Need Help Repairing BN44-00197 board

[Tech 57]

Working on a Samsung LN40a530
Dead subbed another power board so this is the problem.
Changed caps not a cap problem.I just don't know what other component can cause this
I have 12v the 5v line at the plug that goes to the main should be 5v only reading 2.2v
I have other boards here that have the same problem.
Has anyone rebuilt one of these besides the cap problem
Any Ideas other than replacing the board
Thanks ???

[Diah]

Re: Need Help Repairing BN44-00197 board

voltage supply levels. derived from +5v. Ex; 2.5v and 3.3v using
buck regulators.

change IC regulator

[budm]

Re: Need Help Repairing BN44-00197 board

Working on a Samsung LN40a530
Dead subbed another power board so this is the problem.
Changed caps not a cap problem.I just don't know what other component can cause this
I have 12v the 5v line at the plug that goes to the main should be 5v only reading 2.2v
I have other boards here that have the same problem.
Has anyone rebuilt one of these besides the cap problem
Any Ideas other than replacing the board
Thanks ???

Are you saying the DCV for the STB5.3V PIN 3 and the SWITCHED 5.3V (pin 13~16) at the power supply output connector CN801 are only show 2.2V?
The STB5.3V and the switched 5.3V (through SWITCHED MOSFET QM806), and switched 13V (through SWITCHED MOSFET QM804) are generated by the same power transformer TM801 as shown in SCH BN44-00197A, no Buck regulator.
http://www.shopjimmy.com/catalogsear.../?q=BN44-00197

BTW, please upload good clear pictures of the top and bottom side of YOUR board.

[budm]

Re: Need Help Repairing BN44-00197 board

voltage supply levels. derived from +5v. Ex; 2.5v and 3.3v using
buck regulators.

change IC regulator

Sorry, that is not true on this power supply board, see the diagrams.

[Diah]

Re: Need Help Repairing BN44-00197 board

i was talking on DC to Dc on main board.. thanks for the manual as i don't have them.

[Tech 57]

Re: Need Help Repairing BN44-00197 board

fault is the power board main board is good
I put in another power board works fine so the power board is at fault.
still trying to find out the defective part on the power board

[budm]

Re: Need Help Repairing BN44-00197 board

That is why we need to know which 5.3V is low, the STBY or the Switched 5.3V

[Diah]

Re: Need Help Repairing BN44-00197 board

fault is the power board main board is good
I put in another power board works fine so the power board is at fault.
still trying to find out the defective part on the power board

if you have so many power board , and you replace .. just now you asking on fault.. common be more serious.. many here can smell tV smoke from writing.

[Tech 57]

Re: Need Help Repairing BN44-00197 board

@ diah excuse me what are you talking about ?
I'm asking for helpful advise if you don't want to help then don't.
It would be nice if the fault component was found then that would help anyone that ran into this problem.The boards i have are junk and have major problems by lightning so those are trash.
If I can't find the answer I will just have it replaced.
Thanks everyone that was trying to help.

[budm]

Re: Need Help Repairing BN44-00197 board

He probably used the Google translator of some sort to translate German to English so it does not come out quite right.

[ebenedekfi]

Re: Need Help Repairing BN44-00197 board

I have the same board BN44-00197A.
In first stage I changed following caps: CM804, CM806, CM809, CM812, CM810, CM808
Resistor RM851, RM852, RM853 are burnt, i changed it, and I changed the IC ICM802 too.

Now my problem:

Standby voltage 5.3V is OK, if the mainbord is not plugged in, but if plugged in MB the standby voltage become 2.1V-2.3V instable. without MB the power supply starting ok, 13V ok, 12V on inverter ok.
Please help.

Endre