Power issue with Yamaha receiver

anamitram

New Member
Joined
Aug 17, 2022
Messages
3
Points
1
Location
Germany
Hi everyone!

So my setup is like this.
Amplifier : Yamaha RX V479
Sufwoofer : Klipsch R12SW
Speakers : Klipsch 4+1

Challenge1 (background, partially solved)
Due to an incorrect handling by my moving company my subwoofer cable pin had broken down. This I did not realise till I found that no sound was coming from my sufwoofer and when I tried to touch the gain switch I received a massive shock (which I will remember for my life). I later switched off the mains and saw that the pin had broken which was clearly camouflaged by my moving company. I later took out the pin which was stuck inside which was leading to the current leakage. A new subwoofer connection cable was ordered and it fixed the problem.

Challenge 2 (leading to a new issue)
While the setup was working fine, I now saw a residual current getting generated on my amplifier Yamaha RX V479. It wasn’t a massive current but my electric tester could detect it. The power was getting leaked to my connected subwoofer as well as the TV. Most metallic touch points had a power leakage now. An expert from the Yamaha dealer came and checked the system. Said it’s an inherent Yamaha problem and won’t cause damage. Said he could earth the system which will resolve it but advised wont be necessary. I decided not to do it. The system has been running since a year without a problem.

Challenge 3 (pressing issue now)
The Yamaha amp now died. Red light blinks to protect the system. Fails to boot up showing the A1-1 DSP Pass through error. A force boot further detects an issue with PS2 PRT133 error message and goes on standby. This I understand is an issue with the power supply. The amplifier is now given to an authorised Yamaha dealer for a complete check and repair

My ask:
How can I check and exclude the fact that the subwoofer is not the culprit? Assuming that the Yamaha receiver now comes back fully repaired (at a huge cost :( I know) how do I convince myself that the subwoofer is not at fault, given the fact that it all started with the broken stuck pin inside eve subwoofer, which led to the power leakage everywhere, and might have damaged the amp? I don’t have a good dealer around who can do a test of the speakers, and was wondering if I can check the subwoofer with a multimeter or something? Some basic Home checks with the power on / off? Really looking forward to some ‘homely suggestions’. To be direct and honest, getting it checked by an expert is not an option unfortunately.

Sorry my post was detailed but wanted to give the sequence of events in case that rings some bells. Thank you very much!
 
Last edited:

mbhangui

Well-Known Member
Joined
Jun 25, 2011
Messages
1,565
Points
113
Location
Pune
You will have to locate the service manual for your receiver, download it and see what does PS2 monitor. Each Yamaha model the PS1, PS2, PS3 protection codes are different.

e.g. for RX-V483 it is

PS1: AC_BL, AC_12, ±7A, +3.3S
PS2: ±12A, +5A, +5VID, +3.3T, +41F
PS3: +5.5V

Normal value
PS1: 29 to 118
PS2: 135 to 191
PS3: 132 to 168

The DSP chips usually run on 3.3 v. Your error is PRT 133 which corresponds to 1.71 volts. Now 1.33 gets supplied by the SMPS board. These Yamaha and (other AVR) SMPS boards. The IC on these ports is usually TOP 25x. The max voltage these IC go to is 375v DC. India has suddenly changed it's voltage standards. It used to be 230 +- 5%. Now it is 240v +- 10%. So the max AC voltage is now 256v. I have observed this voltage at least at Pune. Behind your AVR near the power cord it must be written 110v - 240v. When 256v gets rectifed to DC it is 374.710 (peak RMS value is AC voltage multiplied by square root of 2). So it is highly likely that your SMPS board IC has got damaged due to high voltage. I guess you are using this AVR without a voltage stabilizer. But I also see you are in Germany. You cannot have this wide voltage tolerance in Germany. So I guess that the IC just went bad. These ICs cost just around Rs 60. The official Yamaha service was quoting more than RS 9000 + labour + GST to fix this.

I had a similar issue. My Digital HDMI board was getting less voltage and it used to go into proction mode in few minutes (and later on the AVR remained on just for few seconds). Opening the board I found the SMPS IC TOP254PN heating up terribly.


