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Yamaha RX-V475 not working

Discussion in 'Troubleshooting and Repair' started by raczq, Jun 22, 2017.

  1. raczq

    raczq

    5
    0
    Jun 22, 2017
    Hi all.

    I have an amplifier that does not want to turn on. Power LED is off. When i press Power button then few relays is clicking.
    VFD shows "Mains ON" and then notking. VFD is blinking.
    Please check video.
    I have the service manual and i check a few voltage on power supply. 5,5VDC and 3,3VDC is good.

    Forgive me for my english.
     

    Attached Files:

  2. 73's de Edd

    73's de Edd

    2,696
    1,092
    Aug 21, 2015
    Sir raczq . . . . .


    The unit just might have found a fault . . . and it possibly only having been intermittent in nature . . . .yet, the unit had gone into auto-protect mode.

    Check out that possibility by powering up and seeing if your problem still exists. If so:

    Then you find INFO and TONE pushbuttons on the front panel and press them down simultaneously and hold then down and start a slow 1-10 count. At some time you should hear a relays click.

    Power up the unit again and see if things are back to normal.

    If not . . . .troubleshooting is ahead.


    Go to . . . . . . . Then click on to mag up

    http://avgear.ca/eBay Images/RXV475/RXV475_Front_LG.jpg


    73’s de Edd
     
  3. raczq

    raczq

    5
    0
    Jun 22, 2017
    Hi ! The display shows "NO PROTECT" and is still blinking.
    In standby LED is still off... When i start the reciver power LED is stil off.
    I think is missing some voltage in power supply but i check this and is OK.
     
    Last edited: Jun 23, 2017
  4. raczq

    raczq

    5
    0
    Jun 22, 2017
    On IC541 in Vcc i have to high voltage.
     

    Attached Files:

  5. 73's de Edd

    73's de Edd

    2,696
    1,092
    Aug 21, 2015
    Sir raczq . . . . .

    You did not quantify by how much . . . . . therefore . . . most importantly, what does the voltage output from this supply show .

    Hopefully right at 5.6 VDC and without any ac ripple and it is not fluctuating up and down ?

    RELEVANT REFERENCE:
    YAMAHA 475 SM Power Supply.jpg




    73's de Edd
     
    Richard9025 likes this.
  6. raczq

    raczq

    5
    0
    Jun 22, 2017
    Output of this supply is 5,6VDC and is correct.

    About IC541 Vcc on pin 2 is 16,8Vdc but in pin 4 i have 0,96Vdc.
     
  7. raczq

    raczq

    5
    0
    Jun 22, 2017
    I check this site of power supply. Check the attachment.

    in check point TH541 i have 320V ! and at D5401 on AC i have 230V.
     

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  8. 73's de Edd

    73's de Edd

    2,696
    1,092
    Aug 21, 2015
    Sir raczq . . . . .

    You have picked a section of the TV that is using a switch mode power supply.

    It so happens that both of us are using the same schematic which shows a markup of voltage values while using 120VAC input. In Poland you are using twice that voltage input.

    If you look at the bridge rectifier they are using two different part numbers relevant to the two different operating power voltages.

    Also, at the C5407 main raw dc filter capacitor, over to the right you will see two different specifications in accordance to AC power input at 120 V they are using a 220uf cap at 220V while the 230 volt input is using only a 150 ufd cap but rated at 400VDC.
    (The arrowed on designation of a 5K10w wire wound resistor across the main filter capacitor is just prompting you to use that item for bleeding down the supply after unplugging and getting ready to work in that section.)

    You have no problems in that “hot” circuitry at the left of the central divisional dotted line.

    On the right side of the circuitry, which is being line voltage isolated , by the secondary windings of the TS401 power transformer, you have the proper 5 and 3.3 volt DC supplies outputted, IF there is no appreciable ripple voltage present on them.

    The systems other principal supplies are linear supplies that are using the power transformer that you are seeing been fed from your same 230VAC line up the two VHIS and CB544 supply lines over to the right.


    73’s de Edd
     
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