Westinghouse TX-47F430S glowing black screen

[Mr Bill]

This tv popped up on my local craigslist ($20). It turns on but it has a glowing black screen. It does turn off. I'm thinking its a fuse. I checked the 1 fuse on the tcon and it reads good. The main board has aot of fuses. I've run a comb over this board serveral times in the last few hours and every fuse has checked out ok except i can't find this particular one. From the markings on it, sure looks like a resistor to me but i figured i would get a few opinions on this. I tried my hardest to get the best possible picture i could so you guys could see the markings on the board. I ran a pink highlighter over the fuses i've already checked.

Does this "fuse" look like a 330 smd resistor?

Thanks

[budm]

Re: Westinghouse TX-47F430S glowing black screen

Check to see if you do have either 5vdc or 12 vdc at the T-CON fuse.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

Check to see if you do have either 5vdc or 12 vdc at the T-CON fuse.

I'm only getting 11.09v at the fuse on the tcon.

[budm]

Re: Westinghouse TX-47F430S glowing black screen

OK, it does have the VCC, next thing will be to check the LDO regulators on the T-CON board.
Do you have the pictures of the T-CON?

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

OK, it does have the VCC, next thing will be to check the LDO regulators on the T-CON board.
Do you have the pictures of the T-CON?

Here is a quick 12am pic of the tcon

I put a square around the only LDO that i see. Its labeled AME8815, google is telling me its a 1.5A CMOS LDO

**EDIT**
The datasheet tells me its a 2.5v regulator (AECS250). I'm getting 3.276v IN and 2.499v OUT. So i would assume that this is a good regulator.

[retiredcaps]

Re: Westinghouse TX-47F430S glowing black screen

The main board has aot of fuses.

There is one my posts I wish I could delete. I thought FB stood for fast blow fuses. PlainBill, as only he can in his unique style, corrected me .

http://en.wikipedia.org/wiki/Electro...e_designations

FB = ferrite bead.

http://en.wikipedia.org/wiki/Ferrite_bead

A ferrite bead is a passive electric component used to suppress high frequency noise in electronic circuits. It is a specific type of electronic choke. Ferrite beads employ the dissipation of high frequency currents in a ferrite ceramic to build high frequency noise suppression devices. Ferrite beads may also be called blocks, cores, rings, EMI filters, or chokes.

[retiredcaps]

Re: Westinghouse TX-47F430S glowing black screen

**EDIT**
The datasheet tells me its a 2.5v regulator (AECS250). I'm getting 3.276v IN and 2.499v OUT. So i would assume that this is a good regulator.

Yes, a good regulator.

What are the part numbers for UP3 and UP4?

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

UP3 and UP4 are both the same

6900GSM, i've been trying to find a datasheet but haven't had any luck

[budm]

Re: Westinghouse TX-47F430S glowing black screen

IF you look real close at the board, you will see a lot of round copper pad test points with Voltage indicators on the them, see what you get at those test points.
For example, at UP3, at the bottom left corner of the UP3, you will see "V12V" label. So check them out.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

IF you look real close at the board, you will see a lot of round copper pad test points with Voltage indicators on the them, see what you get at those test points.
For example, at UP3, at the bottom left corner of the UP3, you will see "V12V" label. So check them out.

V12V -- 11.09v
V56V -- 2.940v
V33V -- 3.284v
V25V -- 2.494
VAA -- 2.312
VDA -- 2.268
GV OFF -- 2.489
GV ON -- .797
VCOM -- .844
VGL -- .018
VREF -- 2.255

Does it seem likely that the tcon is the issue? One can be picked up on ebay for $21.74 with free shipping.

Thanks

[budm]

Re: Westinghouse TX-47F430S glowing black screen

From what I see on the pattern of how they labeled these test points, it seem to me that the one with V56V should have 5.6V on that test point instead of 2.940V as you have shown (the other test point I.E. V25V read 2.494V which is basically 2.5V). So I think that will be the area to check.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

What would need to be checked? Do you need a better quality picture?

[budm]

Re: Westinghouse TX-47F430S glowing black screen

Now I am not sure you will want to fix down to component level, we will need the P/N on those components, please see the attached pictures and PDF to show you what I think is going on in this board.
The 5.6V power may be bad or it is being loading down too much due to short (not 0 ohm shorts type) by the bad caps, or other components.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

Good point bud. Since a replacement tcon is $22 on ebay, i think i'll just try that route. I'll post results next week when i recieve it.

[budm]

Re: Westinghouse TX-47F430S glowing black screen

That is pretty cheap for 47" TV.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

I use shop jimmy to cross reference part numbers for ebay and this tcon is compatible with 31 different tv models.

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

I received the tcon board today and i did not fix my issue. So the only other option is the main board. I am surprised to see nichicon, rubycon, and chemicon caps on this main board and power supply.

[budm]

Re: Westinghouse TX-47F430S glowing black screen

How about the voltage readings at those test points on this new T-CON board? Do they come up with the same readings?

[Mr Bill]

Re: Westinghouse TX-47F430S glowing black screen

the voltages are exactly the same between the new board and the old one.

[budm]

Re: Westinghouse TX-47F430S glowing black screen

I wonder something in the panel is loading it down, can you disconnect the ribbon cables between the LCD panel and the T-CON to see if the voltage will go back up. I just hope that this new T-CON is a known working board.