Yamaha RXV 465 no display and power problem

[hemant_2222]

Re: Yamaha RXV 465 no display and power problem

Sorry i mean, do i need to check the +B and -B, as they are lower then 50v.

Also, i dont have the Q201 in the ckt.

[R_J]

Re: Yamaha RXV 465 no display and power problem

Do i need to check the low voltage 25 and 27v or this is controlled by the processor?

Do you mean +5 volts and +3.3 and lower, yes.
Page 112, there is +5.5v into ic21, it should output 3.4M, there is also Q200 it should output +3.3S, but this voltage is switched by Q201, Do you have 3.4 volts on Q201 base?

[hemant_2222]

Re: Yamaha RXV 465 no display and power problem

Do i need to check the low voltage 25 and 27v or this is controlled by the processor?

[hemant_2222]

Re: Yamaha RXV 465 no display and power problem

Thank you R_J for your interest in helping me on this.
Voltages between F1 and F2 is 5 vac ( measured with no dmm pin on ground )

Output of IC 103 is 11.3 v
Output of IC 104 IS -12.7v
+B is 25.4 v
-B is -27.1v
-VP is -39.5v dc

Also, nothing on display comes up when STRAIGHT and standby/on is pressed and hold.

All these measurements were done with the direct+tone control+standby press and hold method.
Will be checking for the low +Band -B readings.

Please suggest if i am missing anything.

Regards,

[R_J]

Re: Yamaha RXV 465 no display and power problem

A couple voltages need for the FL display to work are filament voltage which are about 3-4 volts AC and -VP which is around -30 volts

Page 115, plug CB403, you should measure 3-4 vac between the F1 & F2 pins and -30 vdc from ground to -VP
Other voltages to check are: page 117
+ & - 12 volts from ic103 & ic104
+Bv & -Bv should be around +&- 50vdc, they supply the stk-*** ic's You said you measured close to o volts on the R1046 & R1068 so I suspect the stk ic's are ok.
When you press the power button you should here a relay click, that is the one turning on the main transformer.

With the unit in standby, press and hold the "STRAIGHT" button and press standby/on , do you get a menu?

[hemant_2222]

Hi,

I am looking for getting some assistance regarding the above amplifier.

In present condition, when power switch is pressed, i only hear a relay click, so it is in protection mode.

When direct + tone control and stand by is pressed for some time, it gives me three relay clicks

1. For turning on the small standby power supply.
2. For the supply of the power to the amplifier board.
3. For the speaker relays.

(all these are my guess).

when turned on by the 3 buttons pressed it remains on but no display.

Till now i have checked only for the DC output at the emitter resistor and there is a small ( 2 to 5 volts ) dc on them as the first relay clicks, then it settles to almost 0 volts.

Please help me in getting further with the diagnosis of this unit. i have the required testing and measurement tools and the schematic.

i am stuck

Regards,
Hemant.