CD Player doesn't detect disc sometimes

[Gartak]

I have a 6 month old Coby MP3 Discman (http://www.cobyusa.com/product/item2.php?curitm=MPCD550). All of a sudden, it stopped detecting discs. If I insist, removing and putting the same CD again several times, it will eventually detect and play it perfectly.

I disassembled it, cleaned lens, checked if the head assembly was stuck, all was ok. Lens go up and down trying to detect the disc, but when it fails to detect the disc, it displays "no disc" just after the lens stop moving and before the CD spins. Everytime the CD gets to the point of spinning, it works well, playing the CD. I noticed that when it was reassembled, it started to detect the CDs correctly more times than before.

Since warranty is over and it's not so cheap (US$49.88 at Amazon), I would like to fix this device myself. So I ask: how can I pinpoint the cause of the problem and fix it? Bad solders? Bad ribbon cables? I'm experienced with soldering, even SMDs, if that is necessary.

Thank you all in advance for any ideas.

 

[cm]

I had the same problem with my CD player. Changing the solved the problem. Tweeking the pot on the flex of the lazer ( very slightly ) got me a few more days of use before the lazer died.

It could also be that the flex circuit connecting lazer to the board is not connected properly. Make sure it is plug in all the way before you push the connector catch in. It could be that you have a badly assembled flex. If it still does not work....

 

[Gartak]

Thanks a lot for your reply!

Just one thing, I think you missed a word, you didn't say what exactly you replaced to fix your player. What was it?

Anyway I'll try to check the ribbon cable and I won't touch the trim, at least for now.

Thanks again!

 

[cm]

Sorry, my mind is fast by the fingers are weak.

I replaced the lazer module. It cost me about 10 USD ( Philips VAM1202 ). It is likley your lazer module is a Sony and should cost about 8 USD. However, since your player is so new, it is not likely to be the lazer unit.

Where are you in Brazil? I have been to Sao Paulo three times in the last six months and I love it. The people are so friendly and the city is so pretty. I will be back in Sao Paulo again in three weeks. Have to pick up some Portugese....

 

[Gartak]

Thanks for the explanation!

Last night I opened the thing again, diconnected and reconnected all ribbon cables I could, removed the main circuit board and pushed all components I could. Now the player seems to be working well again! At least 20 succesful CD detections, no more failures so far.

But I noticed some ugly solder joints in the board, I'm sure I'll have problems with this in the future, but I'll leave it as is for now.

Thanks for the help! About São Paulo, it's my city! I was born here. I like it very much, even if sometimes I think it's too crowded and violent. If you need help with anything in here, just tell me! My email is emarco@uol.com.br.

Thanks again!