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  1. kellys_eye

    Unknown capacitor.

    Another look at it and I'm convinced it's what I say except the 'I' is actually a 'J' (tolerance code). There's no way you can drop AC mains to anything 'comfortable' without a capacitor in the 100's nF range. Besides, I've never seen a (relatively) low volage capacitor of that type, in that...
  2. kellys_eye

    Unknown capacitor.

    Looks to me like the capacitor reads μ68 I 250 F1 (could be 350, not 250) - either way the 250/350 is the voltage rating. I would assume your local supply is 120V with a 250V rated capacitor - seems a bit close to the knuckle for a 240V AC mains......
  3. kellys_eye

    Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B

    Not directly..... Steve points you in the right direction though. Getting a decent load for that unit at full power won't be easy nor will it be 'safe' unless you take adequate precautions. Fire is only ONE issue you're faced with. A load of domestic filament light bulbs wired series/parallel...
  4. kellys_eye

    Problem with Clamp Meter (Benning)

    Did you insert the batteries correctly? Sure they are new/charged? The circled connections are for the clamp. Looks to me as if there is corrosion between some of the processor pins. There's also a dodgy soldered link beside the red connector - potentially indicating the track 'blew out'...
  5. kellys_eye

    Arcade Conversion... Dollars to Nickles

    Use a test meter to measure the voltage on pins 7&8 to determine that there is NONE WHATSOEVER on them under any circumstances. Alternatively use the meter on it's continuity range and check that pins 7&8 short together briefly as a coin is inserted. If there is zero voltage on 7&8 then put...
  6. kellys_eye

    Unknown capacitor.

    That capacitor looks to be marked u68 = μ68 = 680nF and therefore correct on the meter. 680nF is consistent with the value necessary to drop the volts and is a standard value - unlike 6.5nF. Where they use zeners to regulate voltage they often under rate them (dissipation-wise) and they fail...
  7. kellys_eye

    Woo-Woo Is it possible to attenuate a signal not at the source

    You mean those totally fraudulent products made to relieve the gullible of their cash? Get yourself clued up before they take a single cent from you.
  8. kellys_eye

    Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B

    600V into 5.5ohms is 100amps! The PSU would cut out (safety cutout, current overload) well before that was reached. To load it to its maximum you would need to put the 600V across a 133ohm resistor.
  9. kellys_eye

    I need help to make sure the devices are good to go.

    That was a guess based on the old xbox360 however I see that a modern games machine like the PS4 consume half that so around 120 watts. This makes the average for TV and games at around only 1 amp.... tiny!
  10. kellys_eye

    Tower electric fan starts and stops continuously

    All those devices are probably small triacs or thyristors - try to get the part number from the side of them and Google it. The area in the picture below is the capacitor dropper circuit where the DC output is across ZD1 - this can be measured using your test meter. Take care as there is live...
  11. kellys_eye

    schematic for class B Viking B

    Sounds like one from an old UPS device? Is that the case? Can you post pictures of it?
  12. kellys_eye

    Softeen 500W Led Fog Machine with Lights, circuit board has melted and I need help identifying it

    I can see that the device closest to the burned area is a bridge rectifier. Looks to have been a small SMPS to provide a voltage for the rest of the circuit and the smoothing capacitor looks to have arced over, burning the board area. I'd guess that C1 is rated at 400V (if that's a board...
  13. kellys_eye

    Tower electric fan starts and stops continuously

    Could be me bit TR1 and (possibly) TR4 look to be physically damaged - can't really tell from the pictures. Maybe you can determine this yourself?
  14. kellys_eye

    Detect AC Power supply

    The current range for LED operation can vary considerably yet still allow it to work. Take the average AC voltage (220V) and use that to calculate the required resistor for 5mA current flow. Any changes either side of that will be acceptable. Alternatively take the 230V as the 'working value'...
  15. kellys_eye

    I need help to make sure the devices are good to go.

    Those markings indicate the maximum amount of power that the adapter can carry. As above, most modern LCD TV's take around 80-150W and the PS4 maybe 300W (max) so the total power consumption for the two would be around 500W total which is around 2A at 240V.
  16. kellys_eye

    LED TV half screen is white

    Only by straight swapping. You may also have an issue with the ribbon to the actual LCD panel - there are column driver devices on a flexible ribbon between the TCON board and the LCD panel itself and the flexi ribbon sometimes comes away from the LCD panel edge itself and is NOT fixable. It...
  17. kellys_eye

    LED TV half screen is white

    Possible fault on the TCON board - small board that attaches to the LCD column drivers, usually at the top of the set (inside, behind the cover of course). Usually available online. May even be a simple ribbon cable misalignment. Time to take the back cover off.
  18. kellys_eye

    Detect AC Power supply

    With 100k resistors I'm surprised you're getting anything at all. This means only 0.5mA through the opto's LEDs. Without referring to the data sheet (coz I can't be bothered to download one) is <1mA sufficient to activate the LEDs?
  19. kellys_eye

    Softeen 500W Led Fog Machine with Lights, circuit board has melted and I need help identifying it

    Picture size - there are limits to what can be displayed on this forum. Use an image editor to resize pictures to 1024x768 or 800x600.
  20. kellys_eye

    Realistic STA-2100D

    'Act funny' isn't a technical term I recognise. References to part numbers isn't very useful when we don't have a schematic to compare to. Post the schematic and any pictures of the circuit boards you have.
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