JVC CX 710 VHF/UHF tuner repair.

[ELzekio]

For the tests I’ve been doing so far while this thread has been posted, I have been useing a vcr connected to the CX 710s coax 75 ohm input and NOT my blonder tongue.

*when ever I did though try broadcasting over the air with my blonder tongue I would still get the same results I get when having a vcr directly connected to the unit.*

While having the vcr connected again and having the vhf tuner tuned to where it should have the strongest signal, I felt around but i did NOT notice the IC 101 chip getting hot.

I really don’t think anything is wrong with the IC itself. The voltages as posted above are fine, except for the fact that pins 4 and 14 are still showing the N.S voltage for No/Low signal even though I had the vcr signal connected to the unit and tuned to where the signal is supposed to be strong.

I then tried adjusting the noice control according to the service manual, but it did not make a any meaningful difference in the picture at all.

As i mentioned before I am confident the signal is getting to the TU-01 tuner, because I tried injecting it directly into it and got the same results as always. If IC 101 is good, then it is possible that the TU-01 tuner has a problem?

Is it common for those tuner boxes to go bad?