What year is your car? You may have the A4LD of which there was an early version and an updated version. Im not all that familiar with the TV cable mentioned as I do not have one. I have just a simple kick down cable that doesn't even need to be connected if it failed. I have the early version A4LD on my 87 which has a single solenoid for a "fake" 4th gear that really just locks the torque converter while in 3rd gear. 1-3 gears are mechanical valves. On the later version, there were two solenoids. One to lock the TQ for the fake 4th gear, the other replaced the valve for the 2-3 shift. One way to check is to unplug the electrical connector on the drivers side just in front of the gear shift lever. The early version has two pins. The later version has 3 pins. The easiest first thing to check is the vacuum modulator. If you aren't familiar with this, it's on the passenger side of the tranny. very visible from under the car. Youtube it. It has a vaccuum hose connected to it. Pull the hose off and if there is tranny fluid in the hose, that modulator diaphragm has failed. You might also have white smoke on start up because that fluid does get sucked up into the intake. It's a cheap fix and just one small bolt holding it in. A little tricky to put back on. If you do remove it, be sure not to lose the pin that will fall out. It's about an inch long. It has to go back in.
If this isn't the problem that fixes your issue, the next thing would be to drop the pan and replace the 2-3 shift solenoid. Hope some of this helps