Yamaha RX-V863

[ga70gto]

Re: Yamaha RX-V863

Hey again Bud. Your question about the transistor not being turned on made me wonder about how does the PRY (power relay?) wire get power since the power first must go through the Function 3 board (pg 113). as we already know the diagram shows numerous components that my board doesn't use such as the ic's but it does use D2514 (bridge rectifier). The diagram clearly shows the leads of the board mounted transformer going directly to D2514 with 4.8 (volts) in red. I only have 4.2 volts on the AC scale. it further shows an output of 12.5 (volts), I only have 7.2 volts on the DC scale, that's me 'assuming" that once the voltage passes through the rectifier it becomes DC. This 12.5 volts not only goes to the onboard relay but to pin S10 of connector W2501 which then goes to connector CB33 of the Digital 2/5 page. So, this is an output voltage of the function 3 board? What if 7 volts on this line isn't enough to operate whatever it is that in turn goes to the PRY wire? I've been using the chassis as ground for these tests because pin "MG" of connector W2501is labeled "E" on the Digital board which I take to mean "earth" or ground and I have excellent continuity to ground on this pin (less than 1 ohm). So one of my questions is how did they arrive at 12.5 (volts) as the output of D2514 (bridge rectifier) and of course why do I have only 7 volts?
Thanks again, Pete

[budm]

Re: Yamaha RX-V863

I have a feeling you are not getting the command ON signal (PRY) pin to turn on the transistor, I would check that first.
This unit is also a little confusing due to the boards can be stuffed with parts in so many way for each country, so not all the parts are on the boards.

[ga70gto]

Re: Yamaha RX-V863

Thanks Bud. Even though I say it time and again I really do appreciate the help and guidance. Sometimes on cars what appears to be a complex repair can be a simple repair if someone has been there before seen it and done it. I was hoping maybe someone had seen this before on a similar unit. On cars we sometimes do a "shotgun" repair where we throw several items at a problem at one time to try and repair a problem. I think on this board I'll replace both transistors Q2502 and Q2503 along with C2504 and C2506 capacitors and D2514 diode bridge and see what happens.

Pete

[budm]

Re: Yamaha RX-V863

Sorry, I screwed up, it is Q2502 TO-18 for driving the relay RY251. Q2510 is not used in your board version.

[ga70gto]

Re: Yamaha RX-V863

It appears Q2510 would have been located on the bottom of the board and would have been surface mount. I checked both boards, found the Q2510 label but there is no component in that spot. The manual describes it as a digital transistor. You can see the label on the picture I attached of the bottom of the board.

Thanks again Bud for your continued help.

[budm]

Re: Yamaha RX-V863

I believe its a Rx-v863U as you had mentioned. the rear lists 120v and the front panel controls seem to match up with the front panel in the manual. The rear of the unit only lists RX-V863, no "U" or any other suffix.

There is NO audible click from the relay and as you noticed there are many components listed on the schematic that aren't present on the board.

So the question is why isn't the relay being commanded to close? As I mentioned before I did replace the relay on the original board because on vehicles I've heard relays click but that didn't necessarily mean voltage was transferred through the contacts.

Q2510 is the relay driver has to get about 5V on the connector W2501 'PRY' pin which is the power relay on command signal from the processor to turn on the relay when the power switch is activated, see the PDF I had attached earlier.

[ga70gto]

Re: Yamaha RX-V863

Clutchbox......one of the first things I did was to resolder many of the connections hoping there would be a cold solder joint, no luck.........thanks for the idea though.

[ga70gto]

Re: Yamaha RX-V863

I believe its a Rx-v863U as you had mentioned. the rear lists 120v and the front panel controls seem to match up with the front panel in the manual. The rear of the unit only lists RX-V863, no "U" or any other suffix.

There is NO audible click from the relay and as you noticed there are many components listed on the schematic that aren't present on the board.

So the question is why isn't the relay being commanded to close? As I mentioned before I did replace the relay on the original board because on vehicles I've heard relays click but that didn't necessarily mean voltage was transferred through the contacts.

[Clutchbox]

Re: Yamaha RX-V863

Are the mains-plug solderconnections okay?

