PS I also remember reading another thread where one of the members had also recommended upgrading the main power supply capacitor C529 (3300uF/16V) with 10000uF/16V and replacing the 4 diodes D515-517 (1N4001) with faster 3A diodes. I haven't done this as yet.
Reviving an old thread, but thought this info may prove useful.
There is a mod for these players, re discs skipping / no disc errors.
C521 / C541
C522 / C524
C520 / C540
If the customer has a complaint about a CD Player not being able to play a CDR or out of tolerance discs,
try replacing these capacitors with the following values. This will also provide a cure on some players for
“NO DISC” message.
C520 / C521 / C522 / C524: - - C540 / C541:
C122 is changed to 2.7pF - - C122 is changed to 2.7pF
C123 is changed to 0.01µF - - C123 is changed to 0.01µF
C124 is changed to 22pF - - C124 is changed to 22pF
C311 is changed to 220pF
This change has been implemented in production from serial number:
G19C52113901 - C521/C
G19C54108101 – C541/AH
G19C54108401 – C541/C
Does this also apply to the NAD 522 (no 'C', predesessor of the C series) ??
The NAD 522 came with the nasty Sanyo SF-P101 transport too.