ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I know this has been discussed in other threads but i don't really recognize the symptoms as described by others.
I bought this unit for a reasonable price on an auction. I was informed that it had been dropped on the floor and no function guarantee was given. Anyhow i thought I'd give it a try. After receiving the unit I could see some external damage. One door was damaged and also the plastic case at a bottom corner. Tested the unit to find that doors where functioning but where not opening or closing fully. Radio was functioning flawless but the CD did't react. Removed the doors and back cover, doing that I found the most of the screws where missing. Open i found among other things the CD servo PCB loose and with the ribbon cables disconnected.
Reattached cables and reassembled CD unit. Now when testing the CD it spins for 1 second then stops. Don't read CD at all.
Putting the unit in test mode it looks as the laser is working, focus motor is working. laser motor working but when trying to start CD motor nothing happens.
CD unit is the newer CDM12 from 1999.
What is the most likely fault? The SMD caps on the servo board? If yes, all of them or any special one?.
Damaged door
Removing doors
Straighten snap in bracket
Corner damaged
PCB inside damaged and "repaired"
Servo board was unmounted, completely loose
Ribbon cables unattached
Bad caps?
Reassembled for test
//Bo.A long list...
Bos00:PCB inside damaged and "repaired"
This is usually a sign of a repairer that doesn't know a bit about what he is doing - why jumper the broken tracks back in? The 3 cm of copper track in the loose corner doesn't have any magic qualities, just skip it entirely with a single jumper wire... (and relocate the single component / jumper wire that actually was connected on it)
I wouldn't worry about any caps or other component failures at this point, it is obvious that you will find a lot of connection problems to solve first.
--mika
Most common problem and solution. Replace the laser.
Costs about 10-15 euro max.
Done several with the same symptom, replaced the laser and worked again. You can find them easily at ebay.
Ordered a few lasers CDM12 last week. Think I'm gonna place a thread how to replace them if anyone is interested!
Brengen & Ophalen
A laser diode will usually not die from being dropped on the floor.In fact, the laser diode is usually one of the most robust components in the whole machine, both physically andelectronically, and it's very rare to see a burned out laser diode. It's almost always something else causing it not to work.I'm not saying that it cannot happen, just that it's rare to see.I've replaced only two or three in my time, at least one of them was due to mechanical abuse from a "repairer" tryingto make the laser focus by grabbing and forcing it with pliers...
That PCB corner; I'm afraid I must agree with Mika. It does seem to hold a single component or something elseon the other side, but a repair involving a fresh set of leads across the entire broken area would have beena much nicer repair. What you've done may work now but vibrations etc. will eventually cause it to breakand develop intermittent problems, no doubt.If the corner has a supporting point, glue it back onto the rest using araldite and then pull new leads across the wholebroken area. Three leads in this case, it seems, unless more is broken.If it doesn't hold a supporting point, throw the lose corner away.Still, I cannot help thinking that lots of components will have become hurt in some way or another from the drop.Generally, physical blows like this is a no-go for almost any PCB.ICs can end up with internal "scars" to the junctions connecting the pins with the dye chip, something thatwill show up sooner or later.SMD populated boards like this are worse than conventional ones. You will never find the IC with one pin brokenaway 1/1000mm from its solder pad...
Laser diodes are easy to replace. Getting the adjustments right afterwards can be a completely different matter,particularly after a 30+G impact like this.Still, as Mika suggested, I would concentrate elsewhere first; Power supply voltages, control signals etc.Check the cats eye pattern, it will tell you everything!
I do like a challenge myself, long time members will know this and I have a huge respect for people who are willingto go the extra mile but, personally, I think, I would steer clear of a unit like this.
Martin
Dillen: A laser diode will usually not die from being dropped on the floor.
A laser diode will usually not die from being dropped on the floor.
It isn't said that the system worked properly before it dropped.
I repaired a BS9000 mk1 from '99 with a CDM 12.6. This system also dropped on the floor. It had some serious scratches on the alu panel and a broken glass window. After repairing that, and some capacitors in the powersupply, and a thorough cleaning of the complete system, the system didn't play cd's either.
After replacing the pickup element, the BS did play cd's again. It is just a matter of how many hours the system has played cd's. A worn out laser is more likely with aging systems.
Agreed that you should check everything else before replacing lasers. But that's something I assume Bos00 already has done..
If the laser diode is bad, by all means replace and readjust.It's just not the first thing, I would suspect in a situation like this.But, hey, we don't know if the machine was dropped by accident or tossed on purpose..
Beobuddy:After replacing the pickup element, the BS did play cd's again. It is just a matter of how many hours the system has played cd's. A worn out laser is more likely with aging systems.
There seems to be some misunderstanding - I believe the repairs I first commented on were something Bos00 found inside the machine, not ones he has made himself
Quite typical though... I'm still sore about the Beocenter 8000 I once bought with a "non-functional CD". The seller told me that nobody had tried to repair it (and so I assumed it to be the simple cap replacement). When I opened it up I found a number of detached ribbon cables, as well as some replaced caps on the servo board that weren't even soldered in(!) and the nicest suprise of all, a dead laser.
Oh, if that's the case I misunderstood it. Sorry, I'm getting old. I've mainly dealt with the older CD players, CD50, CD X etc. anyways. Their technology and playing hoursis of no match to this one, I suppose and my experience in matters B&O is limited at best.I will pull out here and leave room for the more experienced tech'ies.
