EEVblog #631 - Soniq LCD TV Repair Part 2 - Page 1
Forum section: electronics / general

author: Stonent
author_rank: Super Contributor
timestamp: June 17, 2014, 12:40:11 am
content: I found the datasheet for the suspect part:

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: June 17, 2014, 01:54:44 am
content: the fuse is made by Little Fuse ,LF catalog number 0468 01.5 .Slow blow ! marked TK .http://www.farnell.com/datasheets/94905.pdf

author: nowlan
author_rank: Frequent Contributor
timestamp: June 17, 2014, 03:26:46 am
content: I thought had other issues originally, like no tv signal, only pi on hdmi, and issues turning it off. Wouldnt have thought the flex cable would cause that.

author: pickle9000
author_rank: Super Contributor
timestamp: June 17, 2014, 04:47:34 am
content: I wonder how many people on this forum end up fixing their mom's TV? I do believe it's mandatory.How come everyone thinks anyone involved with electronics in any way shape or form is a TV repairman?Quotes:"You own a soldering iron? Can you fix my TV?""Oh your an Electrical Engineer? Can you fix my TV?"

author: komet
author_rank: Unknown
timestamp: June 17, 2014, 08:54:41 am
content: Quote from: pickle9000 on June 17, 2014, 04:47:34 amIt applies to anyone, even people who can't wire a plug."I brought you into this world and wiped your bottom. Can you fix my TV?"

author: tom66
author_rank: Super Contributor
timestamp: June 17, 2014, 09:01:56 am
content: I "fixed" my Mum's TV because I found it at a dump and replaced the bad capacitors on the PSU, does that count?

author: digital
author_rank: Contributor
timestamp: June 17, 2014, 09:48:12 am
content: Dave as you would know fuses have a mind of their own especially slow blow fuses, that cheap and nasty connector would probably would have resulted in a large repair bill or the set would have been landfill Mum will be happy.

author: nowlan
author_rank: Frequent Contributor
timestamp: June 17, 2014, 09:51:06 am
content: I replaced some caps in psu for a friends lcd monitor. Only to break the flex cable socket on the motherboard. After which it just palette cycled. Called it quits and went to hard rubbish.

author: swabaxter
author_rank: Newbie
timestamp: June 17, 2014, 10:18:36 am
content: This was the first time I had seen inside a modern LCD TV. It's surprising how little electronics there is inside. A great piece of trouble shooting by Dave to find the blown fuse and identify the flat flex as a possible cause.

author: RupertGo
author_rank: Regular Contributor
timestamp: June 17, 2014, 10:27:13 am
content: It's barely worth fixing your mother's TV these days, even if it's just a fried cap or mis-seated cable. As everyone else on the planet has, I fixed one up for my mother when the parental CRT dinosaur finally faded to grey - a pa had a (then very expensive) Samsung 40" LCD which had, in his words, "belched funny smelling smoke from the back and the picture went funny". He gave it to me rather than getting it fixed, and one new cap later it went to the wrinklies.It was fun to fix and the parents were delighted to get a modern telly. But adding up time and transport costs, and the sad fact that few people of my parents generation care much about picture quality (or aspect ratio. Drives me batty when I visit) it would have been simpler and cheaper just to send them a Chinese cheapy via Amazon.But it's good to keep one's hand in - another reason I like EEVBlog so much; Dave spends his time profitably doing the stuff I'd like to do if I could afford to, because that's the way I'm wired. Beats the footie by a very, very long chalk.

author: station240
author_rank: Unknown
timestamp: June 17, 2014, 05:39:21 pm
content: My assumption is the socket o the LVDS board is really critical as to the entry angle of the matching plug. By passing the cable under the PSU, they applied enough sideways force to make the contact between the pair of metal fingers intermittent.Jamming something thin between the back of the screen and the cable plug could also have fixed it.

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2014, 05:47:52 pm
content: You get the toaster and iron repair requests here, along with the TV and cellphone requests.

author: Towger
author_rank: Super Contributor
timestamp: June 17, 2014, 06:19:57 pm
content: Re Dave missing the fuse values on the silkscreen.I was presented with a rice cooker to fix on Sunday, sigh.Anyway, upon diagnosing a blown thermal fuse I was left with the problem of reading its near non existent value.Well I am Dave's age and thought I still had good eyesight, when wearing glasses...I could make out the last number and a guess at the others. It was not the font size, but the lack ink. The cookers owner was worse, but showed it to his young lad, he read them straight off. I was left thinking how the #@$@ could he read it, but he was right, it was a standard value even Maplin stocked them!Oh well they say life begins at 40, but I think it is all down hill from there :-)

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2014, 06:25:25 pm
content: 195C right?

author: Stonent
author_rank: Super Contributor
timestamp: June 17, 2014, 07:18:39 pm
content: Yeah, I know. I was just giving him a bit of a hard time. We get to see his videos in 1080P and bigger than real life in many cases where he gets to see regular 1x zoom

author: deth502
author_rank: Frequent Contributor
timestamp: June 17, 2014, 09:09:10 pm
content: loved seeing that half-assed rigging job with that fuse done by a "pro", makes me feel better about some of the amateur shit i do!

author: HyLite
author_rank: Newbie
timestamp: June 17, 2014, 10:05:36 pm
content: That was a spot-on lesson in trouble-shooting technique. Mucho take-away there. Dave's knowledge of what's on the PC board and what it does shows a lot of engineering experience. This guy is one sharp cookie!

author: lowimpedance
author_rank: Super Contributor
timestamp: June 18, 2014, 03:48:12 am
content: Quote from: SeanB on June 17, 2014, 05:47:52 pmCertainly get many requests, but the Aunties toaster was considered an immediate write off not just for the pile of cooked cockroaches in the bottom but also the electrocuted mouse 'stuck' to the mechanical thermostat control

author: rob77
author_rank: Super Contributor
timestamp: June 18, 2014, 03:57:40 am
content: Quote from: lowimpedance on June 18, 2014, 03:48:12 amwas the electrocuted mouse the root cause of the malfunction ?

