View Full Version : Sony KV-2643R composite injection


freakaftr8
10-18-2020, 02:16 AM
Hey all so I have this Trinitron KV-2643R that I just brought back from the bowels of the deep and installed a A67JHG01X from a roach infested tabletop. Dialed in and looks good but I'm interested in injecting composite or even better svideo into the chroma/luma pins at the jungle. It's a Sony CX-556 IC. Have no specs on it. Or a sams on the set. I've done many RGB mods on trinnys and others of the such, but usually have a schematic to help me out. Any ideas?

Thanks!

damen
10-18-2020, 08:47 PM
Looking at Sams set 1932, folder 2, chroma goes in on pin 13, and video on pins 5 and 6.

freakaftr8
10-18-2020, 09:31 PM
Your awesome thanx! Gotta run to Seattle for a job so its going to be a few weeks on the backburner but I'll let you know know it goes.

freakaftr8
10-19-2020, 10:59 AM
Looking at that schematic I could inject my video at the base of the video amp and remove the incoming out of circuit, to eliminate interference from the tuner, I could inject the Chroma at pin 13, but may need a .01 cap to drive down the signal as it will probably be to amplified, and maybe 75 ohm to ground, not sure yet, but based on this, I dont want video to go direct to pins 5 and 6, since I will be bypassing sharpness and sync, that's still needed in the circuit, but I may have to come up with a voltage circuit to amplify the composite to the jungle or there will be nothing there to boost the composite signal and it will be dull since i will essentially be cutting out the tuner on board . Does that sound about right?

On the other hand, simple composite input would be easy, I would just dump the composite at the detector off video amp but may still need to amplify voltage there with something like a 2N2222

freakaftr8
10-22-2020, 10:48 PM
Looking at Sams set 1932, folder 2, chroma goes in on pin 13, and video on pins 5 and 6.

Hey looking at that schematic it's kinda blury showing the video amp circuit. Does that say IC202 or IC302? I see a TP22 that i believe i can tap into and ground at the IC. Thanks again!

damen
10-23-2020, 08:52 PM
I'm confused. There is no IC302 in this set, and IC202 is in the audio circuit. Also, I can't find test point 22. Tell me what part of the diagram you need a better picture of and I'll try to do my best.

freakaftr8
10-23-2020, 09:23 PM
Ahh sorry, i meant q202 or q302. Tp22 is at the base of the video amp transistor.

freakaftr8
10-23-2020, 09:24 PM
I'm confused. There is no IC302 in this set, and IC202 is in the audio circuit. Also, I can't find test point 22. Tell me what part of the diagram you need a better picture of and I'll try to do my best.



Yep thats it! Thanks again ill inject composite at TP12 and ground at the IC302 ground. This will give me composite.