the 500 watt X-channel amp has a pull assembly. 2 fans total (see below)
service_manual - service manual can be found here.
blax500_fans - 2 fans total,
2 in front (pull);
24Vdc/0.17A; 80x25mm; 3 wire lock rotor; 38.8 CFM; 3110NL-05W-B59 originally. Replacement: 3110KL-05W-B69-D00 (B69 is 41CFM but can't find others in stock) from Newark or Digikey ($10/each)
Power Supply Fan -
the internal power supply module needs 1 fan below:
24Vdc/0.06A; 60x25mm; 3 wire lock rotor (pulse sensor); 18.7 CFM; Sanyo Denki 109R0624H4D011 originally. Replacement: 109R0624H401 from digikey ($11/each)
BLAX500
BLAX500
BLAX500
BLAX500
P/S
P/S
BLAX500
BLAX500
BLAX500
BLAX500
BLAX500
P/S
P/S
P/S
P/S
P/S