Re: Yamahaha RX-V679 DC PRT High
Thank you. I'll throw some leads on there and flex it around and see if the problem reproduces itself when I have a little time on my hands. I appreciate everyone's help, very considerate.
peterwheat
Member
Last Activity: 08-10-2020, 02:51 PM
Joined: 08-04-2020
Location: Huntsville
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Re: Yamahaha RX-V679 DC PRT High
How would I go about checking the main amplifier voltages?Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Haha hopefully no servos buried in here. Watched the -12.4 volt line as I flexed and nothing weird happened. When the problem was occurring, still -12.4. Pressed on all the components I could find with my handy chopstick to see if anything wiggled free and popped the protection, but nothing. Ended up sliding a piece of rubber mat under the main board (didn't block any air holes, but I know it'll heat it up more than usual) sewed it back up, and it's firing away. I'm assuming there's a loose component in there somewhere that is giving me the issue....Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
I logged every group of screws so that wouldn't happen, so hopefully not that. Flexing the main board a little causes voltage at the speaker terminals and distorted sound, flexing it back stops the voltage. Poking around for loose components as best I can, but a bit difficult to touch everything while all connected. Can you flow these boards in the oven?...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
I have the chassis connected with alligator clips when dissembled. In fact, the issue gets worse with more assembly. Should I just put it back in use taken apart?
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Re: Yamahaha RX-V679 DC PRT High
The standalone testing of the speaker varies as I am putting the unit back together. I tested the in wall speakers using a different receiver and they sound perfect, so the issue is certainly with the receiver....Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
When the unit was originally plugged in (I bought a house and it came with it, plugged into in wall speakers) the sound was very distorted and muffled at any volumes higher than a whisper. Out of curiosity, I had a speaker plugged in while taking apart, and tested with the unit dissembled. It sounded great, and the voltages at the speaker terminals were normal (read < 0.01 volts). However, as I put it back together, it seemed that the problem reappeared. I'm suspecting a loose connection somewhere possibly? What could cause all the speaker terminals...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
SR: 0.353
SL: 0.302
C: 0.300
FR: 0.358
FL: 0.305
SBR: -0.009
SBL: 0.814
Those measurements are with all channels selected.
waiting on it to kick off so I can measure the jumper now....Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Q1002 is in a Y shape, from the bottom of main board
-0.45V 0V
56.58V...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Reads at -12.2VLeave a comment:
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Re: Yamahaha RX-V679 DC PRT High
On the main board, correct?Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Checked these voltages, all correct. (within 5% or so)...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Should I just be checking voltages coming out of the power supply then?...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Schematic should be in the service manual above, I can attach the main board pdf possibly?...Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Update:
I put things back together so I could reverify some voltages. I checked all the active speaker terminals for voltage again, and everything that's active is reading about 400 mV, with close to 0 on the non active channels. I had a speaker hooked up to one of them, and it sounded very distorted unless it was at a whisper like loudness.Leave a comment:
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Re: Yamahaha RX-V679 DC PRT High
Which ones are those?
Not that I am aware of, but frankly I'm not that knowledgeable on receiver electronics.Leave a comment:
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Yamahaha RX-V679 DC PRT High
Hey all,
I have a Yamaha RX-V679 that is entering protection mode after a few seconds of turning on. Shows "DC PRT 77H" error when I disable the auto protection.
All speaker terminals read ~0.4 volts across, except for the surrounds, which read 0 volts for right and ~0.9 volts on the left, which increases until the receiver kicks off. I'm thinking this is my problem child.
I took it apart and started testing the main output transistors, and didn't see anything blown open (I did this without desoldering, however I compared to nextdoor channel... -
Re: New Members - please post your introductions here
Hey from the South. Just looking to fix a broken Yamaha rx-v679
Thanks!Leave a comment:
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