Baird X47DTV power supply issues

[tom66]

Re: Baird X47DTV power supply issues

Looks like the guy has completely f#*ked up a simple soldering joint.

Remove ALL of the original solder. Use wick not a solder sucker.
Apply new solder. If necessary apply external flux.

[gilly1984]

Re: Baird X47DTV power supply issues

Looks like the guy has completely f#*ked up a simple soldering joint.

Remove ALL of the original solder. Use wick not a solder sucker.
Apply new solder. If necessary apply external flux.

Seems he has burnt the trace too.

Okay to solder from the trace to the fet leg?

Prob less than 2mm.

Could of sworn i had a spare 18n50, any substitute to use? PSU Is only driving the backlights at 6A

[tom66]

Re: Baird X47DTV power supply issues

Should be fine.

[gilly1984]

Re: Baird X47DTV power supply issues

Just thought I would throw this towards you Tom as I know you are on. The shitty job on the soldering is not infact on a mosfet, its on a leg of a transformer??

It looked to me like the mosfet but on closer inspection it was the tranny separating the primary from the secondary side. The tranny secondary leads to the 24v line.

I have done my best to solder it and it checks ok for continuity.

Could a badly soldered leg of a tranny cause the N channel mosfet to short?

[tom66]

Re: Baird X47DTV power supply issues

Could a badly soldered leg of a tranny cause the N channel mosfet to short?

Yes, if the lead is loose, it can cause lots of possible problems. Sometimes just no power, other times it can damage the fets.

Another possibility is the joint is rubbish (from factory or from previous repair) and is probably intermittent, BUT, the main issue has reoccurred (FETs shorting due to inadequate design and poor cooling.)

[gilly1984]

Re: Baird X47DTV power supply issues

Ok Thank you.

Also Tom, while you are still responding to this long Bairded thread.

When you helped me fix my tv last time it worked fine for about a month then died again, same fet and ic blown , so what i did is nicked the fet and ic (They were the same, pri) from the 12v side and replaced the blown ones (on the 24v side, pri) but tv would not switch on, this was because the second psu was not sensing the 12v, so what I did was run a wire from the 12v output on the main psu to the 12v output on the slave psu so the slave seen 12v and would stay on. I then stuck a small 12v fan connected to a 5v output on the psu near the heatsink of the fet that blew again and it has been fine ever since

That explanation is probably crap. If you need a vid explanation let me know.

I am guessing it blew again due to my soldering skills.

[tom66]

Re: Baird X47DTV power supply issues

It probably blew because it's a cheap power supply and underrated to run a 47" LCD backlight.

[gilly1984]

Re: Baird X47DTV power supply issues

and pop goes my new 18n50. soon as the backlights tried turning on it buzzed and popped the fet and fuse. I think the transformer is broke somehow?

bought PSU off eBay instead.

will use this broke one for spares for when mine breaks again.

Thanks again Tom.

[izzycomosy]

Re: Baird X47DTV Psu"

Hi Does anyone know where I can get a Baird X47DTV psu in UK I need one for my tv set
Would be very grateful for a reply.

Thanks in advance

[izzycomosy]

Re: Baird 47"

Ok, i have the tv now,

Plugged it in and no lights no power no nothin.

Open it up and straight away notice a popped cap. (pic 1) 420v 180uf
Thought the big caps never go?

Then i noticed that there was a ribbon cable that links the 2 inverter board that was broken (pic 2), what is that for? Both inverters have there own power from the 2 power supplies.

Also both fuses have been blown, 1 in each psu.

Someone has been in it before as the brown and blue wires have been cut then reattached? See last pic.

Edit;
Yes, i know, my nails are manky.

There was a hole in the back casing, looks like they stuck summat inside and broke that ribbon cable.

Hi do you mind telling me are the both power supply units the same code PSM210-417 as I need to get the one on the left hand side of the main picture of the whole tv. many thanks,tv repair man took the other one and I think he is ripping me off for a £100 plus for the replacement psu. if I can get one cheaper I will fit it myself...many thanks