Vizio E500i-B1

[nunoit]

Re: Vizio E500i-B1

update 5 v stand by returned 12/24 v goes to 10v then drops no back lights yet

[CapLeaker]

Re: Vizio E500i-B1

How much voltage are you getting on the main filter cap? Be careful... There are very high voltages there.

[nunoit]

Re: Vizio E500i-B1

thanks for the reply i have been reading the forums. this is what i have found so far.

off primary caps (68 uf), add power rises to 398 then drops to 171.6. power with remote jumps to 398 rock steady. power down by remote drops slowly to 171.6.

history; tv would randomly shut down. i have replaced a few parts already.
IC's 9101, 9301, 9303,9801
replaced R's 9111,9112,9103.
IC 9103 tested like transistor.
ZD9101 tests like regular diode.
tested D9802 Q9801 all smd diodes and transitors. all test good also have removed and tested several caps all good.

terminals
5v | 5v
na | na
1.3|1.3
1.2|1.2
GN|GN
GN|GN
2.9|na
1.6|3.2

i was looking at the 12v loop back circuit and ic 9103 ,and 9102 play an important roll.

[CapLeaker]

Re: Vizio E500i-B1

Usually no 24v means the PFC isn’t working. But you measured 400v so that isn’t it. If your 24v only does 10v, there must be something wrong somewhere.

[nunoit]

Re: Vizio E500i-B1

yesterday i was checking the 12/24v circuit turn on comes from pin #7 through R9301 to Q9102 then through (opto) IC9104 to Q9101 a couple of jumpers to (J9301,9302) to pin 1 of IC9101 (LC703LG) thats as far as i got.

now i see that ZD9101works with Q9101 i need to find what value that diode isto test under load. but i see that IC9101 trys to turn on (10v) then stops it could be the feed back loop that keeps it running at fault.

parts for feed back loop are opto and IC 9103

[nunoit]

Re: Vizio E500i-B1

ok checked voltage to IC9101, feeds are correct, i did not check power to transformer it would only be relevent if it was working correctly.

pin 1 13v dc
pin 16 398 dc

opto load side both pins 1.2 and 1.3 v odd shouldent one side be grounded its the led side.
i think i found the issue. on IC9103 between R and A leads theres a 10k resistor (R9122) that only measures only 8k on board and that has direct control of the GND of IC 9102 opto.

[nunoit]

Re: Vizio E500i-B1

well i have tested just about every component in the 12/24 v circuit and i still dont find the problem the only device i havent changed is the adjustable zener IC IC9103 that resistor R9122 is ok (99990)
i changed the opto IC 9102, i pulled and tested all 4 dobble dodes. all diodes test good

still scratching my coconut on this one.

[CapLeaker]

Re: Vizio E500i-B1

Faulty resistors go 99.9% higher in resistance or open. However there is a 0.1% chance it shorts out. So the 8 k you measured was something else. If you take the resistor out, it will be 10k all right.

[nunoit]

Re: Vizio E500i-B1

i did check and it read 9999 ohms i am going to replace the IC 9103 if that fails then its might be a chip cap i hope not to test need to pull but first need schematic of the circuit to know what goes where.

[nunoit]

Re: Vizio E500i-B1

i ordered new ones yesterday i should get them i a few days then ill bench test again and see from there how it goes.
i'm still concerned with original problem which was would randomly shut down and some times not at at all.

[nunoit]

Re: Vizio E500i-B1

replaced IC 9103 still same thing testing smd resistors in the circuit.
for some strange reason ic 9101 trys to start up then goes into shut down mode its got to be in the r/c network.
i already suspect r9111 (154) reads 69.1k all others so far read good.
going to see if i have another lying around and just change it.

[nunoit]

Re: Vizio E500i-B1

well i found the problem it seems the IC9101 (LCS703LG) one i purchased was bad i replaced it with the old one and now tv is back to working again. now i am testing to make sure the the orignal problem is gone which was tv would randomly shut down.

up date went in to check tv and it was off. with remote i powered back up an checked menu found auto off was set to 10 minutes, i reset to 0 min. testing again.