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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I recently reactivated my Beomaster 7000 which I purchased new in 1996 last Saturday after it had been in storage in original boxes (secured for shipping) for 10 years. When I first started the Beogram CD7000 it worked perfectly for about 2 hours. But now its started skipping on tracks 1-6. After track 6 it works fine. I tried several different CDs with same result. I would really appreciate any advice on how to fist this problem. Is it possible that the lens is dirty or perhaps the unit needs a recap? I do not have a service manual yet but would like to get some comments from anyone here who has experienced this problem. Thanks in advance.
Since the errors go together with the track numbers, you can also say, that they go together with the rotation speed of the disc. Therefore I blame the suspensions of the cd chassis. They are formed like little hooks that holds the frame im place.
Stu Mackiernan: I recently reactivated my Beomaster 7000 which I purchased new in 1996 last Saturday after it had been in storage in original boxes (secured for shipping) for 10 years. When I first started the Beogram CD7000 it worked perfectly for about 2 hours. But now its started skipping on tracks 1-6. After track 6 it works fine. I tried several different CDs with same result. I would really appreciate any advice on how to fist this problem. Is it possible that the lens is dirty or perhaps the unit needs a recap? I do not have a service manual yet but would like to get some comments from anyone here who has experienced this problem. Thanks in advance.
I would suspect the standard C2103 capacitor fault... Try searching for C2103 in the forums.. there are a lot of threads regarding this. Before doing anything, I would change at least this capacitor. Needs to be a blue philips(now called Vishay) capacitor.
Member Dillen kan supply you with a complete set for changing all caps in the servoboard.
But it is very easy to do, and just changing the C2103 will most likely fix the issue.
I have fixed may 6500/7000 cd's and all has come back to life with this new cap and a clean of the laser head.
/Weebyx
Thank you! Is it difficult to clean the laser head?
Correction. It is Beogram CD7000!
You could probably find a generic version of this for half the price. If it doesn't work, you're not out much.
Thank you! I have heard about these. I will try one first before opening up the unit.
Those CD lens cleaner discs with integrated brush is the best lens killer in this world.How anyone could ever come up with a thing like that is beyond me.My recommendation: DON'T use them!
Use cotton buds and IPA.Wipe wet, then wipe dry.(If IPA is left to airdry, it often leaves behind a thin cloud).
Martin
Thanks Martin. Good advice.
Everyone's entitled to their opinion. I've used them for years with no ill effect. On more than one occasion they cured a skipping CD player. And I know of at least one other forum member who's had great success with them. Here's a forum thread on the topic from 'What Hi*Fi?' Magazine in which a member opined: "Any attempt to clean the lens with cotton bud or similar is likely to result in scratches and possibly push the laser from proper alignment." And I know the user manual of the Beosound 9000 warns against it. Also, the vast majority of people don't know how to take apart a CD player to clean the lens with alcohol. Or don't want to risk it because it might invalidate the warranty. Are they supposed to just listen to it skip instead of attempting a simple fix? What about a car CD player?? It's not even possible to get at the laser lens without uninstalling it first.
I highly suspect that the 'correct' answer to this conundrum is not far from: IF you use a CD lens cleaner routinely (i.e. without specific cause) = once a week or more - you *might* scratch the lens after a year. Hopefully you'll concur
I understand where you are coming from. My issue is that when I turned it on for the first time in 10 years ( It had been stored in original box in transport lock down) it worked fine for a few hours. Then suddenly I get skipping on tracks 1-6 but works fine after track 6.
In view of Martin's comment, I'll retract what I said about buying a generic no-name brand of lens cleaner to save $. Go for a well known brand name - e.g.: Maxell, Allsop, Philips, Discwasher. Discwasher - perhaps the #1 brand known for keeping music media in good shape. Can you imagine them producing a product that will "kill" a CD laser lens? I can't...
Thanks Bob. Have you had experiences where half the tracks skip and half play perfectly? And this is independent of whatever CD I try. I would think that a dirty laser lens would cause problems on all tracks or none. I am wondering if its and electronic or mechanical issue and not a dirty laser lens.
