Lg 19lh2000 lcd (flashing led)

[Liam.25]

Got an lg 19lh2000 here that will not power on, just flashing power led. all caps look fine. i have tested the output voltages here:

They all seem low.

I tested these with just the power plug connected to psu.
15v - 0.8v
15v - 0.7v
gnd - 0.8v
gnd - 0.7v
5.2v - 0.8v
5.2v - 0.8v
gnd - 0.7v
olp - 0.6v
n/f - 0.6v
dim - 0.6v
ilc - 0.6v

anyone ?

[PlainBill]

Re: Lg 19lh2000 lcd (flashing led)

Retest holding the black probe on one of the Gnd pins.

PlainBill

[Liam.25]

Re: Lg 19lh2000 lcd (flashing led)

hi Bill,

15v - 14.84v
15v - 14.84v
gnd -
gnd -
5.2v - 5.25v
5.2v - 5.25v
gnd -
olp - 0v
n/f - 0v
dim - 0v
ilc - 0v

[Liam.25]

Re: Lg 19lh2000 lcd (flashing led)

hope i tested it correct this time.

[PlainBill]

Re: Lg 19lh2000 lcd (flashing led)

hope i tested it correct this time.

Yes, those voltages are reasonable.

PlainBill

[Liam.25]

Re: Lg 19lh2000 lcd (flashing led)

if the voltages are ok, do you think i should have a look at the main board.

[dietzcj]

Re: Lg 19lh2000 lcd (flashing led)

Try this test.
Unplug everything except the power supply and the main board. That would at least eliminate all other components.
i had a similar problem with my 42LG50, the red led would just sit there and blink. the red blinking mean standby.


C

[Liam.25]

Re: Lg 19lh2000 lcd (flashing led)

tried that, still does the same.

its like its trying to power on, it flashes red 5 times then theres a blue flash for a millisecond, then repeats.

[PlainBill]

Re: Lg 19lh2000 lcd (flashing led)

tried that, still does the same.

its like its trying to power on, it flashes red 5 times then theres a blue flash for a millisecond, then repeats.

That sounds more like an error code. Read the service manual.

PlainBill

[dietzcj]

Re: Lg 19lh2000 lcd (flashing led)

THen it is the mainboard.
The mainboard is telling it to shutdown.
If all of your voltages are correct then the mainboard has a problem and needs to be replaced or repaired (if possible).
Just my 2cents.

[Liam.25]

Re: Lg 19lh2000 lcd (flashing led)

Yes you are correct, it is main board.

if both psu voltages are correct, then there is some voltages to check from main board, which i have not done yet. just deciding whether its easier to buy a used board or repair.

i have added the fault diagnosis for my fault.

will kepp you updated on my situation.

thanks

[dennisv9]

Re: Lg 19lh2000 lcd (flashing led)

did you eventually solve it? either repair or replacement of complete mb? i have the same problem, while trying to power (the red blinking) on the voltage reads correct, for a moment i get a blue light (no picture) and then back to standby (solid red). then i only read 5 volt on standy.

i checked the capacitors on the psu, they measure fine (esr and capacity). i did heat the psu with a hairblower (psu), and it momentarily powered on with picture. BUT, i cannot repeat the process, and the psu seems ok.

[amorven]

Re: Lg 19lh2000 lcd (flashing led)

The power board should have +5V and also +15V in stand by

[Timall]

Re: Lg 19lh2000 lcd (flashing led)

I've just been looking at one of these televisions with exactly the same fault, all voltages look much the same and the symptoms are the same.
I found a faulty FET Q302 on the power supply. There is a kit for sale on ebay that includes a 2.2k resistor with the new FET(P2503NPG). The resistor fits between 2 links marked J306 and J310.
I've replaced the FET and fitted the resistor and it's now working.

Perhaps worth checking your TV if you are still fault finding it.