Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
I finally managed to get a new main board for this TV and it has fixed it! I now have a brilliant, fully working TV. As far as I can tell, the fault was with IC8000, but I can't confirm that of course. The indications that it was faulty were the missing 12V line, no change of SUB_ON when pressing the on/off button and no indication whatsoever on the front Red LED. Hope this helps someone else and thanks for everyone's input.
baddesley
Engineer
Last Activity: 12-03-2020, 02:26 PM
Joined: 12-03-2012
Location: Romsey, Hants.
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Right, having finally got round to measuring voltages around IC5704, it is clearly not the 12V regulator. However, I have found that this TV uses the LA64 chassis and have found a couple of circuit diagrams for other models that uses the same chassis ( and [url]https://www.electronica-pt.com/esquema/tv/panasonic-esquemas-tv/panasonic-tx-55dx650b-chassis-la64-66216[/url]).
Not exactly the right manuals, but good enough and I can see that IC 5260 is the 12V regulator on the main board. This has power coming in, but...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Hi Diff, thanks for your interest and help. IC8000 is a Mediatek MT5810PEHJ (see photo). This is available for around £25 or so (not in this country though, as far as I can see), but as you say, this is not necessarily the actual cause of the problem anyway.
You're right, this chip doesn't drop the 16V line to 12V itself, it switches it via another chip. According to the description, this is IC5500 (or IC5300 according to one of the drawings!). Having looked at the board very closely, many times though, there is...Last edited by baddesley; 12-12-2019, 12:26 PM.Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
The 12V I'm talking about is generated internally from the main 16V line by IC8000, a large BGA mounted processor type IC. To replace it would need specialist surface-mount soldering and de-soldering equipment, which I don't have.
I have tried re-soldering/replacing these in the past using a standard heat gun and some home-made shielding, but with no luck. Doing this often results in other bits coming of the board and soldering a new one on the board is definitely a skilled job needing the correct tools (I know,...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Well, I'm pretty convinced it's the main/signals board, it looks like the main processor chip IC8000 has failed - no 12V or SUB_ON outputs, whereas everything coming in looks OK. Only a new board now will prove if I'm right or not.
I did find a write-up (originally in Polish/translated: [url]https://www.elektroda.pl/rtvforum/topic3623194.html[/url]) about one of these sets with a failed backlight causing no picture or sound, but that had a pulsing fault code on the TV Power LED (as it should do). Mine has nothing...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
OK, well I think I'm getting somewhere now. Having had a look at the power board circuit diagram, it was clear that my meter WAS reading highly inaccurately (thanks RJ), as the primary caps are directly across a mains bridge rectifier, so my meter was clearly wrong! I've only ever fixed a couple of these types of sets before, so I hadn't assumed this to be the case, but I'm guessing it probably is.
Anyway, I replaced the battery in my meter and re-tested all of the PS voltages and guess what - they were all a LOT...Last edited by baddesley; 12-03-2019, 04:18 PM.Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Great, thanks RJ. Yes, I agree, all of my voltages are measing the same amount out, so maybe it is my meter, though I would have thought the SUB On would have been above 5V by the same amount as well, but maybe I'm wrong there - I've got the circuit diagram for the power board now, thank you very much, so I'll be able to check.
I did search for one, but it all depends on the exact words used doesn't it! Anyway I'll have a good look at that and see where that takes me and will post back tomorrow on how I get on....Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
OK, well I've measured the marked voltages, though I'm not sure how helpful it will be. Maybe my meter isn't measuring accurately, but for the record, the marked voltages measure as follows (with respect to a point marked 'ground') on the 'cold' side.
64V (marked) measures 90V
16V (marked) measures 20V
5V (marked) measures 8.5V
SUN On measures 4V
Maybe there's nothing wrong with the power board after all and it's just my meter and maybe the main board isn't functioning - the IR...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Thanks RJ. I don't think it's my meter, as I've not had problems like that with it before, but it could be that. As I'm measuring across the main caps themselves and because the voltages increase shortly after powering up, I think the voltages are correct, but I'll bear it in mind, as they are ridiculously high, even at first power up, if they are correct!