That sounds like an odd problem but I'm not technical enough to provide any input. Someone suggested you replace a cap - I'd try that if you're capable. The service manual is available if you upgrade your membership. You might consider calling Space Age Electronics in Pompano, an authorized B&O repair center. I see you're in Florida. I have an excellent condition CD 7000 that I'll be selling. It's at my residence in Palm Beach, which is where I am at the moment. PM me if interested.
Getting back to CD lens cleaners, I found it interesting that Philips produced them. Who used to manufacture CD mechanisms for Bang & Olufsen? Philips. Would they sell a product that killed their own CD mechanisms? Doubt it. Seems more like an endorsement of CD lens cleaners to me.
The drive is held in four rubber supports. They dry out and break apart, causing the drive to rest onthe chassis when certain circumstances are given - like f.e. when the drives center of gravity shifts as the lens moves in and out.
Currently working on new parts...
Hello Martin,
Thank you. This may be the problem with my unit. I had to move it from the stack to access the Beomaster 7000 and the skipping started after the move even though I was careful handling the unit. Please let me know when you locate parts as I want to make all repairs (recap, belt) at the same time
Thanks Bob, I will call them. I want to bring my Beogram CD 7000 up to full operation with a recap belt change as I bought it new in '96 and it is pristine cosmetically. Other than the skipping on 1-6 tracks every thing else works. If you had a nice Beogram 7000 I might be interested as that would complete my system. Stu
Thank you. Would these need replacement or merely reattached? I haven't opened it up yet. Stu
Stu Mackiernan: If you had a nice Beogram 7000 I might be interested as that would complete my system.
I do. Works perfectly; front & inside mint; some scratches on top. Will probably eBay it since they're in high demand. Will send you a PM if/when I do.
Dillen: The drive is held in four rubber supports. They dry out and break apart, causing the drive to rest onthe chassis when certain circumstances are given - like f.e. when the drives center of gravity shifts as the lens moves in and out. Currently working on new parts... Martin
Good to know Martin ! These have been a very annoying issue on otherwise perfectly well-preserved and working machines.
Jacques
Is this just a 7000 / 6500 / 5500 issue or did they have the rubber supports on the CD50?
Cheers
Nigel
5500, 6500 and 7000 only.
The CD50 has a completely different drive type.
Good news! After being powered up for more than two days my CD 7000 now plays an entire CD perfectly. I tried different CDs and different tracks and they all played without any issues. This seems to confirm that the problem was not mechanical such as a dirty lens or damaged rubber mounts. My friend who is a EE tells me that old capacitors which have not been powered for a long time (in my case 10 years) can sometimes be "reformed" after being powered on for days. It's probably a good idea to recap the servo board before it fails again but at least I believe I know what the problem was now. Thank you Dillen and all others who commented here for their suggestions.
Hi all,
Sorry for reviving a zombie thread. Am facing the very same issue.
@Weebyx - You say that it has to be a blue Philips / Vishay capacitor. Let me be honest, my circuit knowledge is very limited, but since it's a cap in the power supply for the laser, should this really matter?.
All I could get my hands on this morning was a no brand 47uF/25v - and it certainly improved the skipping issue, but didn't fix it completely. (Also cleaned the laser with an alcoholic wet wipe and wiped dry afterwards).
It doesn't look like Dillen has the cap kit in his store anymore unfortunately :/ - Should I try to find a Philips / Vishay cap before I do anything else?
BR, and thanks, /Steffen
Flerbizky: Hi all, Sorry for reviving a zombie thread. Am facing the very same issue. @Weebyx - You say that it has to be a blue Philips / Vishay capacitor. Let me be honest, my circuit knowledge is very limited, but since it's a cap in the power supply for the laser, should this really matter?. All I could get my hands on this morning was a no brand 47uF/25v - and it certainly improved the skipping issue, but didn't fix it completely. (Also cleaned the laser with an alcoholic wet wipe and wiped dry afterwards). It doesn't look like Dillen has the cap kit in his store anymore unfortunately :/ - Should I try to find a Philips / Vishay cap before I do anything else? BR, and thanks, /Steffen
Yes, get the blue vishay capasitor before doing anything else.
You should also change the other non-smd caps, they should just be of good quality, no special needs there, and remember not to do any adjustments on the laser current to try and fix it, at least not until all cap(s) have been changed, and you can measure the current to be off.
