UA32C6900 continuous restaring

[tiny68]

Re: UA32C6900 continuous restaring

For future reference for others, here are the photos of the full layout of the boards in this TV.
The area I heated on the main board to initiate the change in display response (post#17) was near the antenna input at the bottom and the generally within about 60mm of this. Unfortunately I was unable to work out any more precisely the location that made the difference as the display never reverted to the previous fault image and now I dont have any image at all.

[Davi.p]

Re: UA32C6900 continuous restaring

i can't help you with theese few infos, i can't see by the photos where there is a damage by hot hair, it's up to you, in the mean time you can try the tcon test.

[tiny68]

Re: UA32C6900 continuous restaring

I tested the tcon on the bench (nothing else connected to it). I supplied 12VDC to the input fuse.
The current draw cycled from about 40mA to about 65mA every second (or less). I assumed this should have been relatively stable (I checked a tcon from a similar model which was steady on 70mA).
The test-point measurements were a mixture of stable voltages for some test points and cyclic variation for other test points.
VCC33 = 3.3V
AVDD = (3.3 <-> 1.4)V
VCC12 - 1.2V
VREFU_H = (3.3 <-> 1.3)V
VREFU_L = (2.0 <-> 0.8)V
VREFL_H = (1.6 <-> 0.7)V
VREFL_L = 0.04V
VDDMHL_1 = (1.1 <-> 0.03)V
VCOMS2 = (2.0 <-> 1.35)V
VCOMS1 = (1.1 <-> 0.03)V
F_VCOML (2.0 <-> 0.7)V
VGAMA18 = (0.75 <-> 1.3)V
VGAMA17 = 0V
VGAMA16 = 0V
VGAMA15 = 0V
VGAMA14 = 0V
VGAMA13 = 0V
VGAMA13 = 0V
VGAMA12 = 0V
VGAMA11 = 0V
VGAMA10 = (1.5 <-> 0.7)V
VGAMA9 = (2.7 <->0)V
VGAMA8 = 0V
VGAMA7 = 0V
VGAMA6 = 0V
VGAMA5 = 0V
VGAMA4 = 0V
VGAMA3 = 0V
VGAMA2 = 0V
VGAMA1 = (3.5 <-> 0)V

I assume that this tcon is bad based on the above measurements?

[Davi.p]

Re: UA32C6900 continuous restaring

Tcon not good or in protection because of panel problem, difficult to say , models behave differently, unless you find smps chip datasheet you can't manage to discover this.

[re-atari]

Re: UA32C6900 continuous restaring

For future reference for others, here are the photos of the full layout of the boards in this TV.
The area I heated on the main board to initiate the change in display response (post#17) was near the antenna input at the bottom and the generally within about 60mm of this. Unfortunately I was unable to work out any more precisely the location that made the difference as the display never reverted to the previous fault image and now I dont have any image at all.

Judging by your photo 3, it appears someone has already tried to fix the mainboard. It looks like the left side of IC 2 contains a large blob of solder, where IC 1 does not. See the attached photo, the area in question is encircled in red.
I don't know if this is how it's supposed to be, have no experience with fixing Samsung TV's.

re-atari

[tiny68]

Re: UA32C6900 continuous restaring

Thank for your comment re-atari. After a long delay due to other distractions, I just got around to checking the main board and what looks like solder blob in the photo is a reflection for some flux on the board.

[tiny68]

Re: UA32C6900 continuous restaring

Davi.p thanks for your response.