Hello. I have an Emerson lcd set and it won't turn on with remote or button board on set. It shows a solid red standby led. I suspected the eeprom(N10) so I replaced it but still same results. I still suspect the main board as the culprit, please correct me if I'm wrong. If it is the main board could antone direct me to repairing it? Thanks in advance.
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Emerson LTDN42V68US Red Standby Only
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Re: Emerson LTDN42V68US Red Standby Only
Normal Power Applied
1.88v 1.89v (1)m5v
1.89v 1.89v (2)m5v
0.00v 0.00v (3)gnd
0.00v 0.00v (4)gnd
0.01v 0.01v (5)sw
1.87v 1.86v (6)brt
0.00v 0.00v (7)gnd
4.20v 4.20v (8)12v
4.21v 4.20v (9)12v
5.267v 5.267v (10)s5v
5.267v 5.267v (11)s5v
3.919v 3.919v (12)stb
0.00v 0.00v (13)gnd
0.00v 0.00v (14)gnd
12.42v 12.45v (15)12v
12.42v 12.45v (16)12v
0.00v 0.00v (17)gnd
0.00v 0.00v (18)gnd
4.33v 4.35v (19)12v
0.001v 0.001v (20)gnd
2.045v 2.055v (21)m5v
0.001v 0.001v (22)gnd
0.001v 0.001v (23)gnd
2.055v 2.065v (24)m5v
2.065v 2.075v (25)m5v
0.001v 0.001v (26)gnd
0.001v 0.001v (27)gnd
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Re: Emerson LTDN42V68US Red Standby Only
I see at least one bad cap C929 and maybe C945, 2200µf/25v but these are for the +12v supply. The M5v is low but that voltage is switched by V924 so check that you have +5 volts on jumper wire W914. If the +5volts is ok, try changing C937 (1µf/50v) If the +5v is low it could be that C935, C936 & C938 are also badLast edited by R_J; 06-23-2020, 05:57 PM.
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Re: Emerson LTDN42V68US Red Standby Only
Originally posted by nomoresonys View PostTry test #3 below, try to do it just as directed, pin number, pin description, voltage both off/standby and when power is applied.
1.88v 1.89v (1)m5v
1.89v 1.89v (2)m5v
0.00v 0.00v (3)gnd
0.00v 0.00v (4)gnd
0.01v 0.01v (5)sw
1.87v 1.86v (6)brt
0.00v 0.00v (7)gnd
4.20v 4.20v (8)12v
4.21v 4.20v (9)12v
5.267v 5.267v (10)s5v
5.267v 5.267v (11)s5v
3.919v 3.919v (12)stb
0.00v 0.00v (13)gnd
0.00v 0.00v (14)gnd
12.42v 12.45v (15)12v
12.42v 12.45v (16)12v
0.00v 0.00v (17)gnd
0.00v 0.00v (18)gnd
4.33v 4.35v (19)12v
0.001v 0.001v (20)gnd
2.045v 2.055v (21)m5v
0.001v 0.001v (22)gnd
0.001v 0.001v (23)gnd
2.055v 2.065v (24)m5v
2.065v 2.075v (25)m5v
0.001v 0.001v (26)gnd
0.001v 0.001v (27)gnd
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Re: Emerson LTDN42V68US Red Standby Only
Yep, switch out at least that bulging cap, then try it, suppose if you wanted to be a little more proactive you could change out all the caps in that area, some folks would change out all the electrolytic caps on the board.Last edited by nomoresonys; 06-24-2020, 02:06 PM.
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