mrobo
Member
Last Activity: 12-16-2024, 04:49 AM
Joined: 11-02-2006
Location: Slovakia
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It is me 😀 -
Re: LG TV 42LW4500 does not starts up LED red white red
does the relay clicks when powered on with remote, then you have probably same problem like me...Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
compared measurements on Q401 same transistor type
-pin1 Base to +pin2 Emitter = infinity
-pin1 Base to +pin3 Collector = 1963 mV
-pin2 Emitter to +pin3 Collector = 1521 mV
reverse measurement:
+pin1 Base to -pin2 Emitter = 628mV
+pin1 Base to -pin3 Collector = 631 mV
+pin2 Emitter to -pin3 Collector = infinity...Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
Today I found the NPN transistor Q405 2SC3052 and measured it on board like diodes with digital multimeter and here are results:
-pin1 Base to +pin2 Emitter = 1969 mV
-pin1 Base to +pin3 Collector = infinity
-pin2 Emitter to +pin3 Collector = 965 mV
reverse measurement:
+pin1 Base to -pin2 Emitter = 627mV
+pin1 Base to -pin3 Collector = 624 mV
+pin2 Emitter to -pin3 Collector = 724mV
for me it does not look like shorted, but not sure if it is good or bad,...Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
Do you mean that voltage from pin2 PWM which jumps from 0,28V to 0,38V is low and should be 0 powered off and 3.5V when powered on?
Even the voltage pin18 DRV-ON (Inverter On/Off) on which I have 0V, should have 3.5V when turned on TV?Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
It seams that all voltages are correct only pin18 DRV-ON (Inverter On/Off) I have 0V, which voltage should it have?Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
today I made some measurements and here are results, look attachment
as you can see when I press power on on remote the votages on column pins2 - PWM jumps from 0,28V to 0,38V then (relay cycles) 0,01V again to 0,28V, any advice where should look next?...Last edited by mrobo; 02-09-2020, 09:09 AM.Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
from the lg service repair process I should go to A19 and A22, but
can someone explain me the attachment
Contents of LCD TV Standard Repair Process Detail Technical Manual A22.png
how to do so?
which is the IN-START button of the remote?...Last edited by mrobo; 11-17-2019, 09:36 AM.Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
correct me please if I am wrong, is this the correct service manual for my tv?...Leave a comment:
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Re: LG TV 42LW4500 does not starts up LED red white red
adding some pictures of the power board:...Leave a comment:
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LG TV 42LW4500 does not starts up LED red white red
Hi, my LG TV LG 42LW4500 stopped powering on one day, when I insert power cord cable to power socket the LED light turns on red color.
When try to power on with remote it changes slowly from red to white (can hear clicking relay) and again slowly from white to red and TV stays off.
Could you give me some suggestions where should I look for problem?
I inspected the power board visual, looked for bad caps but found nothing.
Thx for any help. -
Re: Samsung LA32B350F no backlight
on the transistor QB801 = KTD1347 are the voltages so
E = 0.7V this goes to pin8 which is VCC on UP801 = FAN7530
B = 0.6V
C = 19.2V
the UP801S = FAN7530 does not get VCC on pin8 only 0.6V, then cant give out on pin7 0V which goes to mosfet QP802S = IPA60R600CP 6.1A 600V
does it mean that the circuit with UB802 = KIA393 is not working?
or bad transistor QB801 = KTD1347 ?
or bad UP801 = FAN7530 ?Last edited by mrobo; 05-30-2017, 05:51 AM.Leave a comment:
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Re: Samsung LA32B350F no backlight
I measured the UP801S = FAN7530 with power board taked out, without conection to the lamps
pin1 = 2V INV
pin2 = 0V MOT
pin3 = 0V COMP (but some votage showed 0.03V)
pin4 = 0V CS
pin5 = 0 ZCD
pin6 = 0 GND
pin7 = 0 OUT
pin8 = 0.6V VCC...Last edited by mrobo; 05-30-2017, 12:30 AM.Leave a comment:
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Re: Samsung LA32B350F no backlight
how to measure it is on the other side of board
should measure with disconnected lamps?...Last edited by mrobo; 05-26-2017, 05:24 AM.Leave a comment:
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Re: Samsung LA32B350F no backlight
I cant measure the voltage on pin 4 and pin 5 UM801S = my multimeter starts beeping I have it on 750ACV or 1000DCV
Leave a comment:
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Re: Samsung LA32B350F no backlight
Need advice : I found two diodes on the other side of board, they measured results are strange to me, look at picture
DP802 = KDS184 24mV 26 Ohm both sides!!! (ok they are probably good they have low resistor connected paralel)
DP807 = KDS184 2mV 1.4 Ohm both sides!!! (ok they are probably good they have low resistor connected paralel)
compared to
ZP801 = Z02W6.8VY 534mV PN 25.5 KOhm, which is zener, but seems for me good
I have not much skill in desoldering smds, before I try could you confirm me to continue...Leave a comment:
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Re: Samsung LA32B350F no backlight
Today I made measurements with other digital multimeter tool, with Metex M-3650D (putted new battery into)
I uploaded it in excel, I hope it is clearly now.
I measured all diodes in circuit with nothing bad found, some of them out of the circuit and measured with no problem found, like the
ZM801 .989 PN, 141 KOhm PN
in power circuit:
ZM804 .973 PN 135 KOhm PN
ZD804 .965 PN 135 KOhm PN
ZD803 .965 PN 131 KOhm PN
of course in NP all have open circuit
visually inspected the electro caps...Last edited by mrobo; 05-26-2017, 12:48 AM.Leave a comment:
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Re: Samsung LA32B350F no backlight
It was meant so:
[B][I]pin2. pin7. pin5. = 5,15V
pin4. pin10. pin11. = 13.04V[/I][/B]Re: Samsung LA32B350F no backlight
It was meant so:
[B][I]pin2. pin7. pin5. = 5,15V
pin4. pin10. pin11. = 13.04V[/I][/B]...Leave a comment:
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Re: Samsung LA32B350F no backlight
[COLOR="Red"][B][SIZE="4"]you are in wrong thread !!![/SIZE][/B][/COLOR]
go here
[URL="https://support.hp.com/us-en/product/Compaq-Presario-CQ61-Notebook-PC-series/3938633/model/4043461"]https://support.hp.com/us-en/product/Compaq-Presario-CQ61-Notebook-PC-series/3938633/model/4043461[/URL]
and find yoursRe: Samsung LA32B350F no backlight
[COLOR="Red"][B][SIZE="4"]you are in wrong thread !!![/SIZE][/B][/COLOR]...Leave a comment:
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Re: Samsung LA32B350F no backlight
ok new measuremets (my input is 227V AC I am from EU):
in stand by:
CP815 = 304V
1. Power On/Off = 0,01V
2.7.5. = 5,15V
4.10.11. = 13.04V
12. InverterOn/Off = 0V
13. E-PWM = 0V
14. DET_5V = 0,01V
in powered on:
CP815 = 300V
1. Power On/Off = 0,76V
2.7.8. = 5,14V
4.10.11. = 13.01V
12. InverterOn/Off = 5.1V
13. E-PWM = 2.02V
14. DET_5V = 0,12VLeave a comment:
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