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2014, 04:50:03 am
content: Probably not, likely the plastic bits it had nibbled on as snacks inside as well.

author: Towger
author_rank: Super Contributor
timestamp: June 18, 2014, 08:21:01 am
content: Quote from: SeanB on June 17, 2014, 06:25:25 pmIt was higher, low 200s. I left it with the owner to source the replacement.

author: VK3DRB
author_rank: Super Contributor
timestamp: June 18, 2014, 01:25:44 pm
content: No mention of an mains safety isolation transformer. All TV techs have them. An ELCB is a poor substitute. Most of these so-called safety switches are trip at way above the lethal current. 10mA CAN KILL YOU. You cannot beat a mains isolation transformer for safety. Use both.A side story: Many ago I bought several hundred 1kW 1:1 mains isolation transformers as new in their box complete with mains plugs for 50 cents each at an auction. An absolute bargain. No-one else at the auction knew what they were. I resold them at at an obscene profit to a distributor who resold them to TV techs around Australia at a price below retail. Everyone was a winner! They would be in numerous repair shops today as essential equipmentAs for auctions and people not knowing what things are, about 3 years ago I missed an auction by 2 weeks... a brand new high end Mantis microscope sold for $230.

author: VK3DRB
author_rank: Super Contributor
timestamp: June 18, 2014, 01:34:33 pm
content: Try a fine pencil rubbed lightly on the flat ribbon tabs then clean with isopropyl alcohol. Then resolder the connector socket pins with higher than normal heat so the longer/higher heat heat flows right into the connector itself. Clean off the flux, even if it is no-clean flux. Then soak the entire connector or board end in isopropyl alcohol for an hour, then blow dry. Your problem might well be solved.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 18, 2014, 02:15:13 pm
content: QuoteDoing so does not necessarily increase your protection - not that using an isolation transformer isn't good advice but it is not a panacea.If you have equipment connected via a transformer and come into contact one point in the equipment you will not recieve a shock because no current can flow to earth - all well and good.If you come into contact withtwopoints at significant potential difference then you will still recieve a shock. Worse the current flow that the GFI/RCD sees will be totally balanced and it will not trip whereas without a transformer enough current might flow to earth to trip the breaker.Also if you connect some point which is normally at a significant potential to ground within the now floating DUT to ground via a 'scope probe lead then areas which are normally safe might wind up at a significant potential relative to ground.By all means power your equipment from a transformer but even then "one hand in pocket" is a good rule to follow. Even better hook up probes with the equipment powered down and keepbothhands off while you power the equipment and take measurements.

author: David Aurora
author_rank: Frequent Contributor
timestamp: August 07, 2014, 01:37:51 pm
content: Picked up the same model today from Cash Converters. They had their clearance pile with a few "broken" TV's, and my sister needed a TV, so I offered them $50 for the two without cracked screens. One seems completely fine unless it has an intermittent issue I haven't seen yet, the other was the Soniq.The cable going up to that small board is an issue in this one too, though this one has WAY messier wiring. Seems to be an interference issue, when I got the cable further away from the power supply it sprang back to life so I just ripped off the tape and zip tied it in place as far away as possible and it was working fairly well but had some glitches still. I guarantee with some shielding I could get it 100%.BUT... Turns out I don't need to. I was just stuffing around with it and as soon as I turned the power saving mode to off, the flickering and glitches COMPLETELY stopped instantly. If I turn on any of the power saving modes the issues come back.So there you go. Get the cable isolated, turn off power saving and all is well.

author: PTSS
author_rank: Newbie
timestamp: March 30, 2020, 05:43:46 am
content: Got one of these Sonic L32V11C on the bench again.Got given it from a mate 12 months back and it had thse exact same symptoms.I spent hours on it, and also suspected issues with the top board or connector.I also some how blew that fusible link!Anyway long story short, is I fixed it back then with actually a Menu setting.Seems this model(s) have a issue with the Energy Saving mode. Turning it off 'fixes' the issue...Ive got it back on the bench as came to use it again after months of storage and it was doing the exact same thing again.I wasted more time on it untell I remembered the 'software' fix. Just tried that again, and it AGAIN 'fixed'Really weird fault!!! I can only imagine this is both a software firmware fault in combination with an issue in theThis video gives you the basics, but the key sequence is wrong.I found it to beHit:1) Stand-by (power up, and wait for 3-5 seconds for it to boot)2) Menu3) Ch+ (Selects Energy Save menu item)4) Source (enters Energy Save Menu Option)5) Vol+ (each press toggles Energy Mode, Standard, High Low, OFF)(found this video later and seems he got the seq correct unlike other videos I found)After this screen stays on and no more flashing.It appears if TV is un powered for along time setting may go back to default and you need to do above again.There seem to be firmware out there, but I can try as dont have a remote control for the unit!I know this old post and prob none out in wild now. But thought I'd post reply as was interesting.RegardsPaulPTSS