Have had this TV since June 2019, worked fine till today. Daughter was watching it and made a noise and went dark. I unplugged, left off then powered back on, no change. You can see the image with flashlight test, but has high pitched noise/whine and no backlight whatsoever......I also tried a factory reset with the reset button on the back. Any ideas where I should start troubleshooting? Im pretty good with soldering iron and multimeter, but I dont have any documentation on this TV so I dont know where to start.
TCL 75R615 has sound, no backlight
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Re: TCL 75R615 has sound, no backlight
So, I got some help yesterday to take the TV off the wall and got the back off to check out the boards....I did find a capacitor that was blown out,looks to be C312 a ceramic disc capacitor, very small and challenging to read, but was able to with a magnifying glass.....it seems to be a 220pf 1kv, I ordered some new ones from digi-key. A couple of questions, I dont notice with this type of capacitor that there is any polarity that needs to be observed? I have replaced numerous electrolytic caps and they have obvious polarity markings on the circuit board as well as the cap itself. Please see the attached pictures of the part number of the panel as well as some pictures of the internal boards, please offer up any help if you can....Thanks.Comment
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Re: TCL 75R615 has sound, no backlight
I just checked the component via continuity test and it is shorted.Comment
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Re: TCL 75R615 has sound, no backlight
I think I'll wait till I receive the new component, before I power it back up....Comment
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Re: TCL 75R615 has sound, no backlight
When you say take the disc cap out of circuit, I'm assuming you mean the one that blew up and not another one near it or a different one? I did desolder it took it out of circuit and it tested shorted out ....I'll also check the two MOSFETs like you suggested......crap, I already bought the 1kv version instead of the 2kv like you said.....Comment
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Re: TCL 75R615 has sound, no backlight
QW301 & QW302, as far as testing them....can they be tested in circuit, or do they need to be removed to be tested, I just want to make sure I do it the correct way.....im sure I can google a testing procedure, but I want to do it the quickest, most correct way....
Please let me know and thanks again for everyones help with this, it is much appreciated.....Comment
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Re: TCL 75R615 has sound, no backlight
Ok, I'll test them later on this afternoon and post results on the mosfets....Comment
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Re: TCL 75R615 has sound, no backlight
I tested both QW301 & QW302 in circuit and they are testing open across all legs.....I'm assuming per previous post that this means they are most likely good....Comment
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Re: TCL 75R615 has sound, no backlight
Ok, does anyone have a good source for how I should be testing these particular mosfets? Ive viewed a few videos on youtube, but just looking for suggestions.....
Thanks!Comment
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