I have seen a deck with a "Serviced by B&O" label on the PCB, that did not have the original vishay cap, and did not work. After changing to the correct type, it worked again.
It's the only component of this type on the board, all others are other brands and radial.It was chosen for a reason. Not because of its capacitance, but because of its filtering properties.When taken out, the old (bad) capacitor typically measures fine (or at least wihin reason), but its filtering charateristics have gone.
A blue Philips/BC axial it must be.
Thank you guys.
So the random selected 47uF that the local store had in, didn't completely fix the issue, neither a couple other random branded 33uF and 47uF, so went ahead and:
Did all the 4 supply caps as well as the one for the radial motor (2159, bipolar 470nF in the schematic, 1.5uF polar in reality - replaced with a bipolar 1.5uF Wima MKS 2-5 as suggested by Die_Bogener in an archived thread).
Also measured the laser current ("live", not in service mode) which should be 50mv +/-5mv. Gives me a constant 49mv, so even with my meter being crap, should still be somewhat ok'ish.
Did all the mechanical adjustments. Checked that the laser swings from end to end freely.
Yet. The issue persists - So Martin - do you happen to know where I can find a Philips/Vishay 33uF or 47uF (I think I'd prefer the 47uF from comments in the archived thread) in our vicinity (I'm almost in your neighborhood, have purchased a couple of your Penta kits earlier) or do I bite the bullet and buy them from Digikey as they have them in stock?.
Again, thanks hugely guys!/Steffen
On a completely different happy-hippo note- I rescued a CD X from a basement covered in ½ a cm of saw, concrete and plaster dust. Gave it a quick wipe down - haven't touched anything else yet, (didn't even wipe the laser), so far, it has played every CD I've thrown at it. Even came with the original external CD/Tape switch!
I have them.PM or email me.
Great find!
Either my soldering skills are getting really bad - or something else is wrong. I recorded the first attempt after replacing the no-name 47uF with the correct Philips one (Thank you HUGELY Martin!) - and much to my surprise, it didn't improve - actually, if anything, it made it a bit worse.
https://www.youtube.com/watch?v=fG6O9FYeuOw
Edit: My embedding skills are as poor as my soldering skills apparently
So I reverted to the no-name 47uF, same result, Martin was kind enough to sell me two of the Philips caps, so installed the other one (and crashed my phone while recording). -With this one, it seems better, but still not acceptable.
Any idea where to go next?.
[EDIT: 20180909]
Previous experience tells me (I'd long forgotten (last night at least) when I posted the above) that even boards that measure correctly when out, can change their behavior when mounted (pressure from screws etc.) - so even though I'd checked my soldering points before mounting the servo board, I double checked with the board in place this morning.
From the negative side of 2103 to the small jumper above (which should be ground) it reads 0.7Ω (told you my meter was crap ;) )From the positive side of 2103 to pin 17 on IC6101 - same as above, 0.7Ω.
And from the positive side again to the base of TR6108 (passing through a 100Ω res) gives me 101.4Ω...
Thank you!/Steffen
Hmmm. The plot thickens.
Since I'm very low on patience when I get my head stuck into something - I decided to try something else. So - looked in the danish equivalent of Craigslist (funny how that became the term) and found a Philips CD162 for the hefty sum of 50 DKK (around €6.5) - went and picked it up as the seller claimed it worked when it was put away 6-7 years ago when they moved)
Stuck in the offending CD (Singles Soundtrack) that's been giving me issues. Lo and behold. It plays the CD perfectly. No skipping, no ticks, it just plays (even at low volume on CX100s, it doesn't sound like the BG7000 that's for sure).
So. With the build quality of the unit, it takes all of 30 minutes to have the CDM-4/19 drive out. An hour later, the laser unit is mounted in the BG7000. I do all of the adjustments according to the manual. Focus voltage to 400mV +/- 40mV (39 measured on my crappy meter). 40mV on the laser in Test Mode 2.
All four test modes passes with flying color!
In the service manual under laser adjustment, it says: (In service position 2)
"Adjust 30R3106 until the voltage across 30R3102 is about 40mV". (This voltage varies when the disc is rotated). Leave service position 2 by switching off the mains briefly. Play track 1 on test disc 5. Adjust 30R3106 until the voltage across 30R3102 is 50mV +/- 5mV.
