ITT LCD 32-4000 HDS 2 / Humax 32IS51 Bad Power Supply

[Foppel]

Hi Friends,

i try to repair the power supply from an ITT LCD 32-4000 32" Flat TV with DVB-S2 Tuner. I never plugged the device into the power socket. The seller told me that nothing happens at the TV. So i opened the TV and found a burned chip on the Power Supply. The Label on the chip is: UCC28019 (Datasheet: https://cdn.badcaps-static.com/pdfs/...c4694f2f17.pdf). The SMD Cap C5 seems to be burned. I tested all Fuses, FET's and Power Diodes. They seems to be OK. How can i test the PFC Controller IC1? Should i test other Parts? There are a lot of SMD Parts near the PFC Controller IC1. I have a Multimeter, 30Mhz Oszi, Waveform generator, ESR Meter, Hot Air Rework Station. Any help would be appreciated.

Datasheet IC1: https://www.badcaps.net/forum/showthread.php?t=25603
It is the same model from Humax: https://www.badcaps.net/forum/showthread.php?t=25603

cheers - Foppel

[Foppel]

Re: ITT LCD 32-4000 HDS 2 / Humax 32IS51 Bad Power Supply

I think the Voltage Regulator IC 64 (http://www.alldatasheet.com/datashee...A278R05PI.html) is also faulty. I tested the Voltage Regulator with a lab power supply. It will be very hot after a few seconds without load! Maybe a short circuit between VOut and GND? Can somebody give me an alternative IC Type? It's hard to get this in europe.

best regards - Foppel

[Foppel]

Re: ITT LCD 32-4000 HDS 2 / Humax 32IS51 Bad Power Supply

I changed the following parts:

- IC1
- IC64
- C5 SMD 1uF

The PSU runs perfectly but now i have a problem with the logic board. Maybe faulty caps from Samwha.

cheers - Foppel

[tom66]

Re: ITT LCD 32-4000 HDS 2 / Humax 32IS51 Bad Power Supply

Perhaps whatever killed IC1 also damaged a part on the logic board (main board?)