powersoft K Series - Power Supply KALSU Removal; Power Supply KALSU Board Removal; Fan and Fan Driver Replacement; Fan and Fan Driver Replacement Procedure

INDEX
26
K6 K8 K10 K20 | SERVICE MANUAL
To remove the KALSU board, access to the power supply
control board is needed. This can be pulled out as shown
in (Fig. 31, 32)
9. Power Supply KALSU Removal:
(Fig. 31)
(Fig. 32)
To keep the amplier within the correct range of working temperatures, K Series amps have two fans controlled by NTC sensors and
microprocessor.
The fan’s correct working state is:
- fan speed increases when the amplier’s internal temperature rises
- fan is at full speed for approximately half a second at power up
- fan does not run in absence of input signal with an environmental temperature of 18°-20°
- fan runs at low speed when the amp reaches about 30°C
- with an environmental temperature of about 18°-20°C and a standard music program the amplier’s internal temperature should be
about 40°- 42°C and the fans should run at about 1/3 speed.
- should one of the fans not run (faulty fan or fan blocked from any external object), with an environmental temperature of about 18°-20°
and a standard input signal, the amplier’s internal temperature stabilizes at about 55°C.
- When the amplier internal temperature is approximately 55°C the fans should run at about half speed; at about 85°C they should run
at full speed. If one or both the fans are not working (for a fan fault or fan blocked from any external object) the amplier can over heat
in a few minutes.
Before beginning to remove the fans, please proceed in
discharging the power supply as illustrated in chapter 3.
Start by removing the rear panel: unscrew all the screws
highlighted in (Fig. 33, 34).
10. Fan and Fan Driver Replacement:
Removing the fan:
(Fig. 33)
(Fig. 34)