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Anthony_Infotech
Anthony_Infotech, Technician
Category: TV
Satisfied Customers: 13713
Experience:  20+ years experience TV expert (field and bench) 9 approved qualifications in TV-ELECTRONICS
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I have a toshiba 55ht1u led tv no sound no pic or backlight

Customer Question

I have a toshiba 55ht1u led tv no sound no pic or backlight only the green light comes on. I have replaces the burnt master backup boards 1&2 but not the slave boards i have also replaced the power and main boards all to no effect whats next
Submitted: 9 months ago.
Category: TV
Expert:  Anthony_Infotech replied 9 months ago.

Hello

Welcome

Was this the original issue with the set?

If you connect up a DVD player and slowly cycle the INPUT button does the sound come through?

Anthony

Anthony

Customer: replied 9 months ago.
I put a movie on my computer and plugged in the hdmi hitting the input button twice every 30 sec or so
Expert:  Anthony_Infotech replied 9 months ago.

And this was the original issue with the set

Customer: replied 9 months ago.
it lost everything but the green light
Expert:  Anthony_Infotech replied 9 months ago.

Set is running there may be a voltage rail down if you have no sound but you replaced power and main same symptoms, are you sure there is no backlight?no visible signs of light even in a dark room because from what you are saying and if this has stayed the same symptom throughout it does not make sense

Customer: replied 9 months ago.
No backlight maybe i should try hooking up something other than my comp
Expert:  Anthony_Infotech replied 9 months ago.

Yes you can do that but you see you have replaced the power-board which eliminates any missing voltages for the no sound and no backlight condition and in addition the mainboard too so there is something odd if you have done that, I am not sure if this set uses a backlight inverter or 2 (cant find the data on it in my database yet) or if its an LED backlight?if its LED this is usually a lead from the powerboard that disappears into the panel

Customer: replied 9 months ago.
It has 4 backlight inverter boards two master and two slave the masters were burnt through i have not replaced the slave boards yet trying to get sound first
Expert:  Anthony_Infotech replied 9 months ago.

Processing for the sound will be on the main-board I suggest you try another input like a DVD player as there may be a comms problem with the computer, let meknow

Expert:  Anthony_Infotech replied 9 months ago.

Yes there should be sound here regardless if the master/slaves are working or not

Customer: replied 9 months ago.
I just hooked up a vhs need to cycle through inputs
Expert:  Anthony_Infotech replied 9 months ago.

Then you would be looking to replace the slaves if the sound returns

Expert:  Anthony_Infotech replied 9 months ago.

And you also have to hope that the backlights themselves have not been damaged

Anthony

Customer: replied 9 months ago.
Cant seem to find any sound maybe i got a bad power board from ebay
Expert:  Anthony_Infotech replied 9 months ago.

Use a meter to check the voltages they should be stamped on the board

Expert:  Anthony_Infotech replied 9 months ago.

Its possible but to show the same issue seems improbable

Expert:  Anthony_Infotech replied 9 months ago.

Same thing could be said about the main-board but is improbable.......this is odd

Expert:  Anthony_Infotech replied 9 months ago.

I do hope you know the history of the set?the set has not been subject to storm damage?

Customer: replied 9 months ago.
I bought it new its 6 yrs old
Expert:  Anthony_Infotech replied 9 months ago.

OK I would suggest you send back both main and power and perform the test again when boards arrive, i do not use ebay only as a last resort best using suppliers like www.shopjimmy.com

Expert:  Anthony_Infotech replied 9 months ago.

Please make sure you have provided the correct model number for the set re-check thanks

Customer: replied 9 months ago.
Shop jimmy didnt have power board unfortunately i got the main board from them yesterday
Customer: replied 9 months ago.
there are no other boards i need for sound but main and power?
Expert:  Anthony_Infotech replied 9 months ago.

Is the model definitely what you said?you have checked

Customer: replied 9 months ago.
Expert:  Anthony_Infotech replied 9 months ago.

I am 90% sure will check now, there is no terminal board for the INPUT connections?

Customer: replied 9 months ago.
They are on main board
Expert:  Anthony_Infotech replied 9 months ago.

Yes its just if there was a separate board but all processing for the signal for the sound comes from main, power to main and maybe sound output from power-board, it really just leaves the speakers have you checked those?

Customer: replied 9 months ago.
No ill have to get a differant tester and go over the power i know im getting 5v to the inverter standby and 117 coming in thats all ive been able to check
Expert:  Anthony_Infotech replied 9 months ago.

Just check the speakers on ohms they should read about 8 ohms if not they are open circuit, read across terminals

Customer: replied 9 months ago.
Ok
Expert:  Anthony_Infotech replied 9 months ago.

Its the only thing left to check for the no sound issue

Customer: replied 9 months ago.
Damn i got 0
Expert:  Anthony_Infotech replied 9 months ago.

If the meter is swinging to near 0 ohms then although that is not correct its safe to say the speakers are working, its only if there is nothing happening with the meter and it reads OL

Customer: replied 9 months ago.
Rechecked with big tester they're good
Expert:  Anthony_Infotech replied 9 months ago.

Back to plan A with replacing main and power, you do see the speaker leads going into the mainboard?if so then its still plan A

Customer: replied 9 months ago.
i got the main from jimmy do they sell refurbished or new
Expert:  Anthony_Infotech replied 9 months ago.

No you will find all boards from any supplier will be pulled from scrap sets

Expert:  Anthony_Infotech replied 9 months ago.

Boards new if available would be too costly

Customer: replied 9 months ago.
Ok ill give them a call, thanks for your help
Expert:  Anthony_Infotech replied 9 months ago.

Ok let me know how it works out this has to be either that main or powerboard you got

Expert:  Anthony_Infotech replied 9 months ago.

Please consider rating the answer positively there will be a rating bar of stars usually at the top of the page with this post thank you, ***** ***** positively enables me to receive credit from the site thanks again, the session will remain open and stay open as long as you need it, if you have any concerns please just let me know and I will answer any queries you have

Many Thanks

Anthony

Expert:  Anthony_Infotech replied 9 months ago.

Do you still need help with this please

Anthony

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