Marantz PM 710 DC Service Manual

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MANUAL

Siice only the unidemical parts beiv een the original model are listed, please use this manual lFlysheell
with the original model Pm700 lN version] service manual accordingly.

SERVICE
MANUAL

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1. INTRODUCTION

This service manual was prepared fer use by Authorized
Warranty Stations and contains service information for
the Marantz PMSOO/PM700 Stereo Console Amplifier.
Servicing information and voltage data included in this
manual are intended for use by knowledgeable and expe~
rienced personnel only. All instructions should be read
carefully. No attempt should be made to proceed without
a good understanding of circuitry operation,

The parts list furnishes complete ordering information.
Most replacement parts should be ordered from the
Marantz Company. However, a simple description is
included for parts which can be obtained locally.

2. PREsAMPLIFIER

The input signal from the PHONO-MMI or PHONO-MM2
terminal. selected with the SELECTOR SWITCH, is
applied to the PHONO AMP where it is RIAA-equalized
and amplified 36 dB.

fln PM700, the signal from the PHONO-MC terminal is
amplified 56 dB.)

The PHONO AMP output signal is returned to the
SELECTOR switch and is also fed to the RECORDING
SELECTOR (SJ04). The signals from the TUNER and
AUX/TAPE 3 terminals are applied to the SELECTOR
SWITCH (SJOI) and to the RECORDING SELECTOR
(SJ04). (PM700 only)

The signals from the TAPE I IN and TAPE 2 IN are
applied to the TAPE MONITOR SWITCH (SJ07I and
the RECORDING SELECTOR (SJ04).

One of five signals applied to the RECORDING
SELECTOR (SJ04I is selected with the RECORDING
SELECTOR and fed from the TAPE I OUT and TAPE
2 OUT terminals.

The signal from the SELECTOR SWITCH (SJOII is fed
to the TAPE MONITOR SWITCH (SJ07). MONO SW
(SHOI-ZI and then level controlled with the BALANCE
IRGOII and VOLUME (RGOZI controls.

In the volume control circuit, the signal is controlled
by the loudness control in the LOUDNESS circuit when
the LOUDNESS SWITCH (SGOI) is ON. The signal from
the VOLUME (R602) control is amplified 19 dB with the
FLAT AMP IOEOI-LCH. 0E02-RCH). then fed to the
EC DEFEAT SWITCH (SHOI-II. The amplified signal is
also fed to the ZONE CONTROL (GRAPHIC EQUALIZ-

ER) circuit. The ZONE CONTROL output signal is
applied to the E0 DEFEAT SWITCH (SHOI-ll.

The signal selected by the E0 DEFEAT SWITCH
(SHOII) is supplied to the main amplifier via the FILTER
SWITCH lSHOI-3 for PM500. SHOl-3 and SHOT-4 for
PM700l.

(J

. TROUBLESHOOTING ANALYSIS

1. Excessive line consumption
a. Check for shorting in 0N0'I through to AN04.
b. Check for any shorted transistors 0717 through to
0728.
c. Check for open 0715, 0716, 0743, 0744, R737
and R738.

2. No line consumption or zero bias voltage
3. Check line cord and fuse. Check for a shorted
0715 and 0716.
b. Check for open circuits in rectifiers 0717 through
to 0728 and 0N0] through to ON04 or for L001.

3. High hum and noise level
a. Check capacitors c421. C422. C803. C804. C811.
C812 and 0801 through to 0806.

4. POWER AMPLIFIER ADJUSTMENT

ADJUSTING IO LING CURRENT

Connect a DC voltmeter between the emitters of 0725
and 0727. Adjust R741 for 14 mV meter reading.
Perform similar adjustment to R742, 0726 and 0728.

5. POWER METER ADJUSTMENT

PM500

Connect an 89 load to the left speaker terminals.

Connect VTVM across the 80 load and an lkHz oscillator
to the left AUX/TAPE 3. Adjust the oscillator level for
a 20V VTVM reading. Adjust RX39 IL-CH) so that the
power meter indicates 50w. Perform the same adjustment
for the right channel (RXdOI.

PM700

Connect an 80 load to the left speaker terminals. Connect
VTVM across the SQ load and an lkHz oscillator to the