wierd cd player question - help needed

[patchquinn]

wierd cd player question

I got a sony portable cd/radio/cassette player about 5 years old. THe cd player had not been working for a long time, and had not been tried. Then recently I tried it with a cd burned by myself on a pc. To my surprise the cd played fine. I tried another burned cd and that too played fine. Then I tried a store bought cd and the player seemd to skip alot and struggle to find tracks. (i would have expected this with the burned cd) Then after a few hours play it also had the same problem with burned cds. I have tried cleaning the lens, to see if this was the problem but it seems to have little affect. Cant seem to find the problem. Any suggestions. Now it wont even locate tracks.

 

[Bik]

Hi!

You can try to find very small trim. pot. close to the laser and turn it very little clockwise(to rigth). With this you increase the current through laser so you increase laser beam energy.

Regards
Bik.

 

[MielGibson]

If that doesn't work, or if it only works for a while, you're gonna have to change the pickup.

 

[crono]

hi,
If the CD is of a recent edition it can be "copy protected".
This with some old CD-Player can be a problem.

 

[sick_man]

the problem you have is simple


dry joints and brocken solder connections
also dry capacitors in the +-15 v supply
this will also supply 5 v

the - voltage is used too give lense correction
and also in the audio stages

a simple replace method for all electrolytic caps that look at all suspect resolder the whole board

if you smoke
take the pickup unit completely off the sled
clean the whole lense assembley by removing the black cover from the lense and use alchohole spray too remove and particular build up on prysms and other optics and a little few cigarette papers too drag clean alll the lenses {use ver light one here are blue rizla}
they give some abbrasion without scoring the glass you will also find a small pool of alchohole is good

note a similar alchohole trick works fine for epson colour printers

take an old cartridge make a hole use a syring too place 1cc alchohole in the cartrige and seal with a little tape
{also buy some new cartrige}

then take the old one out the shell of the printer head

make a pool of alchohole in the running box for the printer and place a cloth in too cover over
run more alchohole in
and leave ina dark place for a few hours or overnight

then take out the cloth plug in the older catridge and run thru

till its starts too print


now reset plug in the new catridge and run it in a few times
cleaning and charging it

you will find the slots will have eased off the dryed ink inside the jets and it will print
{if at this stage it wont print a trace
use the cleaner program from windows {sometimes a flag gets set in some printers too say service and you need too reset it too get all the jets again }

alchohole used isopropile but ethyle {boooze} will do if it is 99.6 or better {called dry alchohole}








fully clean and polish the slead runners
and clean and crap from the phospher bronse runners on the pickup
{use a cotton bud and some alchohole too fully clean the holes and slots etc
then carefully reassemble all
}

only after doing this try adjusting any pots

i personaly plump for a dry 1 uf cap on the timing genorator chip

but replacing the dodge ones {use an esr and capacitance meter}
to test any that look good

a perfect looking one can have very strange values as the elctrolyte dryes out like a lead acid cell becoming strange.... then bang it cotton wools the case////


so also watch for heat sensative zener
use a hair dryer too heat it {or a blanket too bring on the symptoms}
or use the freezer to get it too run then spray round {you can find out if it is an electronics fault on an hdd controller {on board card too hdd drive} the same way {then look for same model same issue one with a gubbedplatter }

and some freeze spray or haridryer with nozzel too test candidates
if the cap and solder/ clean job dosnt work



ill finish by saying in over 20 years ive not replaced a cd head

a laser diode dosnt deplete as fast as you may think
with most giving far in excess of 20 million hours thats lots more than 5 years

experiance of esp hot countrys and cool weather of europe are both as good as each others at "drying " the elektrolyte out

it is a portable unit so expect heaps of dry joints and brocken interconnects

it could also need the timing xtals taken out and reversed check if they are oscillating correctly
as the impuritys become one ended with time in quarts

just replace the head
or its a blocked up epson...or other....
policy
from people is what kills the trade


however like batteries

i recomend this

the longest lasting battery used is about 5 years for ua
caps effectivly deplete with time as ua flow across them
el facto reverso .:.:

replace all capacitors after 5 years}
in 1952 you used too replace all the capacitors in a radio every time it came with just one gone {light bulb policy if you put them in all at once its sods law they will all need replaced at once }