OSSC 1.6 – Plugged in wrong PSU

NewHome Forums OSSC & OSSC Pro OSSC – DIY Support OSSC 1.6 – Plugged in wrong PSU

Viewing 8 posts - 1 through 8 (of 8 total)
  • Author
    Posts
  • #49647
    oddz
    Participant

    Hello,

    I accidently plugged in the wrong PSU adapter in my OSSC (i was drunk), it didn’t turn on anymore. I checked my fuses and realized the F1 burnt. I had no replacement component so I bridged it. F2 and D5 show continuity though. Now my OSSC does turn on but I have no sync, no image shows up. I remember there used to be a black and white screen with squares when I turned the thing on, I don’t have that anymore. Any idea which components to check/replace ?

    • This topic was modified 8 months, 2 weeks ago by oddz.
    • This topic was modified 8 months, 2 weeks ago by oddz.
    • This topic was modified 8 months, 2 weeks ago by oddz.
    • This topic was modified 1 month, 1 week ago by BuckoA51.
    #49669
    Morpheus_79
    Participant

    Had the wrong PSU reversed polarity or a higher voltage? Did you check all the voltage regulators for shorts? Does the LCD of your OSSC works fine and shows no ‘Init Error'(?) – like described here:

    OSSC Init Error -2. Need replacement

    #49671
    oddz
    Participant

    Thanks for you reply,

    I plugged in a 12V PSU. The LCD works just fine and shows no error, it reacts well to the remote controller too, channels, etc…
    Not sure how to check properly if voltage regulators are shorted, they have 5 pins. I place the red of my multimeter on one pin and the black on ground, if I have continuity the component is dead, right ?

    #49673
    Morpheus_79
    Participant

    From here:

    https://github.com/marqs85/ossc_pcb/blob/v1.6/assembly/assembly_tips.txt

    -on bottom side, there are 8 small regulators in SOT-23-5 packages (U6, U7 etc.). Verify with a continuity meter that only the middle pin on the side with 3 legs is connected to ground
    -on top side, there is one larger regulator (U5) behind the display. Verify that only the middle pin (on the side with 3 pins) and the heatsink pin are connected to GND

    #49689
    oddz
    Participant

    Ok, so after tests, U6 and U16 have one pin shorted to ground on the 2 pins side, and U5 has 2 pins shorted to ground on the 3 pins side, the middle one is not shorted to ground which is weird, no ?

    #49703
    marqs
    Participant

    Sounds like there’s something wrong in the measurement or parts are different – is the board DIY, bought from VGP or elsewhere? The symptoms indicate U3 may have been damaged which has been the case with some other people.

    #49718
    oddz
    Participant

    I don’t know about the board, I bought it second hand on Ebay.

    I don’t think my measurements are wrong, I checked again.
    I have ground on the middle pin (on the 3 pins side) on all regulators except on U5. U6 and U16 have one pin shorted to ground on the 2 pins side, and U5 has 2 pins shorted to ground on the 3 pins side. U3 seems ok.

    #49727
    marqs
    Participant

    U6 and U16 are either using a different part (that has additional ground pin on the other side) or their output is shorted to ground. You should measure their output voltages. Since FPGA and character LCD are working, U5 should be fine.

Viewing 8 posts - 1 through 8 (of 8 total)
  • You must be logged in to reply to this topic.