes for you faults. Done in many times in my old job. Walked away had a fig and a cuppa. Then started with the basics again. When you do find out what is wrong it's a real Homer Simpson moment. DOH!!!

Craig

Craig:

it's a real Homer Simpson moment. DOH!!! 

Craig

I think we've all had a few of those Craig............

Glad you got it sorted Graham.

Chris.