Marantz SR9600 - Service Hints; AVSS Function Check; Cooling Fan Check; Overheat Protection Check

8
SERVICE HINTS
AVSS Function Check (P314 PWB)
AVSS is the function that switches B voltage automatically
depending on the volume of the input signal.
To check whether B voltage is switched or not, follow the
procedure below.
1. Check if B voltage is switched to High.
If maximum power (or +/-51V to +/-65V) can be output,
it is OK. IF wave form is clipped and maximum power is
not output, it is NG.
2. Check if B voltage is switched to Low.
If B voltage can be output to +/-33-40v, it is OK.
Note: Once B voltage is switched to High, it is kept High for
1 minute. B voltage is Low upon turning on the power
(initial status) if there is no signal input.
Cooling Fan Check (P254 PWB)
There is three speeds for the cooling fan, stop, Low Speed
and High Speed, depending on the temperature of the heat
sink.
Heat sink temperature is monitored with RN67, RN68,
thermo sensors for cooling fan.
If heat sink temperature becomes higher, resistance of the
sensors also becomes higher.
To check the cooling fan, connect test resisters to pin 1 - 5
(JN08) or pin 2 - 5 (JN08) where the thermo sensors are
connected.
Two sensors are in the both sides of a heat sink.
There are two ways of checking.
One of way, Remove either sensor and connect the test
resister. Other one, remove both sensors. And one connects
0 ohm and another connects test resistor.
The check of the thermo sensors RN67 and RN68 for Fan
uses a drier etc.
And check the resistance of a sensor. (RN67 and RN68)
Ambient temperature 20 to 30 degrees centigrade: Over 50
ohm
Overheat Protection Check (P254 PWB)
If monitored temperature of the heat sink goes overheat,
microcomputer shuts down the unit to stand-by mode.
Heat sink temperature is monitored with RN69, RN70,
thermo sensors for overheat.
To check the overheat protection function.
Connect test resisters to pin 3 - 5 (JN08) or pin 4 - 5 (JN08)
where the thermo sensors are connected.
Fan Speed Test Resister Value Temperature
1 Stop 0 - 220 (0 ohm) Under 60 °C
2 Low Speed 470 - 2.2 k (1.0 k ohm) 60 - 80 °C
3 High Speed Over 4.7k ohm (10 k ohm) Over 80 °C
AVSS Function Check (P314 PWB)
AVSS
ೞᏡƸЈщӭƷٻƖƞƴࣖơƯȑȯȸǢȳȗƷ
B
ᩓן
ǛЏǓஆƑǔೞᏡưƢŵ
B
ᩓןƷЏǓஆƑѣ˺ᄩᛐƸŴˌɦƷ૾ඥưᘍƍLJƢŵ
1. B
ᩓן
High
Џȁǧȃǯ
B
ᩓןƕ
±51V
᳸
±65V
LJƨƸܭ఍ЈщƕЈǕƹ
OK
ưƢŵ
ඬ࢟ƕǯȪȃȗƠƯܭ఍ЈщƕЈƳƍئӳƸ
NG
ƱƳǓLJ
Ƣŵ
2. B
ᩓן
Low
Џȁǧȃǯ
B
ᩓןƕ
±33V
᳸
±40V
ЈщƞǕǕƹ
OK
ưƢŵ
ͳᎋᲴɟࡇŴ
B
ᩓןƕ
High
ƴƳƬƨࢸƴ໯ӭλщƴƠƯNjŴ
ᩓן
High
ƷཞǛ
1
Ў᧓ƠLJƢŵᩓเ
ON
଺ᲢǤ
ȋǷȣȫ଺ᲣƴŴ໯ӭλщưƋǕƹŴ
B
ᩓןƸ
Low
ư
ѣ˺ƠLJƢŵ
Cooling Fan Check (P254 PWB)
Cooling Fan Ʒѣ˺ƸȒȸȈǷȳǯƷภࡇƴᡲѣƠƯ 1 STOP Ŵ
2 Low Speed Ŵ3 High Speed Ʒɤѣ˺ƕƋǓLJƢŵ
ȒȸȈǷȳǯƷภࡇƸ
Fan ဇภࡇǻȳǵȸ RN67 ŴRN68 ư౨
ЈƠƯƍLJƢŵ
ภࡇƕ᭗ƘƳǔƱŴǻȳǵȸƷ৽৴ƕ᭗ƘƳǓLJƢŵ
Fan ဇภࡇǻȳǵȸƕዓƞǕƯƍǔŴJN08 Ʒ 1 ȔȳƱ 5 Ȕ
ȳӏƼ
2 ȔȳƱ 5 Ȕȳƴ౨௹ဇƷ৽৴ǛዓƠƯ Cooling Fan
Ʒѣ˺ȁǧȃǯǛᘍƍLJƢŵ
ǻȳǵȸƸȒȸȈǷȳǯɲ
2 ሖ৑ƴƋǓLJƢŵ
౨௹ƴƸʚᡫǓƷ૾ඥƕƋǓLJƢŵ
ƻƱƭƸŴǻȳǵȸǛ༾૾ƣƭƸƣƠƯ౨௹৽৴ǛዓƢǔ૾
ඥŴNjƏƻƱƭƸ
2 Ʒ౨௹৽৴ǛဇƠƯŴɲ૾Ʒǻȳǵȸ
ǛٳƠ༾ƴ˯৽৴
(0) ǛӕǓ˄ƚNjƏ༾૾ƴ౨௹৽৴Ǜ
ዓƢǔ૾ඥƕƋǓLJƢŵ
Fan ဇภࡇǻȳǵȸ RN67 ŴRN68 ƷȁǧȃǯƸภࡇǻȳǵȸ
ƴȉȩǤȤȸƳƲư༏ǛɨƑƯᘍƍLJƢŵ
RN67 ŴRN68 ƷǷȧȸȈƷȁǧȃǯƸ RN67 ŴRN68 Ʒ৽৴
ǛยǓLJƢŵᲢࠝภᲢ
25éᲣư 50 ˌɥᲣ
Overheat Protection Check (P254 PWB)
ȒȸȈǷȳǯƷᢅ༏Ǜ౨ЈƠƯŴȞǤdzȳưǹǿȳȐǤȢȸȉ
ƴλǓLJƢŵ
ȒȸȈǷȳǯƷภࡇƸ
Heat ဇภࡇǻȳǵȸŴRN69 ŴRN70 ư
౨ЈƠƯƍLJƢŵ
ภࡇƕ᭗ƘƳǔƱŴǻȳǵȸƷ৽৴ƕ᭗ƘƳǓLJƢŵ
Heat ဇภࡇǻȳǵȸƕዓƞǕƯƍǔŴJN08 Ʒ 3 ȔȳƱ 5 Ȕ
ȳӏƼ
4 ȔȳƱ 5 Ȕȳƴ౨௹ဇƷ৽৴ǛዓƠƯȁǧȃǯƠLJ
Ƣŵ