Yamaha RX-V667 PS2 fault - Page 1
Forum section: electronics / repair

author: Fity
author_rank: Newbie
timestamp: December 03, 2015, 02:07:32 am
content: Hi all, I am having trouble repairing my Yamaha RX-V667. It initially shut down due to an over current fault which turned out to be a short on a channel (blown transistors etc) and would not go into self diagnostic mode. I repaired the channel and now it turns on for 1 second and turns off. I can now get into self diagnostic mode OK and I can read the fault which is "PS2 PRT 182H", a voltage problem on the power supply. The service manual states that PS2 monitors +5I and -5V and the normal ADC value should be 90 / 88. In diagnostic mode it displays PS2: 112 / 182.Another thing that I notice is that the voltages out of the transformer are OK, but after they go through the relay on the main board (not the main power relay) they are around double what they should be.Can anyone shed some light as to where to start looking?Thanks for any input.

author: Fity
author_rank: Newbie
timestamp: December 03, 2015, 05:13:38 am
content: Forget what I mentioned about the transformer voltages, it was a wrong test point on my end.

author: mzacharias
author_rank: Frequent Contributor
timestamp: December 03, 2015, 04:11:52 pm
content: Have you checked that the PS2_PRT line is near 1.2 volts?

author: Fity
author_rank: Newbie
timestamp: December 03, 2015, 11:06:01 pm
content: Thanks for the reply mzacharias,I have measured PS2_PRT and am getting 2.3 volts.Am I correct in thinking that the fault message of "PS2 PRT 182H" suggests that 182 after the ADC calculation (3.3v = 255) = 2.3 volts?I have measured +5I and I am getting ~0.8vAC. Is that possible?

author: mzacharias
author_rank: Frequent Contributor
timestamp: December 04, 2015, 07:56:41 pm
content: I don't think that AC should be there - have you looked at that line with a 'scope?Quote from: Fity on December 03, 2015, 11:06:01 pm

author: Fity
author_rank: Newbie
timestamp: December 06, 2015, 12:48:44 am
content: Yes. On the scope it is a sine wave with ripple oscillating at 50hz.I keep reading about a common capacitor problem in the power supplies on yamaha receivers. C405, my unit doesn't have a C405 cap anywhere.

author: Fity
author_rank: Newbie
timestamp: December 08, 2015, 05:02:53 am
content: A bit more info on the +5I line. After crawling the schematic for hours I have found that my model of RX-V667 does not have a +5I power supply fitted, the schematic has a cross through the regulator chip labelled "no_use" and the regulator chip is not on the board. However the diode bridge and a few components are there.Now to explore the -5V line.

author: jwfirebird
author_rank: Newbie
timestamp: December 09, 2015, 12:45:03 am
content: hoping you find the fault and post it

author: jwfirebird
author_rank: Newbie
timestamp: December 09, 2015, 04:18:21 pm
content: i measured the c3701, c3717 on video 2 (ps card to most)(the little brown ones that look like the common bad ones on youtube). they were .021u and the man says .022 so they are good i think. think i am going to put it back on ebay and get my money back, doesnt seem like i am going to get any further with it. i am sure others have figured it out there are a number of them on ebay but those people probably dont want to put it on the net so they wont make any money.

author: Fity
author_rank: Newbie
timestamp: December 10, 2015, 04:56:40 am
content: I think I am getting somewhere with it. The -5V supply is not working. It seems that the -5v supply requires the +5v supply to work before it can produce the -5v supply. I had to attach a wire to the +5v supply as there were no test points accessible once assembled. It seems slightly off (~5.5v on power up, then 5.1v) so I am waiting for a replacement to turn up. Hopefully this is all it needs. Then I can test the repair to the blown channel is ok.

author: jwfirebird
author_rank: Newbie
timestamp: December 11, 2015, 02:55:35 pm
content: i found IC1 on hdmi board, digital 1, hot enough to burn my finger after on in protection disable mode for a couple minutes. manual says no replacement, whole board cost is like 250-350 American which is not happening. i dont know if i am should try another 667 off ebay in the chances that one may be good or get rid of this, possibly sell the other parts out of it? my luck isnt real good, probably get one with the same board bad.

author: jwfirebird
author_rank: Newbie
timestamp: December 11, 2015, 08:22:50 pm
content: mine for sure was ic1 on the hdmi card. i de-soldered the chip and shes happily playing transformers as i type this. but the chip controls hdmi stuff and you cant use the option menu on the gui. you can change the DSP mode through the front panel though and it sounds as good as my old yamaha. still dont know what i am going to do personally wanted the adrc for commercials and the instructions say off is default and you need the gui and stock remote to turn in on.so for anyone searching it had PS PRT: 1L and all the ps levels on the service menu read one.

