The main board and power supply board all use Japanese capacitor and audio grade! What a waste for this WM8740 DAC also.
I take out the dvd rom and use a USB to parallel connector to put that into my computer but the rom cannot detect CD or DVD. I am think it is the laser issue. Later I observed one capacitor body a bit dirty and looks like chemical contamination. I take it out and measure it, oh it cannot be measure at all! totally dead. Thus I start to take out few more capacitors and found most of them are almost dead or left 10-20% of capacitance value with high internal resistance. So action is to change all the smd capacitor on the dvd rom. After that the computer connector is able to read CD and DVD disc!!!
As usual, do clean up and touch up with paint pen on any rusty casing on the set.
Lesson Learnt, do not use Korean made spare part in your high end product! they all use cheapy capacitors which can last 5-10 years only.
Still have a bit issue as some CD cannot be read when power up. Only able to read after playing for 15 mins. Anyway I have order a laser head for this CD rom drive and will replace it to see if better.