[STILL AT IT] Think I fried it. Heard a sizzle.

NewHome Forums OSSC, OSSC Pro and DExx-vd isl OSSC – DIY Support [STILL AT IT] Think I fried it. Heard a sizzle.

Viewing 8 posts - 31 through 38 (of 38 total)
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  • #24368
    mikklejickles
    Participant

    Update : I bought a HDMI to VGA converter to see if I could see anything – as my HDMI tester says everything about the signal is good connectivity wise and voltages on all pins for HDMI are about 2.7v.

    Again no signal on PC input.

    At this point I wonder if I could jump the VSYNC, HSYNC signals directly to a VGA cable and see if I can get anything.

    #24369
    Morpheus_79
    Participant

    Maybe your TVP7002 is broken and your OSSC just outputs a blank video signal!? Did you solder the middle grounding plates of the TVP7002 and the FPGA to the pcb (in fact: i did remember reading about some problems from people who left them unsoldered)?

    Still a strange issue, since your OSSC seems to work exactly as it should (it recognizes a signal and seems to output… something).

    #24375
    mikklejickles
    Participant

    All ground plates are soldered for sure.

    Does the test pattern rely on the TVP (where is that actually generated – i think it might be the ITE chip but I’m not sure!)?

    My guess is that the TVP needs to work in order to get the Red ‘Sync’ led to go out (as it is then sync’d and locked to 59.59Hz on some input).

    Because both the test pattern AND the sync’d input from scart are not outputting anything, I’m guessing it’s something downstream of the inputs.

    #24388
    marqs
    Participant

    The traces in previous page look correct except that HSYNC and VSYNC are not aligned but that’s probably due to scope settings. You should also check PCLK signal between FPGA and IT6613 and DDC5V fuse (before HDMI pin 18). TVP7002 should be ignored until you get the basic test pattern displayed.

    #24397
    mikklejickles
    Participant

    I will check pclk signal today. Thanks for input marqs!

    #24417
    mikklejickles
    Participant

    Checked PCLK and looks like I have very low voltage signal maybe .02v and there is a pattern on the scope. I measured voltages on every other FPGA pin and they look ok no bridges.

    If PCLK at low voltage is wrong that may be my problem.

    #24435
    mikklejickles
    Participant

    Hi folks,

    Here are the pinout voltages of my FPGA for reference when it is switched on (Red LED off, Green On).

    If anything looks blatantly off here let me know (for those that are that deep in this that they know these values!)

    RED – 3.3v
    YELLOW – 1.2v
    LIGHT BLUE – 0.6v
    BLUE – 0.1v to 0.4v
    GREY – GND or 0v
    RED BOX – Other voltages 1.5 to 3.27v
    BLUE BOX – Very low voltage (< 0.1v)

    OSSC FPGA Pinout Voltages

    #24474
    mikklejickles
    Participant

    Same for TVP Chip

    RED – 3.3v
    YELLOW – 1.9v
    LIGHT BLUE – 0.6v
    BLUE – 0.1v to 0.49v
    GREY – GND or 0v
    RED BOX – Other voltages 1.6 to 3.24v
    BLUE BOX – Very low voltage (< 0.1v)

    OSSC TVP Chip Pinout Voltages

Viewing 8 posts - 31 through 38 (of 38 total)
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