Bush BPDP42HD3

[flocko]

can anyone tell me i have one of these on the bench,red standby light on powers on to green but nothing come up,so i check the supply and am getting ps-on going low from the Av and all small voltages come up but no Va or Vs, on checking Va-on and Vs-on from control board in standby Va-on =5.2 Vs-on =0.00 when powering on the Va =2.3 and Vs=0.00. Am i right in thinking bad control board and can you tell me are there any problems with fitting an LJ41-0839A when the board fitted to this set is a LJ41-0839C or is the end letter just the manufacturer like on Samsung power boards. Regards Flocko

[tw2005]

Re: Bush BPDP42HD3

Well having a quick search for this model it appears to be based on the same Samsung panel used in the 42C450, C430 .

i've fixed one of those and also appears Xmains blow in them. That could be cause the set to go into protection so Vs may not be turned on because of that.

I know it took a replacement ymain and xmain on mine to get it running. can't remember if you disconnect the xmain that may get vsus to turn on or not.

I'd probably check out the heatsinked transistors on both the X and Y for any shorted for a start or maybe check if the Vs is shorted at the connectors on both boards.

with the logic, did you mean LJ41-08392

[tw2005]

Re: Bush BPDP42HD3

Another model you see a few posts on is the RCA 42PA30RQ, also based on the same panel with similar issues

I have read replacing X,Y & buffer board in one go is recommended. Definitely x & Y as I belive the Xcan take out the Y. I got the 3 boards but my buffer ended up testing ok.

maybe try a search on those related models and see what checks or steps you can try.

The logic has a LED that blinks and what that is doing can give a clue if it's in protection or not. I'm not overly up to speed with these but did get mine going.

[tw2005]

Re: Bush BPDP42HD3

could also try a search on the X & Y part numbers ,

my post for what it's worth, also C451 models. they vary the model numbers a little from region to region.

https://www.badcaps.net/forum/showth...ht=LJ92-01736a

[flocko]

Re: Bush BPDP42HD3

Thanks for getting back to me, yes same set just uses a different main board, with the X and y disconnected still no Vs coming up,and also made a balls up it should have read Ps-on from control board not Va, so no VS-on signal from control board, and also left the 2 off the end control board number it should have read as you say LJ41-08392C

[tw2005]

Re: Bush BPDP42HD3

Here's one example, last post has a link for mainboard isolation and testing jumping the logic but if it's in protection I don't expect any change.

https://www.badcaps.net/forum/showth...light=42PA30RQ

[tw2005]

Re: Bush BPDP42HD3

Thanks for getting back to me, yes same set just uses a different main board, with the X and y disconnected still no Vs coming up,and also made a balls up it should have read Ps-on from control board not Va, so no VS-on signal from control board, and also left the 2 off the end control board number it should have read as you say LJ41-08392C

So with the Y connected but x disconnected all power leads( i forget if there's one or 2) still not vsus. It may only come on for a moment and shut off.

One of the other guys will probably have a clearer idea but check the logic LED and note the blinking pattern/interval etc and report that.

[flocko]

Re: Bush BPDP42HD3

With Y and X supply its in a chain out of the power board and in the Y from the Y to the X, control board green Led on for 5sec off for 2sec, i could pull the power board and try to turn Vs-on think it needs to go high but am unsure,looks like Ps-on needs to be low from the Av and control, with no load on the Vs it should stay on if i jump it on ?

[tom66]

Re: Bush BPDP42HD3

VS-ON: logic HIGH
PS-ON: logic LOW

with X- and Y-main out, you should have Vs and Va.

[flocko]

Re: Bush BPDP42HD3

Thank Tom so should having no Vs-on signal on the power supply connector from the logic control board when i power on tell me i have a bad logic board, and if so can i use a LJ41-08392A to replace the LJ41-08392C fitted to this set.

[tom66]

Re: Bush BPDP42HD3

VS ON should go high when it first powers on, but may go low once it goes to 5-2 blink error.

[flocko]

Re: Bush BPDP42HD3

yes it does, hard to check on your own but yes it comes up to 3.45v then drops out,it does this with or without the Y/X cable in the power board

[tom66]

Re: Bush BPDP42HD3

OK, that means it's probably not a control board fault, but X- or Y-main.
Check -Vsc on Y-main, and Ve on X-main.

Ve may not be marked but will be around 80 to 120V.
-Vsc should be around -180V to -200V.

[flocko]

Re: Bush BPDP42HD3

so whats the best way to go pull both boards and check for shorts and go from there whats your bets Yor X

[tom66]

Re: Bush BPDP42HD3

Neither. Check voltages 1st then reply, and then check any/all semiconductors on there for shorts.

[flocko]

Re: Bush BPDP42HD3

it would not power up the Vs and Va so hard to check voltages, but if you had put your money on the X you would have won, both boards out X has Vs dead short,Y all good. Got a board on its way £15.00 thanks for all your help Flocko

[flocko]

Re: Bush BPDP42HD3

the first X sus also had shorts so was returned, then i order both X and Y boards from a bigger seller when they got here they also had shorts and had to go back, i am thinking of giving up on this set, but at least know the power board is fine checked it on the bench by jumping PS on and VS on,

[flocko]

Re: Bush BPDP42HD3

Just an update after sending back two X Sus boards from two different sellers and one Y Sus all showing shorts on arrival,i was able to buy a Samsung PS42C450 with a broken screen and use it as a board donor now have working set and a few spare boards as well

[tom66]

Re: Bush BPDP42HD3

Nice, so it seems that most of the boards on ebay are bad...

[flocko]

Re: Bush BPDP42HD3

I can not work it out. How long does it take to run a meter over a board to check for shorts, They just send them out and you end up out of pocket with the postage to return them. i sell on ebay and if i am unable to test i wont sell, i do get some returns but i know that is because they buy the wrong boards,LG T-Cons are the favourite when they buy by the board layout number but forget the part number then say its not working? rant over Flocko