tv cyberlux model tv 20 cx, chassis 34BI tuning fault
Check this diagram if it's your tv https://elektrotanya.com/cce_hps-1471_hps-2071_chassis_34bi.pdf/download.html
If it is your TV please go to page 58 is the tuner you will see that a transistor q101 appears as the voltage regulator, change it together with the zener dz 102 zener 5 volt and the diode d101 q is a diode 1n4148 and change the c107 filter of 470uf x 25 volts these carry the 5 volts and by your comment I assume that when heating the transistor enters cut-off by blocking the 5 volts if doing so persists then we go to the flayback which is the one who gives the 12 volts for beef lowered to 5 by the transistor q101, you would exchange c426 of 470 uf x25 volts change the fr402 from 1 ohm to 1 / 2watt and the diode
And the diode d402 code skf4f1 of not ayar this diode can put any high-speed diode of 1 amp or failing 1n4007 and the capacitor c420
these voltages usually come from the power source or the flaybak follow the track review the weld by the selector area
thanks for the leasmacruz contribution, if it's the tv, I'll make the changes and then comment the results.
Greetings colleagues followed the advice of the colleague leasmacruz and replaced the transistor q101 and the 470 microfarad capacitor with 25 volts and the 5 volts were restored in the selector and tuned the channels perfectly, please friend leasmacruz place the proposed solution to close the post, in the same way thanks to all the colleagues who left their contribution to help me with this fault ...