[budm]

Re: Yamaha RX-V863

BTW, what is your exact model? RXV-863U?

[budm]

Re: Yamaha RX-V863

Hmm, your board is not using lots of parts as shown in the diagram. I need to study the service manual more in deep details to see what are actually being used on your board.
It does have C2513 so that section is correct.

[budm]

Re: Yamaha RX-V863

OK, I look at the diagram for the FUNCTION-3 board, as you can see in the schematic, the is a relay contact snubber cap C2513 (0.01uf 250V) across the relay contact, so when the relay contact is not close you will see 120VAC at the transformer connector but the Xc of the cap is very high which will not allow much of the current to flow through the transformer winding or the load connected to the switched OUTLET, that is why you see the ACV drop to almost nothing when the transformer is connected or the lamp.
So basically the relay is not being turned by the processor I assumed if you did not hear the relay kicks in when power switch is activated.
Or the relay may be bad if you do hear it clicks, so did you hear the relay on that small click on or not?

[ga70gto]

Re: Yamaha RX-V863

Bud, I became bored so here are a few pics to look over. let me know if you need different angles or other boards removed for clarity.

Pete

[budm]

Re: Yamaha RX-V863

Black probe of the ACV meter should be at the AC INPUT CONNECTOR NEUTRAL WIRE (WHITE) you need to leave it on this NEUTRAL while you are tracing the LINE VOLTAGE, then use the read probe to trace the ACV all the way from the AC input connector Black wire and then all the way to the Black wire of the main power transformer.
It is the same as leaving your Black meter probe on the car chassis then you use the read probe to find out where the Voltage disappear, same concept, we are just dealing with jut Primary AC at this point.
Primary AC, WHITE wire is neutral, Black wire is HOT (LINE/PHASE).
Enclosed is the PDF of that small power supply board FUNCTION 3.

[ga70gto]

Re: Yamaha RX-V863

Yes, it was my understanding that because I had this "stray" voltage the contacts were closed. I will post pics tomorrow and bring my fluke meter from work to recheck these measurements. I've worked on cars for 30 years so DC stuff i'm familiar with, AC i haven't done much other than house wiring.

Pete

[ga70gto]

Re: Yamaha RX-V863

yes, I had my black meter lead back probing the line in connector and using the red probe to check for voltages and have those stray voltages at the fuses. because it's easier I'm working with the spare power source which is out of the reciever and on the bench, it is NOT connected to the main power transformer. those measurements I gave you were from the small transformer mounted on the board. I do have the manual downloaded.

[budm]

Re: Yamaha RX-V863

Thanks again Bud. you can see I entered my post two hours after yours so it looks like to me the problem must be on this board and why aren't the relay contacts being closed?? One other thing, before I replaced anything on the board I plugged in the desk lamp to a switched outlet and sprayed each component with component cooler to see if voltage would be applied to the lamp, it made no difference.

But in post 1 you said the RELAY CLOSED its contacts.
it seems to power up and close a relay on that board which then provides line voltage (110v) to the main transformer

[budm]

Re: Yamaha RX-V863

BTW, I need good straight shot pictures of the top and the bottom side of the board and the whole inside of the unit.

[ga70gto]

Re: Yamaha RX-V863

Thanks again Bud. you can see I entered my post two hours after yours so it looks like to me the problem must be on this board and why aren't the relay contacts being closed?? One other thing, before I replaced anything on the board I plugged in the desk lamp to a switched outlet and sprayed each component with component cooler to see if voltage would be applied to the lamp, it made no difference.

[budm]

Re: Yamaha RX-V863

There should be no strange Voltage with ref to Neutral and the input side of the fuse, or at the out put side the fuse, or at the input side of the relay contact, or at the output side of the relay contact. All those point should show 120VAC ref to neutral WITH THE TRANSFORMER CONNECTED.

measuring the two leads of the primary side of the transformer I have line voltage, measuring across the secondary side I have 14.2v. the resistance of the primary side is 730 ohms, the secondary side 16 ohms.
Is this the reading of the main power transformer?
Did you download the service manual?
What ACV do you have between the two relay contacts (you put the probes on each legs of the relay contacts) when the relay is on and the transformer connected?
Same for fuse.