Samsung LN46A650A1F

[Anzio]

Hello, I'm a new member and first time poster.   I have a Samsung LN46A6501AF that is in a power cycle loop.  The red led flashes 4 times, the music chimes then it repeats the cycle over and over.  I have read the related articles in the LCD forum, replaced caps and all voltages are on power board are correct.  I saw others have shorted pins 5 and 6 on the eeprom of earlier Samsung models to reset it. 

I downloaded the schematics for this model which list the 5 eeproms as IC114.   On my main board BN94-0666K I do see 5 eeproms, one on each HDMI/WISELINK (ICs 401-405), don't see anythng listed as IC114.

Any suggestion or anyone have same or similar problem with this model and can direct me to the correct eeprom so I can try shorting pins 5 and 6 to clear a possible bad eeprom.

-Anzio

[downunder]

Suspect your eeprom will be IC803 [AT24C256] on the underside of the main board....small surface mount 8 pin IC.

Bruce

[Anzio]

Bruce, thanks for your reply.

I shorted pin 5 & 6 on IC803 and it now does not recycle power immediately and chime as before.

When I plug it it, The relay clicks and red light blinks 5 times.  It repeats this again after 40 seconds. There is not standby light on.  When I press the remote keys the red light blinks when trying the factory mode sequence but it will continue to recycle after 40 sec.

I've tried shorting the pins again and if the timing is not right it goes back to the immediate power recycle and music chime.

I've read that it took others may tries to get this to work.  Any other suggestions?

One other note:

Connector from psb to main board.  13.0vm Pins 19, 21 and 22 are actually reading 12.93v, where should I check to see if this is the problem.



Thanks Anzio.

[downunder]

Hi Anzio,
This is what you should do:

Switch off tv and fit a long shorting link between pins 5 & 6 of IC803. Refit main board and turn on the tv.
Within seconds, cut the shorting link and bring the tv out of standby. Access the service menu and execute a reset.

Of course this may not be the problem. Power supply BN44-00203? Do you have a steady standby 5V on pin 3/CN801 and do you get a PS-ON voltage on pin 1 when you turn on from standby? If yes to 5V but no to PS-ON, then main board is faulty.

Bruce

[Anzio]

I have PSB BN-440023 and main board BN94-01666K

When I plug in the power cord to TV the relay clicks, 5 blinking red led, backlight flashes once, ethernet green light flashes once.  The sequence repeats every 40 sec.

Below in parethenses are the readings I get for CN801 on main board. Voltages remain constant except pin 4 MSCL.

1. IR   (3.87v)
2. GND  (0v)
3. A3.3v   (3.28v)
4. MSCL_A5v (1.64v drops to 0.06v)
5. Buzzer (0.0v)
6. Key1 (3.28v)
7. Key2 (3.28v)
8. MSDA_5v (5.18v)
9. A5V (5.19)
10. LED_CTL  (0v)

[fix2003]

BN44-0023

not correct number I think

[downunder]

Thanks, fix2003, I had noted a number missing from the PSU part number.

Hey Anzio, "LED_CTL (0V)" tends to indicate there's no command from the main board to turn on the backlights. I'd expect about 3V at that pin. If you unplug the main board from the power supply board, a lot of Samsungs will turn on with backlights illuminated. If you TV does that, it means PSU and backlights are working fine, and the Main board is faulty. Admit I've no idea what MSCL refers to and I think this model is not particularly prone to eeprom corruption resulting from venting PSU caps.

Bruce

Perhaps this is your PSU?

[Anzio]

Sorry about the typo.  The PSU is BN44-00202A.  I'll try unplugging the main board from the power supply board and report back.

Anzio

[jordan]

BN44-00202A

[fix2003]

Samsung LE46 A BN44-00202A with power supply
•    LE46 is only after repeated clicking of
•    Builds a picture on TV - audio available
•    Status LED lights red
•    Terminates at fault due to longer startup times
•    Cold start after several attempts reboot directly
 Board Name:
•    BN44-00202A

 The following capacitors are most affected:

 Number
 Capacity
 Voltage
 PCB positioning

 2 x
 1000uF
 10V
 CM852, CM853

 2 x
 470uF
 25V
 CM872, CM873

 2 x
 820UF
 25V
 CB876, CM881

 2 x
 47uF
 50V
 CM871, CM875

[Anzio]

Jordan,  thanks for the BN44-00202A schematics.  The first page is fuzzy when I zoom in, however page 2 is perfect (am I missing something?) 

I'm going to recheck the voltages at the test points and components.

Anzio