Dillen:Their technology and playing hoursis of no match to this one,
Oh, no worries - every now and then, I still feel the tobacco smell when I open the doors of the BC8000, about four years after I bought it. It was probably owned by some 19th century tobacco dealer so has seen quite a few CDs. Also, I believe the laser had been killed by the repair attempts...
Thanks everybody,
As said, I picked up the unit in this condition. It is not clear whether the CD worked before it was dropped to the floor. What is clear is that somebody, unprofessional, tried to repair it and gave up.
Ill do this.
1-As suggested make a better repair of the PCB in the damaged corner (However I've already secured and measured all connections in that area)
2- Check power supply,. Done, seem OK, 5V & 9V to the servo board id OK.
3- Change caps. Done so with some caps i had laying around, Didn't help. Ordered new ones.
4- If above don't help, change the laser. However, if bringing the unit into test-mode, you can actually see the red light from the laser, indicating it's working. I don't know if it can be working but maybe not strong enough. On the CDM 12 the is no adjustment for laser current or focus so there not much you can do apart from changing the whole unit.
One can also suspect that maybe the previous attempt to repair caused some faults to the servo board. The circuits are very sensitive to static electricity.
I'll keep you posted.
I had Techics with CDM12, spins, didnt play, reason was spindle motor, guess didnt spin fast enough.
Now I have one CDM12 from BC9300, same as yours, it dont spin at all, no voltage to motor, dont know why...
blah-blah and photographs as needed
Orava: I had Techics with CDM12, spins, didnt play, reason was spindle motor, guess didnt spin fast enough. Now I have one CDM12 from BC9300, same as yours, it dont spin at all, no voltage to motor, dont know why...
Mine spins approx 3 revolutions before it stops. Seems to get up into full speed quickly.
Bos00: Mine spins approx 3 revolutions before it stops. Seems to get up into full speed quickly.
So, did mine. It's same symptom as CD50's motors in need of cleaning. But your motor might be ok as well, I couldn't tell by looking. Maybe it could be measured somehow.
Leslie: Ordered a few lasers CDM12 last week. Think I'm gonna place a thread how to replace them if anyone is interested!
@Leslie,
I'm very much interested.
Where did you order them from? Please post photos when available.
Please wait, still waiting for them. As soon as I have them I will do the exchange and will post pictures!
My 2300 CD spins 2 or 3 seconds and then stopped, can't read any CD, could it be fixed with your laser module?
Beocom 6000, Beocom 1, Beocom 5, Beolab 4000, Beocenter 2300, Beo4, Earset 2, Earset 3i
The Beocenter 2300 came with different CD mechanisms over the years.
Early models came with CDM 4 which have a very reliable laser. In this case it's most likely a capacitor problem (well described in other threads)
Later models came with CDM12 industrial and later CDpro. In these cases the laser is most likely the problems. Lasers can be bought on e-bay but you have to find out which CD mechanism you have.
Hi,
the CDM-4 Unit moves the laser in an arc whereas the later units move linear.
The CDM-4 very often suffers from the 'C2103' problem. In the Beocenter 2300 / 2500 it's the C100 on the 'CD SERVO Motor System AND DISC DETECTOR' Board 97. The Capacitor is a 47µF connected between Pin 17 of TDA 8808T and Ground (Focus Servo).
Ralph-Marcus
Hi Leslie,
it would be great if you could share your experience on the CDM12 change. I too experience a CD down issue with my B2300.
cheers.
Could take a while, finished all my BC2300's. I'm waiting for the next one :-).
Where you from? Maybe I could have a look at it if you live in Holland?
Thanks for the reply. I am from Malaysia. I plan to DIY the CDM. Bought the optical pick-up from Liberty USA.
I hopeful to learn some tips from you and fellow Beos here about my BO2300.
thanks.
Malaysia? Been in Port Dickson for my employer. Beautifull country...
Anyway, take the necessary ESD precautions. Lasers are highly sensitive for electrostatics. Before you know it will blow :-)
Hi ... great.. I am about a couple of hours away from PD. Good to know the place gives you some good memories ( i hope).
As for the Beo, I audiotech advised me against it. Anyway, will wait for the item to arrive and let the expert do it.
Anyway, I wil continue to scour the internets for info.
Maybe this could help just to give you an idea how laser replacement works?
hi thanks for the tip on changing the optical len. However, it appears that my unit' s fault is not that straight forward anymore (according to my independent hifi technician). The control board is faulty?
Well, looks like its to the B&O service and repair centre then.
In 96.75% of the cases I have encountered when CD's stop to spin or will not read (in linear tracking lasers - the later models - mid nineties onwards, it is ALWAYS seems the laser diode). I have swapped many. it is an easy job once you have done it a couple of times. The earlier lasers in earlier equipment (that move in an arc rarely fail) it's generally something on the board!! My BC9500 had spindle failure. There are clips on youtube about disassembly of an upright beosound, you just have to work out how to change the laser diode yourself, once the CD mech is out. Not too hard, with some patience.
Chaka could you tell me where that smd diode of the laser is located on the beosound 2300 you were referring to?
greetings Steven
you have to change the complete 'Philips CDM12.4 laser unit CD Optical pick up'.
If on the flex cable is printed 'EF-20 3067' it should work flawlessly in a CDM 12 Industrial drive.
Thanks! Will do that.
never knew the 12.4 would do too.
greetings from the netherlands
steven