Re: Yamaha RX-V577 - DC: PRT 000L
Update, after ordering a transistor tester (GM328), I'm back in business I actually ended up ordering 3 due to assembly issues with the first one.
I've went thru about a dozen Toshiba 2SC2713-GR.LF transistors from DigiKey, have 3 matched pairs, picking the middle set that both measure hfe = 287. Vbe also roughly matched at 651mV/650mV.
Time to install and get this thing back to normal.
stinkincaps
Member
Last Activity: 09-14-2020, 10:52 PM
Joined: 05-12-2020
Location: California
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Re: Yamaha RX-V577 - DC: PRT 000L
Thanks Petehall, I'll have to get a transistor tester. Not seeing that on my meters (Fluke, Extech).Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
That's interesting. I just put in NTE2410, came in pack of 2.
Where do I find matched pairs? Or if I have 6 of these, what is the chances of getting a match that works?
Thanks....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Voltages measured in protect mode is showing 50mV. (prior measurement showing 40mV was not in protect mode).
I'm not smart enough with analog circuits to figure out where the issue lies....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
The parts arrived and sat for a few weeks. Finally pulled the unit off the shelf and started pulling parts. C2135 was dead for sure, no capacitance measured. Replaced. I also replaced Q2107 & Q2114.
The rest of the suspect parts I pulled from the board and measured out of circuit, all came in fine.
The unit now powers up fine. I'm getting a 39-40 mV reading on R2249 (all 3 legs are the same). Other resistors are 0.000V. It was -9.8V before, so much better.
Should I be worried about 40mV there? I...Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Also found C2165 to have lower resistance. This one is a mlyar cap, hard to find. Seems like only NTE has it, so I'll order everything from there, as best they have it....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Found some components that don't meter like the others. Time to order some parts....Leave a comment:
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Re: Yamaha RX-V581 going into protection mode
Did you ever find out what it was? I'm trying to nail down a -10V offset on one of my channels (yamaha RX-V577).Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Thanks R_J,
To confirm, I'll power down and check device resistance & compare to good channel? Looking at everything from resistors, diodes, transistors and caps?Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Some voltage readings:...Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
All the ceramic resistors are 0V, except R2249, showing -9.8VDC on the 3 legs....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
That looks doable. Let me reassemble and pop the back off....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
I took the digital board and Operation(4) board out to get to the output transistors. Once I put the boards back, getting to measure more than 2 of these resistors (C + FL) will be a bit tricky to impossible....Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Service manual attached. What boards do I need to reconnect and power up to check these voltages?...Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Ok, the big transistors on the heat sink all seem to be not-shorted. Any advice on next step?
Thanks in advance.Leave a comment:
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Re: Yamaha RX-V577 - DC: PRT 000L
Thanks for the tip. So I'm looking on the MAIN amp board, powered off, measuring impedance on all transistors. Will have to do some disassembly first to get to them all.Leave a comment:
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Yamaha RX-V577 - DC: PRT 000L
Manual says DC output of power amplifier is abnormal.
Power supply board looks to be ok, 5.5V is good.
Looks like I need to go deeper, where do I start? -
Re: New Members - please post your introductions here
Hey everybody, I have a Yamaha RX-V577 that has seen little use over the past 4 years and suddenly died. Looking forward to fixing itLeave a comment:
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