hifi engine

Denon DCD 1000 CD player

Can anyone advise what is wrong with my denon cd player. It starts up ok playing discs then at random time there is a crackle through speakers and simultaneously the cd player stops and then usually have difficulty in getting it to replay either same or different cd. I have opened up and cleaned lens very carefully and all associted rails etc but problem still recurs on a random basis. If this requires replacement of laser I assume it is not worth repairing/ unable to source replacement part as this is old machine although otherwise plays ok
any suggections welcome