Lg - 32lh3000, 32lh5000 - dead no output

[Hamie]

Fixed a couple of these, couldnt find a thread on them. Both failed the same way.

Powersupply: EAX55176301/12

Symptom: dead no 5v, both fuses ok.

Check ZD501 (3.6 Zener) R501 (2.2ohm 0.5w resistor) IC500 (ICE3B0365J)

usually zener, IC are shorted and resistor OL or very high.

replace zener, resistor and IC500 (ICE3B0365J)



Schematic attached.

[adjuh28]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Hallo Hamie,

Thank you for sharing your schematic and fix.

Mine has the same problem and i couldn't trace back the 5v problem.

This helps alot !

[Hamie]

Re: Lg - 32lh3000, 32lh5000 - dead no output

No probs. fixed another one of these since then.
Same issues. Also worth checking c202 as was bulged on my most recent one.

[Chungalin]

Re: Lg - 32lh3000, 32lh5000 - dead no output

I have a LG 32LD320 right now that uses this same PSU (LGP32-09P), same symptoms and same bad components. Always good to find a repetitive fault, thanks a lot!

Will be useful if other posters add other LG models carrying this power supply.

Thanks for the schematics too. It's annoying that some service manuals ommit schematics for power supplies, assuming that any failure there implies a full board replacement. It works this way in official services, but what about others? What about when out of warranty?

[Chungalin]

Re: Lg - 32lh3000, 32lh5000 - dead no output

What about replacing ICE3B0365J with a ICE3BR0665J ? It's more powerful, and I have several sitting here. Same pinout, except for pin 1, but doesn't seem a different meaning.

However, I've just found an ICE3B1565J which only differs in Power (higher) and Rds on (lower).

[Chungalin]

Re: Lg - 32lh3000, 32lh5000 - dead no output

I eventually ordered a ICE3B0365J and I left experiments for another day.

Replaced all 3 components (switching IC, zener 3.6V (1N5227B) and resistor) and the TV is working fine. Good thread!

[SmartSarah]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Great!
As soon as I discovered R501 to be open, I stopped diagnosing and replaced parts.
Job done! Won a lot of time thanks to this thread!

[rodnah]

Re: Lg - 32lh3000, 32lh5000 - dead no output

digging up an old thread, I have replaced the 3 common parts that were shot, however I'm getting a high pitch squeal and cant seem to pin point it.

some help please?

[agerksic]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Hi guys. Found this one as I have a similar problem. Thanks to this thread I changed the parts mentioned above and so far I managed to recover 5V on the output. Still I have a problem with 12/24V output.
I would appreciate it very much if someone has any idea where to look.

Thanks!

[MARHD]

Re: Lg - 32lh3000, 32lh5000 - dead no output

agerksic

Did u ever figure out why u weren't getting 12 and 24v, i also just replaced the components recommended above, and now I have 5v but no 12v or 24v

[dick_barton]

Re: Lg - 32lh3000, 32lh5000 - dead no output

With the power supply disconnected from the mainboard use a 1K resistor between +5V and Power-On (schematic given above) and then switch on and check the 12 & 24V supplies are there.

[MARHD]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Sorry I didn't see your post when I made this thread https://www.badcaps.net/forum/showthread.php?t=70584

I tried what you suggested and i now see something a bit more promising, the 12v pin is showing something more like a weak 8/9 volts, however i get nothing on the 24 still

[dick_barton]

Re: Lg - 32lh3000, 32lh5000 - dead no output

With the set powered off use your meter set to ohms and measure the 24V line to chassis and give the reading and then on the 12V line to chassis and give the readings.

With the set still powered off set your meter to diode mode --!<!--- and measure D251 (red probe on A , black on C then red probe A1, black on C) then reverse the meter leads and again measure black probe on A, red on C, black probe on A1, red on C.
Repeat for D254, D252, D256, D255
Give the readings

[MARHD]

Re: Lg - 32lh3000, 32lh5000 - dead no output

The restance of the 12v was around 1.5meg ohm, and the 24v was fluctuating but roughly over 1.2k ohm.

D251 - continuity with every orientation
D254 - not installed on the board
D252 - continuity with every orientation
D256 - not installed on the board
D255 - continuity with every orientation

I feel like having continuity with every orientation is bad

[dick_barton]

Re: Lg - 32lh3000, 32lh5000 - dead no output

The resitance of the 12v was around 1.5meg ohm, and the 24v was fluctuating but roughly over 1.2k ohm.

Those readings appear to be OK

D251 - continuity with every orientation
D252 - continuity with every orientation
D255 - continuity with every orientation

I feel like having continuity with every orientation is bad

Remove each of them and test them again with your meter set to diode mode. If continuity remains then they need to be replaced.

[MARHD]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Ok i have tested them out of circuit, and they seem to be working. I also tested bd101 and it looks good.

Not sure what to do next

[dick_barton]

Re: Lg - 32lh3000, 32lh5000 - dead no output

With the meter set to diode mode the diodes should measure OL in one direction and approximately 0.5 or less in the other direction. Did they?

Also with the set powered up and power supply not connected to the mainboard, using the 1K resistor from 5V to Power_On what DC voltage do you have between the two legs of C607 or C608?

[MARHD]

Re: Lg - 32lh3000, 32lh5000 - dead no output

340v across C607 and C608, and yes in one direction they were OL and in the other roughly 0.35

[Antonisjr]

Re: Lg - 32lh3000, 32lh5000 - dead no output

Hello,
I have the same symptom: dead no 5v, both fuses ok.
The components mentioned above seems to be ok, but just in case i have replace IC500 with no success 5V is missing.
Any help?

[jespeleo]

Re: Lg - 32lh3000, 32lh5000 - dead no output

hola a todos compañeros desde Córdoba España, tengo otra fuente igual y con los mismos componentes dañados, material pedido, espero que cuando los coloque todo sea ok, ya informare