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Service manuals & datasheets => LCD TV forum => Topic started by: simlock on January 11, 2019,11:52:30

Title: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: simlock on January 11, 2019,11:52:30
Hi, i am a newbie here, and am looking for some help, if anybody can? i have a brand new Sony Bravia 40v5500, it's an old TV now, i bought it and never used it, i took it out the box, plugged in an aerial, and saw it was working, it spent a long time not being used, anyway, this TV was going to be in my room on the wall, but had to decorate first, which i have just got around to doing as i have work commitments, so, my son rings me and said can he use the TV, i said yes, he plugged it in and said it wasn't working, and all we have now is 6 red flashed from the tv, when we switch it on the green light comes first, then it goes to red flashing. any help would be great, thank you
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: Turnip on January 11, 2019,12:32:23
Hi Simlock,

Six flashes indicates a backlight issue, surprising as you haven't used it. It's usually a duff backlight Led, a screen off job.

Admit haven't met the model, just read the service manual, Other folks may have more ideas - Chris.
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: simlock on January 11, 2019,15:27:41
Hi Turnip,

Really appreciate your help, and advice, back light, just wondering if these light area round the edges? i mean, that would make sense maybe, i have had the TV up against the wall for months, perhaps that's how it become damaged? i thought it may have been a sudden spike of electricity, as it was never used, it sounds a bit of a job taking off the lcd, GULP! think i will have a look for a video somewhere on how this is done, just wondering if you can replace these LCD's singaly?, at the moment the tv is in bits, so that will make it easier.

Many thanks
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: downunder on January 12, 2019,02:10:51

This model uses CCFLs for backlighting, pencil-thin fluoro tubes as opposed to LEDs which are more recent. Very hard to physically damage these as they are housed in a cavity behind the display panel. As Turnip says it's likely a faulty CCFL, perhaps one has fizzled out or terminal become corroded during its idleness.


A bit daunting to strip the panel on these. Do it in an orderly manner and perhaps take photos as you go, and it will be do-able. Manual says it could be one of the 2 inverter boards IP1 or IP2, but I've never had a problem with these.                    Bruce
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: simlock on January 12, 2019,04:17:18
Hi Bruce,

Thanks for the reply, i have attached a picture of the TV, i will attempt a strip down today if i have time, can i ask how i test the CCFL's? i do have a fluke metre to hand, the tv has been moved about a bit, but always carefully, and it has never been in a damp environment, and as i said, only ever switched on once, as for the inverter boards? IP1 i think is on the powerboard, but to be very honest, i have no clue what i am doing here. thank you for the reply, it's much appreciated.

 
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: downunder on January 12, 2019,05:00:12
Ah, that's clearer. See the inverter board on the left. Each CCFL is energised by all those small transformers. Put your fluke on ohms and compare the readings on each transformer. Normally they're a match but if you find one that is of different resistance, you're on the money. Even a 10% difference will throw the protect circuit into a spin. It's the high resistance side we're particularly interested in. Also inspect them for poor connections.
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: simlock on January 12, 2019,10:11:58
Hi Bruce,

Yes i thought it best to post a picture up, give you some idea of my model with the back off, ok i know what board it is now, and what to do, i will go through them steadily to see if any are different in OHM's. ill give them a check also as you say to see condition, i have a good magnifier here i bought for work, and let you guys know what i found, thanks for the advice, and how to check. it for problems, really appreciate it.
Title: Re: Sony Bravia 40v5500 red flashing light, 6 times.
Post by: downunder on January 12, 2019,21:01:28

That's a place to start but those transformers may be OK. You'll find a fuse on the inverter - make sure that's OK - and it looks like the board has "fingers" cut into the extreme edge of the board, which slide into the CCFL sockets for contact. Check these contacts on the back of the board to see if any are burnt/charred or otherwise making poor contact.


Maybe then it's time to get serious about the lamps themselves. No real way to test them other than visually. There are CCFL testers, but like LED testers they only supply minimal operating conditions, i.e. they're apt to tell porkies about the true state of the lamps. Don't try to check the inverter outputs with your Fluke or you might need to retire it if output is present - some serious lamp ignition voltages there.                       Bruce