Pioneer CDXP23S is an old model and has been top useful for me to find this Manual. CD Player is still repaired.
Text excerpt from page 8 (click to view)
SRS-A57
REVISION HISTORY
Clicking the version allows you to jump to the revised page. Also, clicking the version at the upper right on the revised page allows you to jump to the next revised page. Ver. 1.1 1.0 Date 2001.07 2000.02 New Description of Revision RH board change (1-675-921-11 t 1-675-921-12).
(ECN-TAB00495)