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  1. dorke

    Do I need a new capacitor?

    Welcome to EP. It looks fine(less than 2v ripple). The question is was the power supply "fully loaded"? Any problematic phenomena with the equipment?
  2. dorke

    error code display from pulses circuit

    Like Haralad said above the thing is to identify the pause between the 2 sequences. If you are not into uC's you can build it by HW only. The circuit that will identify the pause is called "missing pulse detector". You should provide more info about the pulses:length,voltage separation time and...
  3. dorke

    Does anyone know of a good electric motor lubricant ?

    It is for an electric fan motor ,about 70W.
  4. dorke

    Lamp Replacement on Equalizer

    It is possible to tap into a low voltage DC rail and use an LED, Use a low current white or yellow LED with a series resistor. Note Alec_t words above. And the fact that you will have a different color than the Yamaha orange. Note also that a Yamaha service center near you may know the exact...
  5. dorke

    Lamp Replacement on Equalizer

    Rick, you should measure with a load . do you have any 100mA lamps? note that you can connect 2 low voltage(3V,4.5V etc.) lamps in series.
  6. dorke

    Micro USB port pulled off

    Welcome to EP. I think the best would be to contact the firm you bought it from, they may be able to repair it.
  7. dorke

    Lamp Replacement on Equalizer

    These are usually AC lamps 6.3VAC or 8VAC ,current may be around 100mA Put your meter to work and measure the voltage. It can be replaced by a LED but you need to rectify the ACV first.
  8. dorke

    Can someone help me ID 2 components pleased?

    The difference is that D1 and the cap rectify the AC to produce DC on the cap. You can connect the DC power supply (with D1 disconnected) directly to the cathode pad of D1(positive of PS) and gnd. Limit it, to say 200mA and check what you get:4volts at VR1 pin2,working board?
  9. dorke

    Suggest some better MOSFETs than IRFP260

    Both IRF250 and IRF540 are not good as replacements. You may try: IRFB4229PBF IRFPS40N50LPBF Get them from a good source ,not Ebay and the likes,you will probably get fakes!
  10. dorke

    Can someone help me ID 2 components pleased?

    Ahhh, Well if you are lucky that didn't fry the all board. I would ohm the board as per #14. And than try to operate it with an external power supply(current limited!) of 12VDC connected between the cathode of D1 pad (positive) and GND.
  11. dorke

    Cell phone call routing

    "I type in www.electronicspoint.com how does my computer know which other computer to talk to? Probably something similar? Does this process have a name?" Yes this process has a name, it is called the Internet Protocol (IP) you can start here. When you type a site name in your browser. The...
  12. dorke

    Can someone help me ID 2 components pleased?

    Output voltage of VR1 is set to 4.0V. Dropping the voltage of D3 will get it down to 3.3V,that makes sense. If the input is 12VAC than D1 is most probably a Si rectifier diode. You have a half wave rectifier with the 470uF cap. The fact that D1 and L1 are blown means high current through...
  13. dorke

    Can someone help me ID 2 components pleased?

    Identifying the blown parts is one task of the repair job. Finding out why they are blown is the other. Note that diodes D1 and D3 are the same,probably series blocking diodes. By measuring D3 you can find out if it is a Si-rectifier or Schottky diode. The LM317L output voltage at pin2 (about...
  14. dorke

    Yamaha rx-v596rds

    Here is the boot diagnostic procedure of the 596: Try it,it will give you a clue.
  15. dorke

    Voltage Controlled Voltage Source (VCVS) - Piezo Buzzer

    This isn't a "simple buzzer". It is classified as a "Medical Alarm",it has a full length tune and repetition rate. You can hear the tune on this page. In the application information (pages 9-10) it is explained how to get the 4 states you need "Off,Low,Mid,High", simple enough.
  16. dorke

    Voltage Controlled Voltage Source (VCVS) - Piezo Buzzer

    Welcome to EP. What specific Piezo Buzzer are you using?
  17. dorke

    HP 400F AC voltmeter

    You do need to short the input terminals together, i.e. Vin=0, the lower the input range the more important that is! Do that with the shortest possible wire. Still no zero?
  18. dorke

    I need a detailed Analysis on this circuit

    I'm with Dave. If you intend to learn something,put some effort into it. Here is something for you to start from: Can you resolve the question marks in the pic below?
  19. dorke

    BNC connector

    A bit more elaborated: To carry an Electromagnetic wave signal at a specific frequency range requires the "media" to be as "smooth" as possible,as not to disturb the prorogation of the signal from one point to the other . We do this by using "wave guides",most of them are coaxial cables. The...
  20. dorke

    555 timer one shot question

    Setting repeat parameters on OS here ,might help. You can also contact Apple support with a direct question on how to do it on the iPad here
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