author: Fity
author_rank: Newbie
timestamp: December 18, 2015, 12:54:33 am
content: It's fixed!!!!The +5v regulator was the culprit.PS2_PRT monitors +5I and -5V supplies. Th RX-V667 doesn't have a +5I supply so it must have been a -5V supply problem. The -5V supply is dependent on the +5V supply. As the +5V supply was out of spec, replacing the regulator fixed the +5V supply which also enabled the -5V supply to operate correctly.It now turns on and stays on. It took many hours to get my head around the schematics and the actual PCBs, but $2 later it is all fixed.Hope this helps someone else.

author: monkmad
author_rank: Newbie
timestamp: January 16, 2017, 03:48:23 am
content: Hi,I know it's been more than a year since the last post on this thread, but can someone please tell me the name/spec of the +5V regulator, and how to test it? I have a Yamaha RX-V675 which has a PS2 151H error.My unit also doesn't have a C405 capacitor.Thanks

author: mzacharias
author_rank: Frequent Contributor
timestamp: January 17, 2017, 11:49:14 am
content: I'm not really finding any ordinary 5V regulators on this model. The voltage regulation tasks are distributed all over the various boards and consist in many cases of small switching regulator circuits.In this case I would be very suspicious of the operation(2) board and specifically the two switching regulator circuits shown providing + and - 3.3 volts and two ea. 5 volt lines, shown on the right side of page 136 of the PDF service manual.Of course, the regulators etc may be just fine - and some chip or other loading one of them down.

author: monkmad
author_rank: Newbie
timestamp: January 17, 2017, 04:56:17 pm
content: Thanks for your response, mzacharias. I'll take a look at those and see if I can find the culprit.

author: Nightrider0614
author_rank: Newbie
timestamp: February 25, 2017, 06:18:12 pm
content: Did you find the issue with you rx-v675? I am working on one with the same issue.Fortunately I have 2 with different issues. 1 had a bad hdmi and 1 in ps2 protect mode. I swapped hdmi and everything seems ok in test mode, getting ps2: 172h error. I took the operations 2 board out of the other unit and swapped with no charge so I don't think it's the regulators there.I'm usually pretty good with this stuff but this one has me stumped!

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: February 27, 2017, 08:32:59 pm
content: The Korean ALL plastic T0-220 regulators in these Yamahas are problematic...http://www.ebay.com/itm/10PCS-KIA7905PI-TO-220-1A-Three-Terminal-5V-Negative-Voltage-NEW-/172317550142?hash=item281eed263e:g:~q0AAOSwHoFXvXIRhttp://www.ebay.com/itm/5-Pieces-KIA7805PI-Voltage-Regulator-5V-1A-Replacement-NTE1960-Positive-5V-/272339389788?hash=item3f68b14d5c:g:A2oAAOSwgZ1XrhdM

author: Satbeginner
author_rank: Regular Contributor
timestamp: November 01, 2018, 01:45:59 pm
content: Hi all, I know this is an old thread, but it helped me repairing my RX V663.Mine switch on, but of after one second it would switch off again.Pressing and holding 'straight' and 'audio select' followed by pressing POwer On worked as some kind of override, so it would show me an 'PS2 PRT' error.Using 'INFO' and 'TONE' combined brought me in an 'Advanced Setup', where test no. 8 would show a PS1 of 145 (OK, it's within the 110-255 limit),but the PS2 value was L077, so I assume Low with a value of 77.The limits for this test are 88-140, as shown on page 47 of the service manual.It turned out to be an all plastic KIA 7812 positive regulator on the MAIN-2 board, I could check the voltages on connector CB303 of that little board, it's accessible from the top of the Amp, it was only 1,56VThis board is a 25 cm long and 3cm wide board, attached to the main cooling body in the center of the Amp.With some fiddling I replaced IC104 (7812 regulator) with a 1.5Amp version that had a metal cooling tab as well.I did put insulation between it to be sure, since the original had a plastic housing, so I did not want to create an unwanted ground loop of some sort.After the replacement the 12V came back as normal.After that I had to perform a full reset by going to step 23 of the Advanced Setup menu.Turn the knob to select 23, then press one of the 4 audio field select buttons, it will show Preset RSRV.Now power off the Amp, all done.Un saludo,Leo