F42k20e

[Coinhunter]

A friend just gave me this TV and of course I need some assistance with it. All 7 threads about this unit are different from mine as they must have made 15 million different versions with the same model number just different parts. I am fairly certain I have it narrowed down to the audio/video main board as the problem but I am not a guru like you guys and I really appreciate it when you take time to help an old fart. Anyway when turned on it powers up, blue screen comes on looking for source then is go bat crazy. It starts poping and cracking, the screen stays blue but there are lines all over it, then it will clear for a second then back to the crazy stuff over and over. The poping and cracking noise coming through the speakers is really bad and it will not let me turn the volume down. If you folks can help me fix this I plan on giving it to a couple whose old set is on it's last legs. Thanks in advance.

[maxvalutech]

Re: F42k20e

You really need to supply the various voltages you read firstly from PSU to ensure its operating OK then the main board check of voltage regulators etc. Is the set tuned in, is the antenna connected ?

[dick_barton]

Re: F42k20e

The voltages are given in the red box and should match what you read on the pins of XP901

[Coinhunter]

Re: F42k20e

I just measured the voltages Dick and noticed I had posted an incorrect picture. Here is the correct board with the vo;tages and connector marked in red like yours. Thanks Ralph

[budm]

Re: F42k20e

https://www.badcaps.net/forum/attach...5&d=1515606978
I do not see the Voltage readings for the STB (PS-ON), SW (BL-ON), and BRI (Dimming).

[Coinhunter]

Re: F42k20e

Okay 3rd. try my bad, just don't believe I think it through completely that is why I asked for help. Thanks for being patient with me. Seriously now I believe I have everything in the picture measured and I remembered to plug it in connect the power and main boards and turn it on LOL Major voltage changes on a couple in my thinking (maybe not to you guys). From looking at other boards the voltages for stb, sw, and brt/dim seem to be relatively correct. I updated the photo to show changes. Thanks

[dick_barton]

Re: F42k20e

There are at least two voltage regulators on the mainboard. What are the voltages on the 3 pins of each.

[Coinhunter]

Re: F42k20e

Measurements for the 2 voltage regulators showing all 4 legs relative to position on board with chip id

[Coinhunter]

Re: F42k20e

Totally repaired guys, thanks for the help.