I recently picked up an Akai CFT2490 after seeing some discussion about that model
here in this thread. I was able to find a service manual for the TV, and learned that it's actually a rebadged Samsung (specifically a
CFT24907X/SMS). As discussed earlier in this thread, the A/V connectors on this TV are actually a SCART connector on the mainboard, and it was super simple to get the RCA jacks removed and a SCART socket installed in their place.
The service manual indicates that the resistor on SCART pin 8 (R717, physically missing from the board) should be a 39K resistor, which is also one of the values that MarkOzLad worked out assuming that R715 is part of a voltage divider for that line (
again, earlier in this thread).
I soldered one on and tested out some games, and the results were pretty good!
However, the TV did not switch to the SCART input when powering on a console. I know that the consoles I was using output 5V on pin 8 instead of the 12V that the TV is presumably expecting, so I tried swapping out the 39K resistor for a 10K resistor. (I'm no electrical engineer, but a voltage divider calculator indicates that I would get the same resulting voltage that way.) This also doesn't seem to have done anything to get the TV to automatically switch inputs. If I had to guess, I'd say that since this model was sold in the US, its firmware probably just doesn't do anything with the input from SCART pin 8. Pin 16 connects directly to the RGB Enable pin of the jungle chip, so as long as the TV is set to the right input, I'd be willing to bet that it would work just fine even without any connection on pin 8 at all.
The TV itself has some geometry issues that the service menu doesn't seem able to fix, specifically with some uneven line lengths down the height of the screen, as well as stretching toward the left and right edges of the screen (which I understand is partially, if not fully, due to the fact that it's a flat-screen CRT.) I'm considering recapping the whole mainboard, since I've read that it can help with geometry issues like that, but it's definitely uncharted territory for me, so I'm keeping my expectations pretty low.
That aside, though, I'm still real happy with it! It's satisfying to be able to do such a simple mod to get a great picture out of a TV I paid $5 for.