Lg TV Repair: Common Faults and Solutions.

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Lg Repair Guide: Common Issues and Fixes

Brand	Model	Fault	Detailed Problem
LG	STUDIOWORKS 440	League normally, works for hours	But suddenly it turns off by itself (without anyone touching it). This monitor has a regulator that feeds the filament, due to the high amperage it releases the solder, and just resolder it, it is close to the power supply transformer.
LG	STUDIOWORKS 440 NÃO LIGA	The LED doesn't even light up	When checking the power supply, I found that there was no voltage in the secondary of the transformer; I went directly from strf 6653 and verified, through the diagram, that the reference voltage was missing on pin 4, coming directly from the rectification input (this voltage is responsible for the initial start of the strf). When desoldering this pin 4 of the ci, I verified that the voltage close to the alternating network voltage returned to this point. I measured the resistance of this pin in relation to pin 5 and found a value much lower than normal for a new component. I replaced the strf and the monitor worked perfectly again.
LG	STUDIOWORKS 440	When the LED turns on, it turns amber (orange).	Transistor q 451, it was leaking, I replaced it and the amber situation (orange LED) ended, the LED turned green again and the monitor is now being tested
LG	STUDIOWORKS 440	The monitor would turn on and after a few minutes or even hours the image would disappear, but the LED would remain green when pressing the on/off switch, I could hear the power supply arming perfectly but there was no high voltage	I replaced the flyback: it didn't solve it I replaced the tda 4858: it didn't solve the voltages were low and the +b was very high at around 250v, due to it not being oscillating, negative voltage at the base of the tsh around 0.04 millivolt. note: after opening, the monitor burned the tsh and even putting another one didn't solve it. solution found: after hours of searching I discovered the 2sc200 transistor open in position q721, behind the driver transformer. note: I put in its place a 2sd667 taken from scrap I don't know if this is correct, but the monitor is working perfectly
LG	STUDIOWORKS 440	Turning off by itself and shaking horizontally	Cold welding horizontal circuit.
LG	LG19P995E CHASSIS CA84	He sets it up, it's high but it doesn't light the tube	The power supply secondary voltages are normal, there is 125vdc at the +b of the fly and 90v at the tsh collector. it was the video proc ci
LG	LG 57M-CA 46	Monitor is too wide. The controls work normally in all resolutions, but when they are at their minimum width, they still have excess width.	After searching the entire circuit wide and finding nothing, I observed that the 12v power supply was 14.5v on pin 8 of ic 503 (kia 358) h. size, I went there to the outlet responsible for the 12v (ic 903) and found the diode d 916 was shorted, this thing gave me a bigger headache. (problem solved)
LG	LG 57M-CA 46	Monitor that is disarming the high power supply	I verified that the +b has a very high 260v and it keeps arming and disarming. After many tests looking for the defect I realized that when I turned it on, the filament didn't light up and sparks came out of the crt board. I disconnected the 6.3v from the crt board and measured it was normal. But when I connected it to the board it dropped to 3v so I decided to change the tube and it started working normally again.
LG	LG 44M STUDIWORKS CHASSIS 32	When starting the computer, the boot and extended memory sign appears normally, but when starting Windows, the screen is white without any image	The c.i. 202 ( gvc 08001 ) was defective. After a long search, I finally found a used one. After replacement, the monitor started working normally again.
LG	LG 20	Security system discharge but no image	I was about to buy the fly but I discovered a swollen capacitor connecting the pins of this fly and I replaced it and great.
LG	LG 14"	No image, very low flyback supply voltage b+	It was found that the flyback had a short in its primary and the capacitor c721 and the resistor r726 were damaged by the internal short of the flyback in the abl circuit. The flyback and capacitor were replaced, and everything started working normally again.
LG	FLATRON 795FT PLUS-FB795CU	It is 4 mm on both sides, after 20 minutes of use the image is correct	Some customers have noticed changes in the horizontal part of the monitor. changes r706(rn 15kΩ ==> rd 15kΩ)
LG	FLATRON 775FT-FB775CEA	Video card (voodoo) causes problem (the sync signal is cut).	First, check if the identification label (model no) is fb775c-ea, fb775c-ep, fb774c-ea and fb774c-ep. then check if the c744(0ce107cp630 capacitor,100uf 160v) is in good condition. if not, change c744 as the same part(0ce107cp630) change r412, c404 as following (part position -> next to micro r412 : 5.1kΩ --> 10kΩ c404 : 220pf --> 47pf
LG	FLATRON 775FT-FB775CEA	Flicker appears at the top of the screen repair procedure	First, check that the label identification is fb775c-ea, fb775c-ep, fb774c-ca and fb774c-cp. then modify c605, zd601 as below: c605 : 224j --> 154j cf. C605 is the existing form 6870T281A11(PCB board). zd601: 5.1b --> 5.6b
LG	561N/560N/560A	Lackluster lack of definition focus	Replace o fly-back
LG	1470	Width and pad controls don't work	Change q709
LG	1470	It didn't work	After making some repairs to the primary power supply, it is working, but the image is completely dark and bluish. I was suspicious of the image tube, I changed it, but it didn't solve it. So I checked the entire g1 line and found a shorted diode d322, on the kinescope board, but it didn't solve it. I replaced the tda 4882, and everything went back to normal.
LG	1470	Dead	Green LED lights up switch flyback
LG	1470	It turns on but does not show high voltage and has a buzzing sound	Check the fly-back 6174z-2001a it usually makes this type of defect. When you change it, change the c723 together. Capacitor c 723 open. Replaced and started working again.
LG	1470	No image, very low flyback supply voltage b+	It was found that the flyback had a short in its primary and the capacitor c721 and the resistor r726 were damaged by the internal short of the flyback in the abl circuit. The flyback and capacitor were replaced, and everything started working normally again.