Samsung LE32B350F1W starting PROBLEM

[saddle_au]

Re: Samsung LE32B350F1W starting PROBLEM

Just adding 2cents worth here.

I would also suspect this regulator because the 5 volt generation comes off the same transformer and the feedback off this goes back through PCM801S opto. The circuit shows either feedback from the 5v or from the unregulated 12v through the opto.

If there was any other instability in the whole circuit, the 5volt line would also bounce around. Also measure the voltage on the feed side of the regulator, is it stable?

Check the feedback resistor divider values and connections. RM864 (10k), RM863 (1k) and RM865 (100R). There should be a stable 1.3volts between the junction of RM863/RM864 and ground pin 3 of the regulator.
Output = 1.3*(10k + 1k + 100R)/(1k +100R) = 13.1v

The output capacitor also needs to be present to ensure stability. CM856 (470uf) and CM857 (470uf), check ground connections (look for solder cracks) and cap values.

Lastly, check ground connection of regulator pin 3.

==========

You can also put in a cheap LM7812 regulator with two diodes from the tab to ground (isolate the tab from ground) to try it, or use a LM317 (isolate the tab from ground) with two different resistor values to set the 13.1v.

[mr.cool]

Re: Samsung LE32B350F1W starting PROBLEM

....sorry but the tab is connected to pin 2 of the LM7812 ?!

[mr.cool]

Re: Samsung LE32B350F1W starting PROBLEM

I tested it with the mc7812.....
And it starts normally !
All voltages are stable !

Now i´m still waiting for the KIA......

[mr.cool]

Re: Samsung LE32B350F1W starting PROBLEM

So my dear friends !
Waiting has ended now !
And the TV is working fine again with the new KIA....

Fu***** LDO

I say THANK YOU to ALL who helped me !
Great Thanks to BUDM and SADDLE_AU !!

[budm]

Re: Samsung LE32B350F1W starting PROBLEM

Thanks for the follow-up, glad that it was just the bad regulator, not the EEPROM or the main board.

[polykarp]

Re: Samsung LE32B350F1W starting PROBLEM

BN44-00289A with soldering problem or main board with 24C512 eeprom problem.

Hi, all there.
I just want share my experience whit this TV.
In my case was two problems.

The first one was that i have no back-light , that was solved by replacing the defective HV transformer for CCFL. I tested the power board an back-light so that i disconnected it from logic(main)board, and back-light was working just fine.

The second was with eeprom 24c512. When i connected power board to main board, tv turns on with that fancy SAMSUNG sound, and after 3-5 second back-light goes off, but tv stays on.
After desoldering the eeprom i not changed it for new one, but erased it with programmer and put it back to main board.
The next start of tv was just fine an tv works again.

[WhiteWolfHellas]

Re: Samsung LE32B350F1W starting PROBLEM

Hi, all there.
I just want share my experience whit this TV.
In my case was two problems.

The first one was that i have no back-light , that was solved by replacing the defective HV transformer for CCFL. I tested the power board an back-light so that i disconnected it from logic(main)board, and back-light was working just fine.

The second was with eeprom 24c512. When i connected power board to main board, tv turns on with that fancy SAMSUNG sound, and after 3-5 second back-light goes off, but tv stays on.
After desoldering the eeprom i not changed it for new one, but erased it with programmer and put it back to main board.
The next start of tv was just fine an tv works again.

I also have the same issue. I replaced the HV transformer to repair the no backlight problem, but after 7 months the TV now has a bootloop problem. I don't see a 24C512 eprom though.

[vinceroger69]

Re: Samsung LE32B350F1W starting PROBLEM

I also have the same issue. I replaced the HV transformer to repair the no backlight problem, but after 7 months the TV now has a bootloop problem. I don't see a 24C512 eprom though.

post 11 has a good picture of the eeprom location

[WhiteWolfHellas]

Re: Samsung LE32B350F1W starting PROBLEM

post 11 has a good picture of the eeprom location

In my board this chip is labeled ATMLH922 2GB 1.
I put it in my RT809H and it is only identified as 24_04. I cannot read it.

[vinceroger69]

Re: Samsung LE32B350F1W starting PROBLEM

In my board this chip is labeled ATMLH922 2GB 1.
I put it in my RT809H and it is only identified as 24_04. I cannot read it.

what is the mainboard number used in your set in post 11 now im on my laptop i can see that their are 4 different 8 legged ics fitted too the pcb

[WhiteWolfHellas]

Re: Samsung LE32B350F1W starting PROBLEM

Ok, I just repaired the TV. The bootloop problem was cold joints on the PSU.

[vinceroger69]

Re: Samsung LE32B350F1W starting PROBLEM

Ok, I just repaired the TV. The bootloop problem was cold joints on the PSU.

Thanks for the update and glad the tv is working again.