https://elektrotanya.com/rca_chassis...wnload.html#dl hey i found the service info. with thosehttps://elektrotanya.com/rca_chassis_ctc203_training_manual.pdf/download.html#dl sets the tuner ground did not have goo solder from the factory. that cause the e prom go bad, but first check the voltage on the vert side only see if what the reading is. plus do a ohms check on that side. i leaning towards bad vert chip. the e prom was just for a few chassis. the bread butter of shop. give that a try.