PD-H300 not recognising CD's

Firstly I'm an amateur so this is based on my opinions and all advice is without warranty. I had the same problem, no disk, just a clicking sound and no disc rotation. I removed the cover and attempted to clean the lens. This did work a little. The solution was a new laser unit a ? Sony ks-210a this unit was bought cheaply off eBay for eight pounds.
The spring that keeps the lens in position is made of plastic and fails with age, the laser ? lens cannot position in order to read the disc and if it can't read the disc it thinks there's no disk and that's why it doesn't spin it up.
Ok so now we know the reason let's change the part. Remove the case after disconnecting the unit from the mains leaving it for twenty minutes to ? discharge any capacitors. You will see the tray that holds the cd. Around the edge are four screws which engage with the metal case. Remove these and lift the rear end first to remove unit taking care to disconnect the four electrical connectors two on the side of the board and two on the rear of the laser pickup( red and White) note the position of the wires. Turn the removed unit upside down and you will see four springs held by small Phillips head screws. Remove these. The laser head is held by a sliding bar. Release this by moving the retaining clip to the side and withdraw the bar to remove the laser head. You may have to release the White cog which engages with the grooved slide on the laser head, to do this just pinch the rear of the shaft of the cog and withdraw it. Now for the new laser head, these are sensitive to static, so earth yourself ? by touching something metal ie, door handle to discharge any static. Position the new head and replace the slide bar, screw the four Phillips screws back down. Your almost done. The new unit has an anti static solder blob which protects the laser unit in transit, this has to be removed. You will find it behind the red and White connectors on the head at the bottom left hand corner of the laser head board. Carefully remove this with a soldering iron. Now fully reassemble. You should find for eight pounds or less you have a new cd player!? 

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On my PD-H3000 the problem varied, sometimes it would start the motor, sometimes not. Sometimes it would operate the lens transit motor, sometimes not. I checked these multi way conectors - there are 3. One is a ribbon cable header connection - very delicate. I found that reseating all the connecters did the trick. BE CAREFUL not to strain soldered joints etc. Ease the connectors in and out with infinite care!

I have an old pioneer cd multi pdc-p30c. i need instructions to operate. problems with playing cd

Had the same problem with a Nakamichi. It was caused by an old / inefficient belt that was supposed to drive the laser up7down to search the disk. The motor and all gears were fine, only problem was that the belt 'slipped' and did not drive the system as planned. Everything else was fine. Replaced the belt with a rubber band to verify it was the problem and all worked fine. By the way - original Nakamichi parts are close to impossible to get. Don't buy Nakamichi if you live in Europe or the US

FOLLOWING ON FROM MY REPORTED PROBLEM I WAS DETERMINED TO FIX IT.
I REMOVED THE OUTER CASE ( AFTER UNPLUGGING THE UNIT ) AND WET CLEANED THE LENS WITH METHATED SPIRIT. THAT CURED THE DISC RECOGNITION PROBLEM BUT THE MOTOR WAS NOT STARTING EVERY TIME.
VERY CAREFULLY I MANAGED TO GET A LITTLE WD40 ON THE MOTOR SHAFT AND HEY PRESTO IT NOW WORKS OK EVERY TIME.
HOPE THIS HELPS SOMEONE.

Who ever said that is WRONG. Do not do that . Dust it maybe but no... what happens is you need to get good qualities when burning songs. Sony's are great and u need to burn those cds at a low speed 8x or even 1x. CD players that are less than 200 bucks are not worth buying. trust me. Reason for burning them slowly is so that your cd player can be able to read. the slower u burn it the deeper the burn. Also quaulity of blank cds counts. get quality trust me.

Yes, most probably cleaning the lens will be helpfull. Dip the cotton part of a cotton stick in some ethyl alcohol and with this cotton wipe very softly over the lens. Preferably use some lint-free cotton or eventually lint free tissue,which you can buy in a photogaphy retail shop. Note, if you're smoker you might to repeat this in the future. Keeping CD's clean of course is recommandable. Lasers are not eternal; their power output will go down slightly after a "long" service; cleaning won't help in that case.