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  1. kellys_eye

    Modified wiring, your thoughts?

    You should have insulation over the bare earth wire otherwise it looks ok to me.
  2. kellys_eye

    Removing Components for Testing versus On Board Testing

    I'm afraid it your own ignorance that is, as we progress this thread, showing itself to be very apparent. All subjects require learning of some sort. To achieve 'anything' you need to either have knowledge of it or be shown, step-by-step, how to do it. There is a HUGE difference. Simply...
  3. kellys_eye

    Converting frequency on US devices (60Hz - 50Hz)

    I call BS on that statement. Either its a conventional motor (which would either work with 'any' frequency or run slower if the motor is the frequency-dependent type) or it's a 'digital' motor in which case the frequency is totally irrelevant as it will be driven electronically. My impression...
  4. kellys_eye

    Faulty Inverter Board

    Since they are wired in parallel (grouped) testing 'one' means testing them all so a short - easily found using a test meter - would necessitate removing that 'bank' of MOSFETs to test them individually to identify the culprit.
  5. kellys_eye

    Trying to identify what these are

    Yep.
  6. kellys_eye

    Faulty Inverter Board

    Is this an on-line or off-line inverter? An offline version will 'pass through' the connected AC whenever it is connected to an AC source and only switch to AC out (via inverter) in event of AC input loss. The online version uses the connected AC to charge batteries and run the inverter...
  7. kellys_eye

    Faulty Inverter Board

    I suspect the output MOSFETs blew because you initially connected the battery input cables in reverse. Not only would this damage the MOSFETs it could well have shorted any reverse-polarity protection diode - they usually fail short-circuit. The replacement devices have nothing to do with the...
  8. kellys_eye

    I am seeking a builder person/friend. I'm a project manager in my head.

    I knew what Gallium Nitride was - the 'e' bit threw me..... Given that all you're talking about is 'basic' power switching albeit with faster/more powerful devices I don't see what's so special about the possible deign of 'power conversion' type circuit.... any capable power circuit designer...
  9. kellys_eye

    I need help with fixing a Sega Mega Drive 2 controller

    If you can't see any physical breaks in the track then the only conclusion is that the onboard chip (under that black blob) is dud in some way. It's not repairable. Double-check for breaks and clean the pins on the edge of the board as I can see a solder drop between two of them. That won't...
  10. kellys_eye

    Help Please with a monitor PSU.

    The 5V supply comes from its own transformer secondary but the 12V comes from a HIGHER voltage supply (the other secondary winding) via a regulator. This 'higher' (unregulated) voltage is what? 24V? What does it measure as you first power up or are turning the power on? Does it fall? With...
  11. kellys_eye

    Please Help - Massage chair mainboard failure?

    No, a reset won't wipe the chip but it likely won't do anything else anyway as the 'reset' function is implemented every time the equipment powers up.
  12. kellys_eye

    Converting frequency on US devices (60Hz - 50Hz)

    You should use a work site isolation transformer (230-to-115V) to get the right voltage. You'll have to live with the frequency difference which will manifest itself as a slightly slower motor speed (depends on the type of motor actually). If you can separate the motor from the heater elements...
  13. kellys_eye

    I need help with fixing a Sega Mega Drive 2 controller

    What you don't show are the conductive rubber pads under he buttons themselves that form the path for the 'switch' current to flow and thus work. Is the pad there? Is it clean? You can temporarily short the 'dud' tracks with another pad to prove the pad works with the track.
  14. kellys_eye

    Please Help - Massage chair mainboard failure?

    If the main processor supply is ok then you might have a dud CPU. Unless you can prove CPU operation you're pretty much fiddling at the edges chasing 'faults' that may only as a result of the CPU not working.
  15. kellys_eye

    I am seeking a builder person/friend. I'm a project manager in my head.

    What is "eGaN"?
  16. kellys_eye

    Help Please with a monitor PSU.

    In value maybe - did you check for ESR? The SMPS secondary seems to have two separate outputs - one delivering the +5V and the other some 'higher' voltage for the backlight and +12V (via a regulator). The supply to the inverters goes via F1 (beside T2) where F1 is actually a wire link...
  17. kellys_eye

    Learning Electronics for Everyday Practical Reasons Non-Professional

    Don't bother with an oscilloscope until you have the very basics of fault diagnosis down 'pat'. An oscilloscope won't make a blind bit of difference if you don't understand the circuit you're working on, how it works and can localise the area that might be at fault. You can do all that with a...
  18. kellys_eye

    Removing Components for Testing versus On Board Testing

    That's not the way it works. You should be able to determine - to some extent - what area of a circuit is at fault and, from a few multimeter measurements, localise that to one or two potential items of interest. That's the point at which you either release one end of a component or remove it...
  19. kellys_eye

    Help Please with a monitor PSU.

    Power cycling is indicative of problems in the power supply circuitry and, in your case, obviously the backlight circuitry. Find the backlight board power connector and disconnect it - see if the monitor starts up 'properly' (although you won't see any image) and if it does then check the...
  20. kellys_eye

    Pioneer RX-570

    Post clear pics of the unit and the area of concern. @tunzafun001 probably referring to the output semiconductors (MOSFETs) that are both soldered to the main board and bolted to large heatsinks. If the unit was disturbed (banged) in transit then the weight of the heatsink may have dislodged...
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