Adjustment - JVC RX-7030VBK Service Manual

3.1 Adjustment method
Tuner section
1. Tuner range
FM 87.5MHz to 108.0MHz
AM 530kHz to 1710kHz
Power amplifier section
Adjustment of idling current
Measurement location B2204-B2205 (Lch), B2213-B2214 (Rch)
Adjustment part VR787 (Lch), VR788 (Rch)
Attention:
This adjustment does not obtain a correct adjustment value immediately after the amplifier is used (state that an in-
ternal temperature has risen).
Please adjust, after you turn off amplifier and internal temperature falls.
<Adjustment method>
(1) Set the volume control to minimum during this adjustment. (No signal & No load)
(2) Set the surround mode OFF.
(3) Turn VR787 and VR788 fully counterclockwise to warm up before adjustment.
If the heat sink is already warm from previous use the correct adjustment can not be made.
(4) For L-ch, connect a DC voltmeter between B2204 and B2205 (Lch) and, connect it between B2213 and B2214 (Rch).
(5) 30 minutes later after power on, adjust VR787 for Lch, or VR788 for Rch so that the DC voltmeter value has 1mV to 10mV.
• It is not abnormal though the idling current might not become 0mA even if it is finished to turn variable resistance (VR787,
VR788) in the direction of counterclockwise.
1-12 (No.22058)
SECTION 3

Adjustment

Front amp. board (L)
VR787
Front amp. board (R)
VR788
VR787 (Lch)
B2204, B2205 (Lch)
VR788 (Rch)
B2213, B2214 (Rch)