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I have built a preamplifier with a regulated power supply. It uses a 7815 regulator on the positve rail and a 7915 on the negative. The problem is that frequently at switch on, no poistive voltage appears at the output of the 7815 although there is voltage at the input. I have replaced the 7815 and all the components that it supplies. The problem occurs about 50% of the time. The negative rail is okay. Any ideas? Thank you. Joe Pickering

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Check for cold solder joints at the 7815. these cause shorted and burned out components or not voltage or current flow.

Posted on Apr 24, 2010

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I have a old denon avr-1804. try to switch on power but can not. just appear a main power red light flashed rapidlly. please tell me why?


Greetings
the red flashing LED is that the Device is in protection mode.
the internal power supply . +15 volts and -15 volts are defected you need to be replace it ... Regulators 7915 and 7815 .... these you should change , might also need to check capacitors .
these are common defects for Denon . AVR units.
Good Luck
Hope this helps

May 26, 2016 | Denon Audio Players & Recorders

1 Answer

Mixing board had all the lights come on at once and no sound


Hi,

Despite the mixer's namebrand i can say that should be a low voltage supply issue, mixers have normally just 3 voltages, and the ones with effects 4, the critical voltages that mantain a mixing board working are just 2, +15V and -15V and you can check for them at Pin4 for -15V and pin8 for +15v of operational ic's at any channel with the mixer on, one of those are not present and this is you issue for sure, certain mixers have fuses for this two voltages but since you are not posting the namebrand i can't figure it out, if one voltage is missing could be the fuse or the power regulator that reads"MC7825" or "MC7915" which 7815 is for the positive rail and 7915 for the negative one, both are located in the power supply board, let me know more to help you more.

Oct 05, 2013 | Music

2 Answers

I have a Behringer zenyx 2442fx mixer. I was using it one day and all the LEDs started glowing brighter and brighter until the whole desk went dead. It has not worked since. I'm guessing the power...


That sounds bad! I haven't heard of a runaway supply for these... Testing of the power supply is in order. The LED's are all driven from the +15 volt supply which is secondary regulated by a three terminal regulator... probably a 7815. I have seen failures of this chip in another Behringer product so it may be a bad batch. The question now is if this has fried the main switching power supply.

Nov 02, 2011 | Behringer XENYX 2442FX Mixer

1 Answer

I am wondering where the -15V regulator (7915) is located in the avr-788. I am trying to replace it.


on a heatsink in power supply board. the small board between power transformer and back plate.

Aug 04, 2011 | Denon Audio Players & Recorders

1 Answer

Im gonna rplace the fuel pressure regulator. In the haynes manuel it says that you need to remove the fuel rail. Ive asked a few people and they said they dont think it is necassary it is an 03 impala. ...


Not sure why Haynes says to do that. below is instructions from autozone.com, and none of the engines require the fuel rail to come off. That said, if you have the 3.4, you may need to pull the upper intake manifold.


Removal & Installation The need to work as cleanly as possible cannot be over-emphasized. Even the smallest amount of dirt, if allowed into the fuel pressure regulator and/or the fuel rail, will find its way to the fuel injectors. The nozzle openings of the injectors are very small. Keep hands and tools clean. Clean the areas to be disconnected with a suitable solvent. Carefully cover open fittings and connections to keep out foreign material. Dirt in the injectors almost guarantees a clogged fuel injector and engine performance problems.

3.4L (VIN E) Engines

  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure.
  3. Remove the upper intake manifold assembly.
  4. Disconnect the vacuum line from the pressure regulator.
  5. Remove the regulator retaining screw and remove the retainer bracket. Using a clean shop cloth to catch fuel spillage, carefully pull the regulator from the fuel rail. Twist the regulator slightly while removing to ease removal. Discard the O-ring.

    0996b43f802307fd.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. Exploded view of the fuel pressure regulator mounting-3.4L (VIN E) engines


To install:
  1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
  2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
  3. Lubricate a new pressure regulator O-ring with clean engine oil and install on the regulator inlet.
  4. Install the fuel return pipe to the regulator.
  5. Install a new retainer and spacer bracket into the slot on the fuel rail and install the pressure regulator to the fuel rail. Tighten the fuel return line nut to 13 ft. lbs. (17 Nm).
  6. Connect the vacuum line to the pressure regulator and install the retainer screw. Tighten to 76 inch lbs. (8.5 Nm).
  7. Inspect and verify that the retainer and spacer bracket is engaged in the slots in the fuel rail. Grasp and pull on the regulator to ensure that it is properly seated.
  8. Install the upper intake manifold.
  9. Connect the negative battery cable.
  10. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2. Turn the ignition switch to the OFF position for 10 seconds.
    3. Turn the ignition switch to the ON position again.
    4. Inspect all areas for fuel leaks.

