New TV woes with PROP 1

AGCB

I upgraded to a larger flat screen TV to use with my Quickstart board but get only garbage. Can faintly see what is supposed to be there but lots of diagonal static. I have it hooked to a RCA video jack and correct input selected on TV. Tried switching back to old TV and works fine. I've looked at all the menu options on the TV but still pulling hair! What might I look for"
Thanks
Aaron

Phil Pilgrim (PhiPi)

Are you providing an NTSC signal from the Prop? What resistors are you using in your output circuit? What make and model is your TV?

-Phil

Rayman

Maybe it's actually the component input instead of AV? Maybe set to PAL instead of NTSC?

AGCB

The TV is a Bravia KDL-40V2500. The resisters are 1.2k, 560 and 270. Using TV_TEXT object. Tried all video input jacks on TV (3). It works on another flat screen that I have.

Rayman

If those 3 video jacks are colored green, red, blue then it's component input, not NTSC...
NTSC jacks are usually yellow...

Phil Pilgrim (PhiPi)

This is a better resistor network, since it provides video output at the correct voltage and impedance:



But maybe the TV's video input is not terminated. If that's the case, try adding a 75-ohm resistor from the resistor network's common node to ground.

-Phil

rbehm

Ground issues between the prop and the TV?
Try to measure the (AC-) voltage between prop GND and TV without the video cable plugged in.

AGCB

Phil
I'm assuming that in your schematic the base pin is on bottom (866).That's how I did it on a breadboard for temporary. But! those are not standard resistors so I made some series/parallels. It works perfect now, very stable display!
Thanks to all who replied
Aaron

Phil Pilgrim (PhiPi)

You're right: those resistor values are not standard for 5% resistors, but for 1% resistors. 'Glad you got it working!

-Phil

Mark_T

Surface mount resistors are mainly 1% or better these days, so yes its standard values!