(This voltage varies when the disc is rotated).
Leave service position 2 by switching off the mains briefly.
Play track 1 on test disc 5.
Adjust 30R3106 until the voltage across 30R3102 is 50mV +/- 5mV.
The 40mV I can get spot on. BUT - if I keep the voltage around 35-38mV across 3102 when it's playing, it's almost ballpark - if I turn it up to 50mV as it says in the manual, there's lots of skipping noises.
Could it be something on the servo board. IC6101 having a really bad day?.
Thank you all for your invaluable help,/Confused in Copenhagen
[EDIT:] That's annoying!... Put the CD162 back together with the laser from the BG7000 and a minimum of screws to hold it together. I don't even think I tightened the 2.9mm bolts holding the laser in place come to think of it.
Power on. Annoying CD in the drive. Hit play. It just works. Haven't even touched focus or laser power pots.... I'm beginning to think our friends in Struer over complicated the drive part of the players more than they had to.....
Are all supply voltages correct and clean?Are you using the SONY YEDS-5 test CD or the 5/5A-set from Philips, that B&O once supplied?
I sincerely hope I didn't give anyone the impression that I have the slightest idea what I'm doing - because I mostly make it up as I go along :D
No. But at least I've been using the same CD when doing the measuring to keep those as equal as possible. Don't have access to neither of those CDs.
I will be checking the supply voltages next and post the result. I does look like it improves when it gets to up to temperature though. Have been through 4 old Alice in Chains discs this afternoon (bought in their hey-day, so old slightly worn discs) and it mostly behaves with only small clicks now and then
BR, and again, thank you!
You cannot use an ordinary audio CD for aligning the drive.They are far too different, they wobble, skew, runs off center etc.You can easily tell the difference from an ordinary audio CD to a real test-CD just by looking at the physical laser lens focus and radial balance movements.
The worst thing you've done so far is messing with the trimmers.DON'T ADJUST ANYTHING ON THAT SERVO BOARD - unless you know EXACTLY what you are doing!The problem with these drives is almost always capacitors - and occasionally excess ripple on the supply voltages.The lasers practically never die.- Unless messed with...It takes no more than 1/10th of a second of twice the recommended laser current to burn the laser - and the lasercurrent adjustment trimmer (unfortunately) allows for FAR MORE than that.In other words, it's NOT SAFE to touch that adjustment - the laser WILL go black very fast if the current is set too high.
In your case, I think it's safe to say, that one of the beams has gone weak.
Imagine having a car on auto-steering running on a white line on the road.Two sensors, one on each side of the car.If one sensor sees the line, the steering of the car is corrected to that side.When one sensor dies, the car may run and follow the line within reason for some distance, but it will eventually run of the road.
I might not have any idea what I'm doing, but that doesn't mean I can't read a manual ;)
Since I'd already swapped the 6 caps and that didn't fix the problem - I picked up the old Philips CD162 and swapped the laser. And in the manual, it does say, that when replacing (in my case, swapping for a used part), you have to set a baseline for offset and laser current. So I did as it says in the manual, and set laser current to 40mV and offset current to 400mV.
I would never touch anything without having understood the procedure, and since I now have the original laser safely stored (in the CD162) and HAD to make a baseline setting, I can't see how I could avoid touching the pots?.
Funny thing is - when I first measured the laser current after swapping the laser (it read 49 with the old one), it read 23mV - so of course the player would just go into standby as it had zero chance of reading anything - whatsoever. I also find it strange, that the best result with the least "artifacts", was with the current at around 42-43mV, and not the 50mV it says in the manual.
Anyway - as said, I will look at the stability of the supply when I dig the scope out of the closet.
Hmm. PSU seems fairly solid to me. Supply voltage measured at socket 33 of course:
(Top Left (-9.5V), Top Right (-6V), Bottom Left (5V), Bottom Right (9.5V))Full image: https://i.imgur.com/jl8R56O.jpg
Only thing I can see is that the -9.5V seems closer to -10V but I don't think that's going to cause a meltdown any time soon.
Measured a few pins on IC6101 (besides P2 and P28) that has power going to it. Nothing interesting whatsoever.