3.8L Engines
  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure.
  3. Clean any dirt from the fuel pressure regulator retaining ring.
  4. Remove the vacuum hose from the pressure regulator.
  5. Remove the snaprings. Twist the regulator slightly and pull the pressure regulator from the fuel rail. Use a shop towel to catch fuel spillage as the regulator is removed.
  6. Remove the O-rings and O-ring back-up.

To install:
  1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
  2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
  3. Lubricate the new pressure regulator O-rings with clean engine oil. Install the O-ring back-up, the large O-ring and then the small O-ring. Install the pressure regulator and secure with the snapring.
  4. Attach the vacuum hose.
  5. Connect the negative battery cable.
  6. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2. Turn the ignition switch to the OFF position for 10 seconds.
    3. Turn the ignition switch to the ON position again.
    4. Inspect all areas for fuel leaks.

  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure.
  3. Clean any dirt from the fuel pressure regulator retaining ring.
  4. Remove the vacuum hose from the pressure regulator.
  5. Remove the snaprings. Twist the regulator slightly and pull the pressure regulator from the fuel rail. Use a shop towel to catch fuel spillage as the regulator is removed.
  6. Remove the O-rings and O-ring back-up.

To install:
  1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
  2. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
  3. Lubricate the new pressure regulator O-rings with clean engine oil. Install the O-ring back-up, the large O-ring and then the small O-ring. Install the pressure regulator and secure with the snapring.
  4. Attach the vacuum hose.
  5. Connect the negative battery cable.
  6. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2. Turn the ignition switch to the OFF position for 10 seconds.
    3. Turn the ignition switch to the ON position again.
    4. Inspect all areas for fuel leaks.

Mar 16, 2011 | 2003 Chevrolet Impala

1 Answer

Do you know what regulator/ rectifiers are used and their numerical values so i can repair my fried pv 2600 these are the row along heat sink small black ones 2 pin and 3 pin cheers


7815 and 7915 plus and minus regulators specifically. Diodes fr the 15 supplies are 1N4001 but you can use 1N4007 or anything in between.

Big power rectifiers are 2504's... which are probably 25 amp 400 volt modules.

Jul 18, 2010 | Peavey Pv 2600 Power Amplifier

1 Answer

Behringer mixer power goes off after running about 5 0r 10 minutes then power turns on.what is problem with the power supply board


That time lag would indicate a thermal problem.

Likely the power supply is a switching type that has some three terminal regulators after it such as 7805, 7815, 7915.

These have thermal protection in them and one may be shutting down.

Use circuit cooler to isolate the part that is shutting down.

May 20, 2010 | Behringer Xenyx 1002fx Mixer 10 Input 2...

2 Answers

For Behringer B300 where is the ic 7815 and 7915


Test the regulator chips FIRST before ANY replacement. These chips are very reliable and the problem is LIKELY elsewhere.

The 7815 and 7915 ar 15 volt three terminal regulators in TO220 style packages. Three leads. The 7815 is plus 15 and the 7915 is minus 15.

CAREFUL as the input and ground pins are in different order between the two.

FIND the specs and picture with Googling the numbers.

These chips will be soldered in AND MAY be screwed or clamped to a heatsink OR just standing up from the board.

Oct 20, 2009 | Behringer B1520 Pro Eurolive 15" 2-Way...

2 Answers

Grounding hum


60 Hz hum? May have a grounding problem. can you turn the power plug around or is it a one way plug?Any ac or dc voltage between unit and control/poweramp?Can you ground unit? Check for voltage first.

Oct 06, 2009 | Behringer FBQ6200 Home Equalizer

2 Answers

My AVR 235 stays on stand by


Hi...
That sounds like a amplifier module /section that has failed.
Do you ever get power surges at your place?

Oct 05, 2008 | Harman Kardon AVR 235 Receiver

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