Sony Bravia KDL-40RD455 repair - Page 1
Forum section: electronics / repair

author: kjr18
author_rank: Regular Contributor
timestamp: September 19, 2018, 07:33:23 pm
content: Hi, I have a problem with this tv. It works for some time, then display dies. Backlight is still on but no picture. As this tv is fairy new, all that I found is about someother model that has probably the same logic board. From what I read there it looks like lvds chip might not work properly. IC6016 next to it is probably a ldo, it supposed to be a 3.3V to 1.1V (or maybe1.2V) regulator, but on it's output there is only about 0.9V when you can see picture on display, and when picture disappear output drops to around 0.4V. Is that vreg faulty? If is, what can I use to replace it? I tried looking for some data on it, but I didn't found anything. It's a so-23-5 package with marking 9116J, other markings mentioned in mentioned forum thread are 91162 and 9116N.

author: Mario87
author_rank: Frequent Contributor
timestamp: September 20, 2018, 10:48:11 am
content: What is the input to the regulator when the TV is working and when it's not? If the input is dropping too low then the output will always be low, so it could be something before this IC in the circuit causing the issue.If the input voltage remains stable, but the output drops too low, then quite possibly the IC is faulty.

author: wraper
author_rank: Unknown
timestamp: September 20, 2018, 11:03:54 am
content: You can replace it with other MLCC tolerant LDO in SOT-23 package, say TLV70311DBVR or TLV74311PDBVR

author: wraper
author_rank: Unknown
timestamp: September 20, 2018, 11:10:32 am
content: http://www.lcd-television-repair.com/newsletter/24-9-2017/Sony-Smart-LED.pdfit certainly should be 1.1V after IC6016 (Page 59 and troubleshooting guide)

author: kjr18
author_rank: Regular Contributor
timestamp: September 20, 2018, 12:03:38 pm
content: Both input and enable voltage are 3.3V at all times. Whats the best about this tv, that's it's warranty ended about week agoQuote from: wraper on September 20, 2018, 11:10:32 amNice pdf you got there. For sure it will help with this repair.

author: Mario87
author_rank: Frequent Contributor
timestamp: September 20, 2018, 12:08:26 pm
content: Quote from: kjr18 on September 20, 2018, 12:03:38 pmTypical! Almost built to fail just out of warranty! If the input is a stable 3.3v and the output is struggling to go above 0.9v when it should be 1.1v I would certainly look at replacing it with another suitable IC.

author: kjr18
author_rank: Regular Contributor
timestamp: September 20, 2018, 05:49:12 pm
content: How about TLV73311PDBVT? Would it work alright? I ask this because this one is more accessible for me than those other two.

author: wraper
author_rank: Unknown
timestamp: September 20, 2018, 06:25:27 pm
content: Quote from: kjr18 on September 20, 2018, 05:49:12 pmShould be fine.

author: kjr18
author_rank: Regular Contributor
timestamp: September 27, 2018, 08:09:49 pm
content: I replaced this ldo and tv works like w charm! Thanks to everyone who decided to help. I wonder how many tv's are thrown out just because something small as this fails.

author: Fabian
author_rank: Contributor
timestamp: February 13, 2021, 11:56:32 am
content: Hi everyone,just wanted to let everyone know that I fixed a Sony Bravia KDL-49WD755 with the same issue. The symptoms were a bit different: There was an image but it wsa flickering heavily and it was not possible to use the TV.The output voltage of the LDO was, as described, below 1.1V (like 0.7-0.9V). After replacing the LDO with the part listed above it works perfectly fine nowThanks a lot!