WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Руководство пользователя

Страница: 123 / 194

123
20 W Stereo Audio Amplifier
resistance shown on the ohmmeter will be quite low, in the neighborhood of 0.5 ohms.
This is normal.
• Move the headphone plug to the other front panel headphone jack. Touch the red lead of
the ohmmeter to the right channel 8 Ohm terminal and confirm that a click is heard in the
right channel headphone. Finally, touch the red lead of the ohmmeter to the left channel 8
Ohm terminal and confirm that a click is heard in the left channel headphone.
If the results detailed above are not observed, recheck the wiring of the headphone jacks and
the speaker PWBs. Do not move forward until these tests are successfully completed.
5.6.12 Power Management Module
Find the power management PWB, completed previously. This board will be mounted with the
component side facing inward toward the chassis top plate; the foil side will face the chassis
bottom panel. It will be necessary, therefore, to make all connections to the PWB before it is
secured in place.
L-shaped brackets are provided to temporarily mount the power management PWB on its side
in order to make connections, and later for maintenance if needed. Attach the brackets to the front
mounting posts adjacent to the power transformer leads. Temporarily mount the PWB at a right
angle to the chassis deck using the #6 hardware provided. Important : the brackets should rest
against the component side of the board. If mounted with the brackets against the foil side of the
board, component damage may result. See Figure 6.1.
When making connections to the power management PWB, support the board from the foil
side to prevent cracking the PWB at the right angle attachment points.
– Prepare a 26-inch long #22 black wire. Attach a spade terminal to one end of the wire;
connect to the center terminal of the front panel power switch, SW51 . It may be helpful to
turn the switch body slightly to improve access to the terminal. Orient the barrel of the
connector so it is out of the way. Place a short piece of heat shrink tubing over the
connection and process (heat).
– Prepare a 26-inch long #22 black wire. Attach a spade terminal to one end of the wire;
connect to one of the outside terminals on the front panel power switch, SW51 . Place a
short piece of heat shrink tubing over the connection and process (heat).