What are your first thoughts when you see a - Page 1
Forum section: electronics / beginners

author: DreamWalking
author_rank: Newbie
timestamp: April 14, 2020, 10:01:06 am
content: Hello to all, my first time in this forum, I am totally a beginner with electronics and interested in tinkering my way into a better understanding of what makes things work and what goes wrong to make them stop. ... This has lead me to my first question to which I have not been able to find a general rule of thumb answer ... Having been given a non working LG LCD/LED TV, ( 55LW9500 ) that has no visual or audio output, .. I opened it without any workshop manual, my eyes were drawn to the 2 LED driver boards, each had a red flashing LED on it.... Now forget about my LG and simply tell me what are your first thoughts when you see on a circuit board a flashing red LED ... by your experiences, have you found that a flashing LED indicate a fault situation or a correctly working circuit ?

author: NivagSwerdna
author_rank: Super Contributor
timestamp: April 14, 2020, 10:45:37 am
content: I considered repairing my LG TV once (but luckily established that my extended warranty had one month left so could get it repaired professionally) and my experience was that technical information was non-existent and parts unobtainium. I think LG repair is done by a secret society of some kind. As to your question... no idea... if it is a 1Hz flash then possibly it's a little lighthouse to guide the little people living inside the TV... if it is a specific number of flashes... pause... repeat... then maybe an error code.

author: Sam Spastic
author_rank: Regular Contributor
timestamp: April 14, 2020, 10:47:23 am
content: Having seen many flashing LEDs and many LEDs that are just on. In 40 years of industrial electronics troubleshooting I have learned that these LEDs are all telling me that there is some sort of POWER to the circuit.If you have the correct service manual then you can tell if these also mean other things like...1: OK2: Oh Shit3: OH!4: OH?

author: Sam Spastic
author_rank: Regular Contributor
timestamp: April 14, 2020, 11:00:31 am
content: Tryhttps://elektrotanya.com/Sign up , go to the SM SEARCH page, enter model number, voilà.

author: DreamWalking
author_rank: Newbie
timestamp: April 14, 2020, 11:22:28 am
content: Sam ... Thank you for the link, I have visited the suggested site, and free of having to sign up I was allowed to download the Service Manual which most certainly will be of great use, as was your 40 years of experiencing flashing LEDs, now that I am in retirement and slowing down I want to pursue my interest in electronics and ask .."Why is it so?" as did a famous man in my younger day, Dr Julius Sumner Miller. I just hope that my eyes will support my interests.NivagSwerdna .. Thank you also for your reply all information is of value when you place it into a collective to discover the right direction to go.

author: DreamWalking
author_rank: Newbie
timestamp: April 16, 2020, 10:41:58 pm
content: Sam .. Due to your pointing out where I could find the service manual for my repair project, I now have a spare fully functioning LG 55" TV ... sitting in my lounge room. ((now I can watch stereo TV)) .. if my skills develop I might build a Quadraphonic TV system ... LOLNow the service manual never gave me any hint on what the 2 flashing red LEDs were .. and silly me over looked taking note after the fix whether they were on, off or flashing...LOL .. next time I remove a bucket full of screws, I'll have a look.The value of the service manual for me was the flow chart, by following its logic and pathways it pointed to the motherboard as being the fault, ... classically the main processor chip had developed faulty solder joint(s).Thank you .. Peter.