Yamaha Aventage RX-A810 does not turn on

Sir JPfx . . . . .


Looks like you need to confirm that F3702 and PARTICULARLY that F3701 are good. If so, then apply AC power and test to see if there is being 5VDC at my RED arrow mark up.
If so, then confirm if the BLUE marked 3.3VDC and 5VDC supplies are also present .

RE . . . . query . . .
what/where is PRY ??
That is the logic drive , to the RY371 relay that then powers up the B E E E E E EG power supply.



PARTIAL SCHEMATIC BLOCK REFERENCE . . . . .



73's de Edd . . . . .

Depression is merely anger without any expressed enthusiasm.

 

Use extreme care in this area as you are working with an un-isolated AC line.

Can you measure the voltage RY371? Not to ground, but directly across the relay coil. Should be near 5 volts. With 5 volts across the relay coil,. it should pull in and energize the main transformer. Sounds like you are say RY371 is not pulling in.

[edit: In your first post, you indicated 5 volts on PRY. Is that what you see on the top of the relay coil or is that what you see at the based of Q3702?]

 

That wording is confusing to me. Do you have that 5.5 volts from one coil terminal to the other coil terminal, or do you have that voltage from one coil terminal to ground?

It sounds like you probably have 5.5 volts from one coil terminal to ground. So the "AC-DC Converter" is working. But if you have no voltage on the voltage on the base of Q3702 then the system controller is not generating the 'ON' signal.

What I found online for a schematic is really more of a block diagram. It's going to be very difficult to troubleshoot from that.

 

Sir JPfx . . . . .

" Mah fren " . . . and you are my friend . . . . you do realize that you have yourself , one overall COMMMM - PLEXXXXX piece of equipment there . . . do you not ?
Along with all of the hollow feelings, in the pit of your stomach, when u see its schematics and documentations prolific use of " NO REPLACEMENT PART AVAILABLE. "

Now, does any thing light up on the front of your unit, if even only blinking for just an instant, at your attempted turn on with the main power switch ?
You can just hope that this units problem, relates to a power supply, audio power output / overload protection circuit fault. ( Most do ! )

Since this units design, incorporates a discrete part build up of its audio power output stages circuitry, why not look for sometthing simple first, even before checking the main power supply(s).

Find the units . . . . . " HEAT SINK CITY " . . . . . and on it, there should be ~ 6 sets of complementary PNP/NPN power output transistors being found heatsinked.
They will be of part numbers 2SA1695 and 2SC4468 markings.
In a NO POWER TO THE UNIT test . . . . . .
Place your meter in its lowest ohms test range . . . short its probes to see how a dead short displays . . . . and then test from Collector-to-Emitter on all of the units aforementioned power output transistors, to see if you might be ever so lucky as to find a shorted one(s).

Initially performing that test , see how you come out on that ?

FIO . . . . in later testing, you will be expecting a 2 .7Vdc logic ON level to activate the base of the Q 3702 relay driver transistor for its relay, which you are already being familiar with.

Considering the speed of the DC voltage blip that you might just find initially popping up . . . . on and then off . . . . . in case of default, on that Q3702 base . . . . .are you a scope person . . . familiar with + triggered, vert DC coupling mode analysis of a + going pulse ?

If not, I will give you a work-around.

AFTER THOUGHT . . . .
Has THIS unit been successfully working previously, with the same 220-120 power converter ?


ZUJ ing . . . . .

73's de Edd . . . . .


All syllogisms have three parts; therefore this is not being a syllogism.