I've not measured any other voltages yet, due to the worry of leaving it powered up for too long with such high voltages (maybe) across the primary caps. ...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Straight across the caps themselves.Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
It looks like the power control IC could be the small-ish one on the reverse side, near the middle. There's no sign of any blow-out damage, though it could of course just be malfunctioning, but without any voltages to check, this is just a guess. Anybody got any knowledge of these sets and boards before I just order a new power board and cross my fingers?...Leave a comment:
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Re: Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Hi Quaddro, I'm not sure which heatsink you mean, they are all metal and only look silver, or a bit white, depending on how the light is reflecting off of them. I have now numbered the heatsinks in this new photo though.
However, all of the devices under the heatsinks are three-legged devices, so possibly the control device is on the main board? I would expect a contol IC to have at least four pins!...Leave a comment:
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Panasonic TX-49DX600B Dead! TNPA6232 Power Board
Hi everyone, I have just acquired this Panasonic TX-49DX600B 4K HDTV, which is to all intents and purposes totally dead. There is no power LED, no picture or screen brightness, no sound, nor any response to the remote control.
However, there is power on the TNPA6232 power board, mains in, high voltage on the main caps (450V, rising to 600 odd volts - and the caps are only rated at 450V!) and 80V rising to 100V and 18V rising to 24V on the top centre caps. Inititally, the voltages are at the lower figures, then after a minute or so, the higher voltages can be measured, but the TV... -
Re: Baird X47DTV 42" LCD, DTV Tuning Not Working.
OK, thanks, I'll try to get hold of a standard remote and give that a go.
As far as the LCD panel goes, I think you're probably right. However, having seen colour set-up on many people's (perfectly good) TVs, and those in most TV showrooms, I don't think many people know what a good picture is, which is probably how they manage to sell this stuff.Leave a comment:
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Re: Baird X47DTV 42" LCD, DTV Tuning Not Working.
Thanks Tom, but none of those codes work on my set. I don't have the original remote and the one I do have does not have a SOURCE or INPUT button. However, I have tried the SOURCE button on the side of the TV, quickly followed by entering these codes on the remote. I also tried all other obvious numbers (1470, all 1s, 2s, .. 0s), nothing brings anything up.Leave a comment:
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Baird X47DTV 42" LCD, DTV Tuning Not Working.
Hi Guys,
I've been given another of these cheap LCD TVs, which basically works, but has some problems.
The main problem is that the set states that there is 'No Signal' when DTV (Digital Tuner) is selected, despite the fact that my digital signal is very good (works fine & shows good levels on my main TV and DigiBox). DTV Tuning cannot be selected in the menus (it skips this option), so it's impossible to do a channel search. However, Analogue tuning works; it can be selected and searched OK, but, for obvious reasons, does not find anything. Pressing a channel... -
Re: Beko DE2541FS Dishwasher Controller Blown
One last word of warning if you have one of these cheap and nasty machines; The sheet metalwork is very badly finished, or rather, not finished at all and is VERY SHARP on the edges!! This applies to pretty much all of it, even parts accessible to users!
I had to remove the sump on mine, as the seal had worked it's way loose and water was P****** out (can't have been properly fitted from new, as there's no way it could have come out otherwise). Anyway, as I was unscrewing it and trying to get it to drop down - working inside...Last edited by baddesley; 03-10-2015, 05:05 PM.Leave a comment:
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Re: Beko DE2541FS Dishwasher Controller Blown
Redwire, I agree, any sign of PCB burning and the panel should be binned. The burn on my unit was on the the power cable connector to the circulation motor, which had dropped down onto the baseplate and shorted when water leaked onto it. I would recommend anyone with one of these Beko slimline machines to re-position (or cable-tie) this cable above the other cables, so that it can't drop down onto the baseplate - BUT, only if you are confident in doing this & disconnect the power first! When this cable shorted out on mine, it took...Leave a comment:
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Re: Beko DE2541FS Dishwasher Controller Blown
Thanks again STJ. I'm not sure which type mine should be, as I bought a triac and fitted it before seeing your post. I couldn't find a suitable small format surface mount device, but bought an ST T1635-600G 16A 600V D2PAK triac from ebay. Being a larger size, I had to cut away some of the print on the PCB and re-link it to avoid it shorting out, which was not easy, but it has certainly done the job and the machine is now working fine again. The listing didn't state that it was snubberless, but with a Peak Non-rep. Surge Current of 160A,...Leave a comment:
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Re: Beko DE2541FS Dishwasher Controller Blown
Thanks a LOT STJ, that is a geat help!!!Leave a comment:
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