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  1. kellys_eye

    lm 317 tip 3055 constant current

    ....the OP doesn't indicate the inclusion or use of a limiting resistor in the pot circuit....
  2. kellys_eye

    Which Electronic Component is this?

    ....and thank you for getting back to us with the results of your work. Not many people take the time to do this and it's very much appreciated.
  3. kellys_eye

    Do you still need thermal paste when using a silicone elastomer?

    No.
  4. kellys_eye

    lm 317 tip 3055 constant current

    Maximum input for the LM317 is 37V if I recall correctly????
  5. kellys_eye

    Positively charged "holes"?

    Personally I've always had issues with understanding the theory as it goes further 'down the rabbit hole' - the level of understanding gets incrementally more difficult the closer you look at it - which tends to leave me even more confused. As a result there comes a point at which you just...
  6. kellys_eye

    Video card repair , please help

    ...as good as. The manufacturers MIGHT give you a copy but you'd probably be the first person ever to get one! More because mosfets don't blow for no reason - there is usually another cause for their demise and that only leads to having to trace the circuit(ry). Being a multi-layered pcb the...
  7. kellys_eye

    Video card repair , please help

    You replace parts on a like-for-like basis, Googling the parts to source replacements. As long as the value and voltage match the part will work - even if it's physically different in appearance. If you have broken MOSFETs then the chances of repair are even lower. As already mentioned...
  8. kellys_eye

    Video card repair , please help

    Change all the electrolytic capacitors. If no better then change the GPU..... Without a schematic and a Digital Storage Oscilloscope you are left with 'grasping straws' hence the suggestion above. All parts are surface-mounted so expect difficulties in removing replacing the capacitors and...
  9. kellys_eye

    Suggested Ultra Thin 32" screen

    It is said that you shouldn't use a TV as a PC monitor (Google the reasons) but the reverse certainly isn't true - have you looked for a dedicated 4k PC monitor with those specs? Most TV receivers (black box) have HDMI (or better) as outputs to feed straight to a PC monitor.
  10. kellys_eye

    (1973) Imperial HIFI 2700 stereo decoder and memories

    The voltage at the base of the transistor is also limited by the clamping diode beside the transistor which is why it never rises past 700mV. The lamp current of 80-odd mA fits with the spec (they were never made that accurately anyway).
  11. kellys_eye

    Video card repair , please help

    Your screen cap shows that you have the card fitted and, seemingly, working..... how else would you have a screen display otherwise? The alternative is that you've fitted the card but you've not disabled the built-in graphics so the PC isn't able to access it. But purchasing a known...
  12. kellys_eye

    Electric joystick steering for boat???

    You need to determine the force requirement for the individual rams/servos before proceeding. I'm not entirely familiar with the calculations to determine this but it is imperative you get it right! Servos can work CW/CCW at will and there are many ways to enable the required movement - from...
  13. kellys_eye

    (1973) Imperial HIFI 2700 stereo decoder and memories

    T304 dud
  14. kellys_eye

    Electric joystick steering for boat???

    Blimey - you don't want much do you!!!! The whole project is a quite complicated task. Sure you're up for it (and the attendant costs)? First thing to do is fit electrically operable rams to allow control over mechanical movement. The you need to fit sensors to indicate the position of the...
  15. kellys_eye

    Eprom available?

    Some programmers come with 40-pin ZIF sockets that allow for 'any' type of chip to be inserted (up to the 40-pins that is...) which I find to be far more user friendly than the multi-socketed device that's shown.
  16. kellys_eye

    (1973) Imperial HIFI 2700 stereo decoder and memories

    0V one side (near enough.... probably a volt or less, depends on how well saturated T304 gets) and 7V DC on the other. You should, with a high impedance test meter, measure 7V DC on either side of the bulb when the bulb is off.
  17. kellys_eye

    (1973) Imperial HIFI 2700 stereo decoder and memories

    Suggests that the resistor that is common to all the switched presets (and is connected to ground) has gone open-circuit (or gone high value).
  18. kellys_eye

    Eprom available?

    'Piqued' even..... Far from it - you'll have a decent device reader/programmer that may come in very useful at a later date. I would have thought that of it was locked you wouldn't even be able to get the details of THAT fact....
  19. kellys_eye

    (1973) Imperial HIFI 2700 stereo decoder and memories

    The stereo indicator bulb operates from DC, not AC - one side of the bulb will be -ve 7V (ish) and the other side is switched to ground thru T304 to switch it on. Check for 6V AC at the pilot light bulbs and the fuse (800mA) if the pilot (scale?) lights don't work. Check for a change in...
  20. kellys_eye

    Need help Rockford fosgate 1500bd amp

    IRF2807 will work https://www.digikey.co.uk/products/en?keywords=IRF2807
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