Samsung 933HD not staying on help

[alexanna]

Re: Samsung 933HD not staying on help

The readings changed when i plugged everything in and turned it on, they are as follows;

1) B-Dim = 1.50
2) +15v = 15.44
3) GND
4) GND
5) GND
6) +5.1v = 5.18
6) +5.1v = 5.18
7) A-Dim = 0.70
8) On/Off = 5.02


I have attached some pictures of the logic board, is there any way I can test the voltage regulators?

Your pictures are to blurry to tell a lot.
A voltage regulator should be identified by a “U” designation on the PCB.
They should have 3 legs and a tab. or 2 legs and a stub in the center and a pad.
If you are lucky they may have somewhere in the part number a 33, 25, or 18 those would indicate 3.3volts 2.5 volts and 1.8 volts
The tab is the output voltageThe voltages that you just posted, was that with the monitor working? use the ground Dgtech sugested in an earlier post

[mots]

Re: Samsung 933HD not staying on help

Your pictures are to blurry to tell a lot.
A voltage regulator should be identified by a “U” designation on the PCB.
They should have 3 legs and a tab. or 2 legs and a stub in the center and a pad.
If you are lucky they may have somewhere in the part number a 33, 25, or 18 those would indicate 3.3volts 2.5 volts and 1.8 volts
The tab is the output voltageThe voltages that you just posted, was that with the monitor working? use the ground Dgtech sugested in an earlier post

There are loads of components which have "3 legs and a tab. or 2 legs and a stub in the center and a pad." but none have a "U"

I will take another look at the board later and try and take some more detailed pictures of the board

Is there a way to test each one of these components to see if any is failing?

[alexanna]

Re: Samsung 933HD not staying on help

There are loads of components which have "3 legs and a tab. or 2 legs and a stub in the center and a pad." but none have a "U"

I will take another look at the board later and try and take some more detailed pictures of the board

Is there a way to test each one of these components to see if any is failing?

Yes better pictures would help.
I am not the person to help you test these.
The point I was trying to make is that I have seen voltage regulators do some strange things.
I have noticed them starting out at an acceptable voltage and slowly over time noticing the voltage go low to point things stop working.
Your problem may be difficult to solve because of the fact you sometimes having a working unit. And sometimes non working

[mots]

Re: Samsung 933HD not staying on help

Sorry for not replying for awile but I have got a new power board to test and was waiting for it to arrive - just set it up and it seems to be running fine for the moment so that means it is a fault with my old power board hmmm is it worth buying a new power board or better just to buy a new lcd?

[mots]

Re: Samsung 933HD not staying on help

ok after a few days its the same thing with the new power board

Im just thinking do you think it could be the part in the tv which has to recognize which source is plugged in/ sending a signal to tv that is failing?

Any help at all would be greatly appreciated again - is there anything more i can test?

Thank you

[freecom]

Re: Samsung 933HD not staying on help

same monitor tv.....problems like tv monitor before

turn on very hardly after 5-6 times trying

the best way to start is to warm the main board with hot air


if turn on then all ok for many hours !


probably the problem is in main board

i test all caps with esr meter but nothing.....all caps good

i resolder many items in main bord.....but nothing


100 % same problem like me
http://forums.cnet.com/7723-13973_10...-always-start/

[freecom]

Re: Samsung 933HD not staying on help

my sam ok

solution

reflow with hot air + flux

in main board.....procesor....flash memory....and other


finaly all ok