The Workbench

Re: Beocenter 9300 cd fault

mrjones — Mon, 13 Jun 2011 06:57:22 GMT

I tried that this morning no improvement. The head is linear, and the guide rail has been recently removed and replaced as part of the renewal of the laser head assembly.

The disc now reliably spins for a couple of seconds and stops, and has not read the toc since it was recapped. I am trying to deduce the stage it is reaching before failing and it seems that :-

It establishes a disc is present

corrects focus height

spins disc and attempts to gain tracking.

this is the point where it fails, so it could be :-

failure in tracking logic or insufficient spin speed to successfully track.

I'm now looking for a motor!

Re: Beocenter 9300 cd fault

Die_Bogener — Mon, 13 Jun 2011 02:51:39 GMT

Yes. There is a plastic/bronce bushing guide inside the head. Without some oil/grease it becomes sticky. Clean it first with some alcohol, then use a fine oil. I use a oil for lock cylinders of doors.

Re: Beocenter 9300 cd fault

mrjones — Sun, 12 Jun 2011 17:37:12 GMT

I'll give that a go tomorrow. I have replaced the laser so that bar is definitely clean, do you think it could be lacking oil/grease?

Re: Beocenter 9300 cd fault

Die_Bogener — Sun, 12 Jun 2011 14:30:16 GMT

Try to clean the round steel guides of the laser head. Use a very fine oil and remove all dust/dirt.

Re: Beocenter 9300 cd fault

mrjones — Sun, 12 Jun 2011 14:10:21 GMT

I managed to recap the servo board, which I found easy thanks to the tip on removing the original smd caps (twist them off). Sadly this did not fix the problem and I now suspect the motor (apparently these were prone to failure). Anyone have a european or UK source for these?

Re: Beocenter 9300 cd fault

mrjones — Wed, 08 Jun 2011 14:43:16 GMT

Thanks for that. I will use 105 degree and I'm not planning on SMD caps. Incidentally I can't see any pic with your post, would be very interested in seeing the finished result.

Do you think I'm on the right track as far as solving the problem is concerned, or could I have other problem areas to look at?

Re: Beocenter 9300 cd fault

yachadm — Wed, 08 Jun 2011 13:18:37 GMT

Here's one which I did, with regular leaded capacitors instead of SMD replacements.

I use Panasonic EB, Nichicon HE, and the blue one is a Vishay BC 150RMI.

All are 105 degree caps for extra-long life, and you can use any or all of these on the PCB for guaranteed operation.

If you insist on using SMD caps as replacements, the Panasonic FK are quite suitable.

Menahem

Re: Beocenter 9300 cd fault

Die_Bogener — Wed, 08 Jun 2011 10:35:52 GMT

Just replace these 6 SMD caps, that's all. Dont worry about the tantalum caps, they will have no problem.

Martin

Re: Beocenter 9300 cd fault

mrjones — Wed, 08 Jun 2011 07:35:17 GMT

Heres the chip one.

Re: Beocenter 9300 cd fault

mrjones — Wed, 08 Jun 2011 07:32:12 GMT

I have two more pics which I think show damage on the board which may be relevant, one is what looks like damage next to a cap, and on the other side of the board the TDA7073AT on the right is loosing the print, is this damage from heat?

Re: Beocenter 9300 cd fault

mrjones — Wed, 08 Jun 2011 07:24:11 GMT

I am trying to repair a 9300 linear cd, withe same board pictured in this thread. I have changed the laser assembly and am having some success but the current behaviour is a bit puzzling. I have been able to play a disc but only twice, the rest of the time the laser reads the disc for a couple of seconds and then stops. Once the disc is playing I have been able to skip through tracks, but once stopped it goes back to the erratic behaviour and is unable to read the toc.

I am about to change the 6 large caps on the servo board, should I consider changing the tantalum caps on the other side? What considerations should I have when choosing replacements as far as quality is concerned?

Re: Beocenter 9300 cd fault

pera123 — Wed, 20 Apr 2011 08:59:56 GMT

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normaali taulukko"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

Hi,

I am glad to answer to my self. I got this fixed the laser was bad. New laser did the job. I toke the laser from CDM 12.4, very cheap and pretty easy fix.

Now to fix Beolink 1000.

Cheers,

Pete (Finland)

Re: Beocenter 9300 cd fault

pera123 — Thu, 07 Apr 2011 01:49:38 GMT

Clive where you apply to fix this problem?

I have exactly the same problem in my Century. And it has the exactly same CD PCB.

I have changed all the SMD electrolytic caps on it, with regular feed through caps, but it didn’t help. On my board also the two biggest SMD caps (330uf and 100uf) where clearly damaged.

I also cleaned the laser couple of times just to be sure its clean. I tested both motors with DC supply and they are working great. There is also nice visual laser and focus seems to move clearly.

The service manual of Century doesn’t have the layout for this kind of PCB. So it is making the fixing a little bit more difficult.

If you did find some specific component to be damaged let me know. And if anybody has good ideas let them fly.

Pete

Re: Beocenter 9300 cd fault

yachadm — Thu, 21 Oct 2010 09:34:45 GMT

Very good Martin!

Close enough - it was the -12V line.

The 6800uF services the +12V line.

Menahem

Re: Beocenter 9300 cd fault

Die_Bogener — Tue, 19 Oct 2010 13:15:05 GMT

Yes, i have seen this before with the missing 2200uf cap. The cd drives are different, one power supply voltage line is not used any more. So the cap is not necessary any more.

I dont remember which voltage is gone, but i have had both types of the BC9300 in repair. The older drive had the cap, the newer drive did not.

Was it the negative -9V line...?