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  1. HellasTechn

    Ceramic capacitors substitute

    I had no idea they are in shortage...
  2. HellasTechn

    Tablet RF coaxial cable.

    Thanks ill look !
  3. HellasTechn

    Tablet RF coaxial cable.

    Something like this i guess. but even this does not have a specific name. its custom made. http://www.wellshow.com/coax-cables/mini-coax-cable/0-81mm-coaxial-cable/
  4. HellasTechn

    Tablet RF coaxial cable.

    Hello friends, its been long since my last post but now im back with an other question. Does anyone know the type of the rf cable is used within tablets to connect the WIFI antenna with the module ? I have googled but it is as if it has no name... I need to source several meters of it for a...
  5. HellasTechn

    Resistor Value.

    And now thanks to you this case is solved ! I discovered a bad resistor (r12) as well as the opto itself was bad. R12 is connected to one lead of the opto's internal transistor. I also now have an idea about how the feedback circuit works ! THANK YOU. P.S. I can now start troubleshooting the...
  6. HellasTechn

    Resistor Value.

    With a 560 Ohm resistor the led glows at 12.3V. That is normal i guess. And the current drawn from my bench psu is 65ma. Funny thing is that when i connect the psu leads on the output of the psu board its sparking. probably due to the reverse biased diode on the output i think. By the way what...
  7. HellasTechn

    Resistor Value.

    If i understand correctly, i should remove the opto and solder the led biased just like the led inside the opto. then give 12V from my bench psu to the output to see if the led will glow. If it does then that probably means that feedback circuit is ok. yes ? I will replace R18 with a resistor...
  8. HellasTechn

    Resistor Value.

    If you mean the one (dual diode) mounted on the chassis then yes it is good. I have replaced it because the one originally on was shorted. Anyway right now it is good. I have checked all components i can see. all but the resistors around the tl431...
  9. HellasTechn

    Resistor Value.

    Should i run this test now that the prev one faield ?
  10. HellasTechn

    Resistor Value.

    So do i start looking for a new opto ?
  11. HellasTechn

    Resistor Value.

    I forgot to mention that while powered on the PSU makes a loud clicking noise. Now with the resistor removed the DMM could not give a steady reading. Withing 5 seconds or so the output capasitors get very very hot and if powered on for about 10 sec they start to pop.
  12. HellasTechn

    Resistor Value.

    The huntron tracker 2000 indicates that the led within is in good state but when i compare the signature of the transistor side with a known good one it gives me different signature...
  13. HellasTechn

    Resistor Value.

    Are you sure it is not a 5,1 Ohm resistor ?
  14. HellasTechn

    How do I figure out what is jamming the RF signal in my garage

    To me it sounds like some parts of your house are shilded. Have you noticed if other rf transmittions go through like cell phone for example or have you tried the remote with new battery or a more powerful one ?
  15. HellasTechn

    Resistor Value.

    I apologize for not writing back all theese days. I am "flooded" with other issues and it may be a while before i can work on that PSU again. I will get back to you in the near future. Just need a little time ! THANK YOU !
  16. HellasTechn

    Resistor Value.

    Where ?
  17. HellasTechn

    Resistor Value.

    Here is the diagram.
  18. HellasTechn

    Resistor Value.

    Yes indeed but im not sure if it was due to output short circuit or power surge. Short circuit most likely. Its a 2sc3679 Im not sure how to do that. could you exlain to me ? The way it is right now it either blows the resistor (the 220Ohm resistor) or overheats and blows output capacitors...
  19. HellasTechn

    Resistor Value.

    the resistor in question is connected as follows. one lead to the optocouplers pin1 (the one with the mark) and the other goes to the outputs positive side and then through an other resistor to the tl431 regulator. picture 1 shows the board. in red is the resistor and the blown cap. in yellow...
  20. HellasTechn

    Resistor Value.

    well... this resistor came out of this power supply. https://www.circuittest.com/s-60-12-ac-dc-power-supply-60w-12vdc-5a.html I can not find a circuit diagram... :( On the circuit it is marked R18 at first i thought it was a 220Ohm resistor and replaced it with a 220Ohm. wen pluged in the...
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