You the man
... I jtaged than tested lnbp8 IC as per your instructions and found pin 1 to be my problem. I replaced R184 with a 15 OHM resister and all is good. Thank you for your time and patience...
Thank you
Maybe a MOD can change the title of the thread to " No Vertical or Horizontal Signal "...
p
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Originally Posted by fugley
If you would like to test the lnbp8 IC for sure you can check these pins in this order
pin 2 should be ~22 vdc if not you have a power supply prob
Pin 1 should be ~20 vdc if it is more then 2 volts lower then 20 and pin 2 is ok then R184 the large 2 1/2 watt resistor is open or loaded by a defective lnbp8 a 12 to 15 ohm should be a good replacement see ST data sheet page 5 note (1) if both of those check ok then pin 4 should be zero = gnd. pin 5 should switch from ~3 vdc = H to ~0 vdc = V as you change channels. if not then you have a problem coming from pin193 of the main sti 5518 processor and would by the symptoms that you describe most likely be a corrupted base (full) "flash" and could require an actual jtag to properly recover it (think of it as bios flash on your desktop) where a serial flash is like loading the operating system (windows??lol) if your bios is screwed then your windows will not work right, if you get the drift?. Now if this is switching ok then check that pin 6 is at ~3 vdc always(chip enable) pin 7 should be always at ~ 0 vdc now the defining test if all of those were good you can check pin 3 for ~17.3 vdc = H & ~12.5 vdc = V as you change channels, if not then yes very likely the lnbp8 is defective. I hope this helps. Sorry about the crappy pic but best I could do in a hurry. good luck. oh as for that wire don't even think about it that was someone elses project and better not discussed here and no it didn't go to a switch
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