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How to use SCART for our hobby
Atomicburner:
One picture gave me error while posting, lets see if this time the picture keeps posted.
Cheers.
SailorSat:
Hm... Resumé
Sync to 20 only - only black dots -> TV in composite mode
Sync to 16 only - rolling picture -> TV in RGB mode but no sync line connected.
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Try this... Step-by-Step
Step 1 (Black Screen):
VGA 1 to SCART 15 = RED Signal
VGA 6 to SCART 13 = RED Ground
You should see a black screen.
--
Step 2a (Switch to RGB - VGA only):
VGA 9 to Resistor ~68-100 Ohms to SCART 16 = BLANK Signal
VGA 5 to SCART 18 = BLANK Ground
Step 2b (Switch to RGB - PC Molex):
+5V to Resistor ~68-100 Ohms to SCART 16 = BLANK Signal
GND to SCART 18 = BLANK Ground
+12V to SCART 8 = SWITCH Signal
Depending on which way you choose, you manually need to select AV(1).
The screen should turn Red.
--
Step 3 (Add Sync):
VGA 13+14 to SCART 20 = SYNC Signal
VGA 10 to SCART 17 = SYNC Ground
The screen should becomed synched.
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Step 4 (Other colors):
VGA 2 to SCART 11 = GREEN Signal
VGA 7 to SCART 9 = GREEN Ground
VGA 3 to SCART 7 = BLUE Signal
VGA 8 to SCART 5 = BLUE Ground
The screen should be fine now.
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Step 5 (Sound!)
Yes well...
Get a 3,5mm Stereo connector
Inner Pin to SCART 4 = Ground
Middle Pin to SCART 6 = Audio Right
Outer Pin to SCART 2 = Audio Left
Atomicburner:
Hello Sailorsat, thanx, but yet, it was not this time...
(Step 1 (Black Screen): VGA 1 to SCART 15 = RED Signal, VGA 6 to SCART 13 = RED Ground, You should see a black screen.)
Right.
(Step 2a or step2b : , Depending on which way you choose, you manually need to select AV(1). The screen should turn Red.)
Wrong, the screen stays black.
(Step 3 (Add Sync): VGA 13+14 to SCART 20 = SYNC Signal, VGA 10 to SCART 17 = SYNC Ground, The screen should becomed synched.)
Wrong, it appear a black screen with white dots, and its desynchronized.
:banghead: :banghead:
Thanx for the info.
cheers
Zebidee:
Seems that your Sony is in composite mode.
Something tells me that your RGB switching signal is borked. Can you try using the 5v + 100ohm resistor -> SCART 16 again? Leave the casing off your SCART header and use your multimeter to double-check the voltage while in-circuit (ie plugged in) & everything turned on. The voltage should be close to 2v.
If it is ~2v, then try connecting the 5v *without* the resistor - maybe the higher voltage will trigger RGB mode. I suggest this because you seem to get a rolling RGB picture when you connect the sync to SCART 16. Your sync from an ArcadeVGA card is likely at around 4.5-5v.
if NOT (e.g. if it is still 5v), and you are sure there is no other problem, then it suggests that your Sony is not 75ohm terminated like it should be. Try this:
Add another resistor (75 ohm is probably perfect, but one of your 100ohm resistors should do) to the SCART 16 pin or wire, and connect the other end of the resistor to any ground pin (SCART 18 will do, but any is OK - it shouldn't matter much). This will then create a simple VOLTAGE DIVIDER, which would reduce the voltage input to approximately half of what it was before (~2.5v).
Here is the formula at play here, using 100ohm to ground:
Voutput = Vinput * (Rground / (Rinput + Rground))
Voutput = 5v * (100 / (100+100)) = 5v * 1/2
Vouput = 2.5v
To reduce the voltage further you could either add more resistance (ie more or 'larger' resistors) to the input, or use a lower-rated resistor (e.g. 75ohm) to the grounded resistor.
This latter case (using 75 ohm to ground) would then give you:
Voutput = 5v * (75 / (100 + 75))
Voutput = 2.14v
Atomicburner:
Hello Zebedee
I´ve got one problem here, the resistors that i have, are damaged, because i the voltage after the resistor is 5.06, always.
So, i always tested this with 5v direct to Scart 16, hope not to damaged the TV, im going to connect a DVD to see.
Only on monday i can buy some resistors, on monday i will give you news.. thanx for the help..