Others too

Regarding the tester glowing, don't bother so much. You will have this tester glowing with all equpments having SMPS. The current is negligible. For peace of mind, get yourself a digital multimeter. They don't cost much now. Measure the residual ac voltage between AVR body and an earth pin in the power socket.
 
Last edited:

anamitram

New Member
Joined
Aug 17, 2022
Messages
3
Points
1
Location
Germany
You will have to locate the service manual for your receiver, download it and see what does PS2 monitor. Each Yamaha model the PS1, PS2, PS3 protection codes are different.

e.g. for RX-V483 it is

PS1: AC_BL, AC_12, ±7A, +3.3S
PS2: ±12A, +5A, +5VID, +3.3T, +41F
PS3: +5.5V

Normal value
PS1: 29 to 118
PS2: 135 to 191
PS3: 132 to 168

The DSP chips usually run on 3.3 v. Your error is PRT 133 which corresponds to 1.71 volts. Now 1.33 gets supplied by the SMPS board. These Yamaha and (other AVR) SMPS boards. The IC on these ports is usually TOP 25x. The max voltage these IC go to is 375v DC. India has suddenly changed it's voltage standards. It used to be 230 +- 5%. Now it is 240v +- 10%. So the max AC voltage is now 256v. I have observed this voltage at least at Pune. Behind your AVR near the power cord it must be written 110v - 240v. When 256v gets rectifed to DC it is 374.710 (peak RMS value is AC voltage multiplied by square root of 2). So it is highly likely that your SMPS board IC has got damaged due to high voltage. I guess you are using this AVR without a voltage stabilizer. But I also see you are in Germany. You cannot have this wide voltage tolerance in Germany. So I guess that the IC just went bad. These ICs cost just around Rs 60. The official Yamaha service was quoting more than RS 9000 + labour + GST to fix this.

I had a similar issue. My Digital HDMI board was getting less voltage and it used to go into proction mode in few minutes (and later on the AVR remained on just for few seconds). Opening the board I found the SMPS IC TOP254PN heating up terribly.


Others too

Regarding the tester glowing, don't bother so much. You will have this tester glowing with all equpments having SMPS. The current is negligible. For peace of mind, get yourself a digital multimeter. They don't cost much now. Measure the residual ac voltage between AVR body and an earth pin in the power socket.
That is so helpful! Thank you so much! Yes the problem started after I moved from mumbai to Frankfurt. One day it worked perfectly fine. The next day the system died :(
 

mbhangui

Well-Known Member
Joined
Jun 25, 2011
Messages
1,565
Points
113
Location
Pune
That is so helpful! Thank you so much! Yes the problem started after I moved from mumbai to Frankfurt. One day it worked perfectly fine. The next day the system died :(
I think the SMPS board went faulty in Mumbai itself. But the DC regulation has gone bad becuase of the TOPxxx IC, or reference voltage chip TL431 chip or an electolytic capacitor gone bad. The slightly lower voltage in Germany (exact 230v compared to > 240v in mumbai) is causing lower voltage being delivered (1.71 volts instead of 3.3 volts) to the digital boards. The protection is kicking in because of the lower voltage. I guess the service centre will replace the entire SMPS board. It is one of the smaller boards and hopefully it won't be very expensive.
 

anamitram

New Member
Joined
Aug 17, 2022
Messages
3
Points
1
Location
Germany
I think the SMPS board went faulty in Mumbai itself. But the DC regulation has gone bad becuase of the TOPxxx IC, or reference voltage chip TL431 chip or an electolytic capacitor gone bad. The slightly lower voltage in Germany (exact 230v compared to > 240v in mumbai) is causing lower voltage being delivered (1.71 volts instead of 3.3 volts) to the digital boards. The protection is kicking in because of the lower voltage. I guess the service centre will replace the entire SMPS board. It is one of the smaller boards and hopefully it won't be very expensive.
Update: Yamaha said the motherboard has fried up and the repair cost is 390 euros! Better get a new system? :(
 
Perfect for audiophiles wanting both excellent music quality and flexible operation.
Top