VIVO PTV43HD no PS-ON signal

[dkneyle]

These were a badge engineered TV sold by Dick Smith Electronics in Australia. Inside all Samsung parts. Maybe somebody can recognise the actual model?

There is no PS-ON signal being generated by the mainboard. When the PS-ON signal is jumpered to earth the power supply fires up and all voltages are spot on (Vs, Va, Vsc etc).

The mainboard had some sort of brown goo on it (as shown in images). Has the consistency of contact adhesive. No signs of any spill on the external back cover. I couldn't shift it with methylated spirits; I had to resort to carefully removing with a very small blade screwdriver. Anyway, that didn't change the situation.

So any hints to progress from here. Do people agree it appears to be a failed mainboard? I can get a secondhand mainboard for about A$100.

The TV appears to be 2012 model, and it's in very good external condition. I'm reluctant to canabalise a good looking set, but then again it needs to be economical to repair.

[dick_barton]

Re: VIVO PTV43HD no PS-ON signal

The board number T.MSD306.9A 10331 appears when googled to be a generic number used in Bush & Technika.

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

Thanks Dick. Yes, I too Googled the board number and saw the overseas models it is used in. Main boards tend to be country specific even when they have the same model number. In Australia we don't use the scart connector and instead they bring out rca sockets. The firmware seems customised for our channel allocations etc. I can only see one main board for sale here in Australia, from a seller I've dealt with before. I might have to see if I can negotiate the price down to make it economical.

[dick_barton]

Re: VIVO PTV43HD no PS-ON signal

Yes I saw one on sale Australia which was very, very expensive.

[dskall]

Re: VIVO PTV43HD no PS-ON signal

I have a PN43D450A2D looks a lot alike. Different mainboard.

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

Yes, I agree. It certainly looks like the PN43D450A2D in sheep's clothing. The mainboard in my Vivo appears to be configurable for a range of TVs, including LCD models.

[dskall]

Re: VIVO PTV43HD no PS-ON signal

Have you checked to make sure the mainboard is receiving input from remote/buttons?

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

Mmm..now that's a good question. Any quick thoughts about how to test that? I worked on that small board yesterday because it was very mobile and I found many plastic tabs were broken. I've glued it into the plastic frame it is meant to be supported by and I'm happy that the buttons are clicking OK. I note it has only three wires going to it so there must be some sort of multiplexing going on? It did cross my mind as to whether the turn on signal was coming from the front panel switches. I've been slack and haven't tried the remote control. I think I have it with the rescued TV (it came from the local landfill site and people often bring in the remote with the TV).

[dskall]

Re: VIVO PTV43HD no PS-ON signal

Should get voltage changes on one or two wires when you push buttons

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

Thanks to TW2005 I've been able to confirm via the test pattern test that the panel is operational along with all associated boards. So it does appear to be mainboard, and I'm very suspicious of that brown goo I first saw on the board.
Does anyone know if Samsung maainboards have a history of failing and whether there is a repair pathway? By the way, I'm still to check the on-switch for voltages back to the mainboard. Will report any findings of interest.

[tw2005]

Re: VIVO PTV43HD no PS-ON signal

I think it's worthwhile cleaning all thatbrown muck away. Looks like glue that has gone off, may have turned conductive. I just finished getting a Projecta IC5000 battery charger going again, the glue in that was yellow like contact glue which had turned black and corrosive.

Etched the board away and ate the legs off an optocoupler and corroded a Viper22 plus diode.

May need acetone or carefully chip away at it, looks a bit nasty

[dick_barton]

Re: VIVO PTV43HD no PS-ON signal

It's good to see the manufacturers are still ensuring failure by the addition of these glues which are now known to become conductive over time.
This has been discussed many times on the forum so surely if we know, then they know.

[tw2005]

Re: VIVO PTV43HD no PS-ON signal

It's good to see the manufacturers are still ensuring failure by the addition of these glues which are now known to become conductive over time.
This has been discussed many times on the forum so surely if we know, then they know.

That was a $750 AUD, 50 Amp charger in 2014/15. In-laws are pretty lucky I have half an idea.

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

I scrapped most of it away but couldn't find a solvent to shift it. I have acetone, guess there's nothing to be lost? I'd considered using acetone but was concerned about potential damage. Those very small SMT components near the red socket are covered in the stuff and it's difficult to see if they are damaged. Anyway, I think from what Dick says, especially about it being a point of often discussion, then I have my smoking gun. Mxmee (seller of reclaimed boards here in Oz) is offering to lower the price of a mainboard to A$80 plus postage. I need to find a buyer before I can justify the repair, unless I can get the mainboard going again.

[dick_barton]

Re: VIVO PTV43HD no PS-ON signal

From what I've seen Shopjimmy uses acetone for clearing the flux away after soldering so I cannot see that it would be a problem using it on your board. Try it on a small area and see if it can remove the glue.

[vinceroger69]

Re: VIVO PTV43HD no PS-ON signal

I have not really worked on many plasmas so may be a stupid question but do these mainboards have eeprom on like lcd mainboards do as when they get corrupted etc it can stop the ps on signal etc.

[dick_barton]

Re: VIVO PTV43HD no PS-ON signal

The mainboard model appears to be near identical for both the lcd and plasma sets so I would suspect that they also have their EEPROM problems.


https://spares2repair.co.uk/bush-bpd...sd306.9a-10331

[vinceroger69]

Re: VIVO PTV43HD no PS-ON signal

maybe worth freezing it then with proper freeze spray if set starts up ok maybe remove ic and freeze again and to read ic data and reprograme one.

[maxvalutech]

Re: VIVO PTV43HD no PS-ON signal

Doesn't seem any doubt on mainboard at fault but that is a strange number. The Vivos I had 2 plasma all had Samsung board numbers LJ....... or whatever. My view is a going set not worth more than $99 and what warranty can one offer!

[dkneyle]

Re: VIVO PTV43HD no PS-ON signal

Thanks maxvaluetech and others for your input. Will have a go tonight at trying to remove any remaining glue contamination and see if I can detect any residual damage when looking closely through a mag glass. I agree that it can't be worth more than $90 in going condition.