The Jolida 603 was plagued with transport problems. This was due to Sony unleashing a batch of bad transports on Jolida.
I was the first dealer in the US to have this player in my system and this player worked flawlessly for 18 months and is still working perfectly today without a hitch. Unfortunatley, I cannot say the same for many customers who purchased this player.
Did you purchase this as a new unit? Leftover inventory? What color is the display in your player, as this would indicate if it was from the original production which had all the problems.
It is a very good sounding machine when working properly but all the problems are what lead to Jolida discontinuing this model and introducing the JD100 which is a totally different machine.
For the most part, you may want to contact Jolida to see if they still have the proper parts to upgrade this player to proper working order. They would be able to give you more information based on the serial number.