My Seiki 39in Ultra HD TV is Stuffed because of a Cheap HDMI SWITCH!

[toxsick]

hi there,

I am hopping you can help,

i just received my cheapo nasty hdmi switch box,
plugged it to my seiki 4k, SE39UY04 SEIKI 4K UHD TV
and all &^*# broke loose!

the first thing I remember just after I plugged in the HDMI BOX was seeing was my all blue no signal screen slowly fade to black. and it looked psychedelic. Like a kaleidoscope

ever since then black screen every time I turn the set on.
Only once (1time in 50 trys)I got it to run normally for about 5 minutes then fades to black again
and now never shows an image.

before the hdmi switch the tv was fine!

heres an interesting thinggy!
I can still blindly (remember what to press on the remote control) run a firmware upgrade, to return it to stock firmware thinking maybe that would help..
I remember that the front LED flashes red/blue while perform a firmware update, so that works.

I also was able to change power mode to auto on when ac is connected (I remember an option in service menu to allow me to enable a option that turns the panel ON after electricity is connected.
so it seems the mainboard and firmware are somewhat ok.

so electronically thinking, mainboard is ok? because can still flash firmware and set that auto on thinggy..

unless the main board also handles images, The main board might have like a HALF DEAD thing going on!

the tcon might be the only thing wrong!
I have diagnosed the following

***Tcon fuse is intact
***The TV does have Backlight running, just a blank screen
***I was told to test the on screen display and a torch, cannot see anything
***The Power Unit has a 3v/5v/12v/24v Rails and they are ok.
***The TV has sound via HDMI still!


Thankyou

 

[tunedwolf]

Sounds to me like you may have fried the HDMI inputs on the main board, possibly taking out or locking up video source selection. If all your supplies are up on every board, and the inverters and back lights are lit, your problem lies in the video path somewhere. There is not really any easy way to test the T-Con board besides a voltage and waveform check, but just about any problem in the video path will skew your results and render them inconclusive. The best way would be to drive the T-Con from another source. Either way, it's unlikely to be a cheap fix. Try identifying where video selection is made on the main board and disconnect it from the signal path, then inject your own video source and observe the results directly on screen. If you see a good display, then replace the main board