Hi guys, I have this Yamaha for repair, the problem is when I push Power ON,, the amplifier goes Off in 1 second, I try Hard reset, same problem, I change all the capacitors on the Ic regulator circuit and same problem, I check all the audio output transistors all are good, I check voltage on Regulators board and I have a little low voltages on circuits like on 12 volts I have 11.6 volts, on -12 volts I have -11.4 volts , on 5 volts I have 4.81 volts, could someone tell me what I have to check now?
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Re: Yamaha RX-V3900
Look at this thread for information and things....
https://www.badcaps.net/forum/showth...t=yamaha+v3900
hopefully, you can get to the self-diagnostics and see what the results are.Last edited by budwich; 02-17-2022, 05:06 PM. -
Re: Yamaha RX-V3900
I try but I cannot because when I push Power On the amplifier shutoff immediatlyComment
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Re: Yamaha RX-V3900
what process are you following to get into the diagnostic menu? Follow the sequence in the manualComment
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Re: Yamaha RX-V3900
Self-diagnostic mode by holding down the 'enter' &preset tuning> buttons while pressing in the master on/off switch repeatedly many times but the message 'MAIN ON' stays on nothing else happening.I think the system has locked itself in.I try another thing , I push Info and Straight and put the Ac cord it's write Firmware update ( blinking) in the display but when I release these 2 buttons the amplifier goes OffLast edited by Fripacks; 02-19-2022, 09:43 AM.Comment
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Re: Yamaha RX-V3900
:-(... I have seen in the manual that if the system is in fault mode, you have to unplug it from the wall before trying to get into the self-diagnostics. Further, you don't keep repressing the power on key. According to the manual, you just press it once (to the ON position... it should be in the OFF position when unplugged) while holding the other two keys and wait for the appropriate display, then release them.Last edited by budwich; 02-19-2022, 12:48 PM.Comment
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Re: Yamaha RX-V3900
I try this thing too, always same problem, shut off in fraction of secondComment
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Re: Yamaha RX-V3900
just for confirmation.... you are using the master on/off button which is a "push in / out" button versus the "on/off standby" button which is a momentary button.
what's the history of the problem / unit?
there is a 9v "supply" along with -5v and 3.3v. You might list all the voltages that you checked on the power supply area specifically.Last edited by budwich; 02-21-2022, 12:35 PM.Comment
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Re: Yamaha RX-V3900
you might need to monitor the PDET line while you attempt your power up sequence to see what happens.
does the display light and display anything before it shuts down?Last edited by budwich; 02-21-2022, 09:48 PM.Comment
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Re: Yamaha RX-V3900
If it's going into protect due to over voltage or over current then you have to remove that condition first. The way to do that is to unplug one of the cables going from the hdmi board to the main board.
You'll have to have a look further or post some pictures as I have no idea about the receiver in question here.Comment
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Re: Yamaha RX-V3900
I try disconnect all connectors on HDMI board always same problem, see the photosAttached FilesComment
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Re: Yamaha RX-V3900
Someone?Comment
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Re: Yamaha RX-V3900
You can't disconnect ALL connectors. Try them one at a time or find the service manual for less guess work.Comment
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Re: Yamaha RX-V3900
Did you check the output voltages on the DCCNVT pcb?
I had an issue with the board, Channel 2 4.3v Dc. Rail was < 0.4VDC.
This was triggering the protect mode.
Note: During this fault you could not enter diagnostics mode, but could activate PSU’s to test voltages using the diag mode.
Replaced the DCCNVT board, problem resolved.Comment
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Belongs to my son and he just says it stopped turning on. Any help greatly appreciated. Theres 240v in and fuse is ok but no power anywhere else.
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Hi All,
I have a Yamaha A-520 that has no sound output.
I notice after power up the protection protection relay does not click in.
I'd appreciate any pointers on where to start.
Many thanks.
Service Manual below:
https://www.badcaps.net/forum/attach...1&d=1641841819... -
Hi everyone,
Brought a non functionnal PS5. Apparently only a bad PSU...
No beep, nothing.
After some tests i found this :
- PSU is fine (12 volts stable)
- 12 volts line is shorted
- DA9065 was fried, F7003 also => Replaced both of them, short is gone on 12 volts line, no dead short anywhere else.
- By the way, nothing change. No signal, no power, no beep.
Mesuring all rails with my workbench psu (12 volts input)
- 0.00 amp drawing
- 12 volts, 5 volts, 2 volts, 1,15 volts are presents (suppose new DA9065 do is... -
Good day to all. The bite alarm drains 9-volt Krona batteries. Current consumption when switched on is about 50 mA. I wiped the board from oxides, I will attach a photo (on the board there is a j3y transistor and a 7533 stabilizer, the microcircuit is erased = (the 3.3-volt stabilizer heats up weakly. I replaced it, nothing changed. I unsoldered the microcircuit, the consumption disappeared. The resistance on the pins of the unsoldered microcircuit from the point clockwise is more than 2 megaohms, the 11th leg is presumably ground. I warmed up the microcircuit, the consumption does not change....
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Hello,
Dell Latitude 5420 P137G
Board: LA-K491P REV A01
I have received this laptop which was described as "does not power on or accept charge." Battery shows no sign of charging when charger is plugged in, nor does the board show any signs of life when battery is unplugged and charger is plugged in. No light from the LED at all or any other indications of activity.
Board seems to have no shorts, all power rails are fine and show high resistance.
When charger is plugged in, voltage is present in 3.3V rail but absent in others....
Comment