Funai (Emerson) LF501EM4F not turning on

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

As you can see the diagram DIGITAL MAIN 5 in post 71, you see the pull-up resistor for the PROTECT3, see what you have both ends of the resistor.

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

https://www.badcaps.net/forum/attach...6&d=1489422823
AL+3.3V is present, right?

3.2vdc is present at J151

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

https://www.badcaps.net/forum/attach...6&d=1489422823
AL+3.3V is present, right?

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

OK, it is VERY IMPORTANT to give FULL and ACCURATE description of DATA.
If your DATA is correct, then I cannot see why you have such low DCV reading on PROTECT3 line since it has 10K pull-up resistor, something is not right, see POST 71.

OKay I looked over what i removed to be sure it was correct there was a very tiny peice of the chip was left where i removed them. I Now get OL reading across ground and protect 3 when main board is unplugged

64kohms if main board +hooked normally Still .5vdc at protect 3 tho either way

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

K OhmS

OK, it is VERY IMPORTANT to give FULL and ACCURATE description of DATA.
If your DATA is correct, then I cannot see why you have such low DCV reading on PROTECT3 line since it has 10K pull-up resistor, something is not right, see POST 71.

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

Protect3 signal route. As you can see, there is pull-up resistor for that PROTECT3 line.

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

31.95 Ohms, K OhmS, M Ohms or what?

K OhmS

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

Does not start tried remote also.

PROTECT 3=
31.95 boards all hooked up not plugged into wall
39.5 if i unplug mainboard

31.95 Ohms, K OhmS, M Ohms or what?

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

So at this point with all the board connected, the TV is still not staring up?
What resistance do you get between GND and PROTECT 3?

Does not start tried remote also.

PROTECT 3=
31.95 boards all hooked up not plugged into wall
39.5 if i unplug mainboard

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

So at this point with all the board connected, the TV is still not starting up?
What resistance do you get between GND and PROTECT 3?

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

PROTECT3 line is connected to pin 7 of all 3 IC through 1K resistor, so if you check the resistance between pin 7 and GND of the IC, it should show high resistance.
"after removing the other 2 pin 7 resistors the protect 3 should test high ?" Yes, when power up the TV it should show around 3VDC on PROTECT3.

No go... all removed R1108 R1208 R1308 Protect 3 still shows .578

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

PROTECT3 line is connected to pin 7 of all 3 IC through 1K resistor, so if you check the resistance between pin 7 and GND of the IC, it should show high resistance.
"after removing the other 2 pin 7 resistors the protect 3 should test high ?" Yes, when power up the TV it should show around 3VDC on PROTECT3.

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

Nope, based on your DATA, your VLED1 power supply is not putting out the boosted Voltage, but the other two do, BUT you are indicating that the Protect3 is still LOW, so I hope your data is correct.

Measuring the protect 3 spots is the same procedure as measuring gate /such ?

ground on same side of board and other lead to protect 3.? I get .5v at each protect 3 test spot. , after removing the other 2 pin 7 resistors the protect 3 should test high ?

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

Do i risk blowing anything else doing this?

Nope, based on your DATA, your VLED1 power supply is not putting out the boosted Voltage, but the other two do, BUT you are indicating that the Protect3 is still LOW, so I hope your data is correct.

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

Something must be wrong with main board, if when ps non forced on pluged into main board 21 v rail is 21 the moment it iis plugged into wall but 11.5 when board alone? or can somehing in led cause

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

One of the three IC is pulling down that PROTECT3, the output n pin 7 is Open Drain output so all three error lines are connected as an OR set up, there is resistor at pin 7 of each IC, you might as well remove them all to see if PROTECT 3 will go HIGH.

Do i risk blowing anything else doing this?

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

One of the three IC is pulling down that PROTECT3, the output n pin 7 is Open Drain output so all three error lines are connected as an OR set up, there is resistor at pin 7 of each IC, you might as well remove them all to see if PROTECT 3 will go HIGH.

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

i think its bout time to give up lol. Was hoping to purchase the main board if anything

[jayjoesph]

Re: Funai (Emerson) LF501EM4F not turning on

If I were you I would remove R1108 (1K) connected to pin 7 (ERROR) OF of IC1101 which is the LED driver for the VLED1, this will stop the VLED1 circuit from pulling PROTECT3 low. You will now have only two sets of LEDS working and the TV should function unless it has more than one problem.

worth a shot.. removed it plugged in main board and full power at rails did not push power no black lights so jumped all besides ps-on protect 3 =.5v

[budm]

Re: Funai (Emerson) LF501EM4F not turning on

If I were you I would remove R1108 (1K) connected to pin 7 (ERROR) OF of IC1101 which is the LED driver for the VLED1, this will stop the VLED1 circuit from pulling PROTECT3 low. You will now have only two sets of LEDS working and the TV should function unless it has more than one problem.