55" Element tv turns on, no picture E4SJ5517BF

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

The backlights will stay on, but only with the panel driver ribbon cable unplugged

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

That's without jumping the power supply

[nomoresonys]

Re: 55" Element tv turns on, no picture

Here's some voltages on the panel board:
vone: .3v
voffe_11: .15v
vcc: 3.3v
(vcc_f_3.3v): 3.3v
(vcc_1.05): 3.4v
avdd: .03v
havdd: .02v
(vcc_3.3): .02v

ok, I must have gotten the thread mixed up, do you get these same readings with tv in standby and after you hit power on?

[nomoresonys]

Re: 55" Element tv turns on, no picture E4SJ5517BF

ok, whatever happened in post 25 was a setback, guess now we need to see if 12 volts is still coming from mainboard out to panel board, can you see if that voltage is there?

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

Ok yes I should be able to check for 12v coming from the main board, as long as I leave the ribbon cable unplugged. Will check when I get home from work tonight

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

Ok so I powered on the tv, with the ribbon cable unplugged. I'm getting 12v at the proper pins on the cable. Also, with the ribbon cable unplugged, I'm seeing weird readings on this fuse and the 2 caps next to it. I'm getting a dead short to ground on both sides of the caps and fuse. I'll probably desolder the caps first and see what happens.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

When I say dead short, I mean my volt meter beeps continuously and the ohms jump all over the place

[nomoresonys]

Re: 55" Element tv turns on, no picture E4SJ5517BF

how is the fuse in diode/continuity mode probe on both ends? ok, de-solder one cap, then check it out of circuit and test the pads where it goes then retest the other one in circuit if short is cleared then you can leave it in place of course. it's usually only one cap that is bad.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

The fuse reads 0 in diode mode, even with the leads switched

[nomoresonys]

Re: 55" Element tv turns on, no picture E4SJ5517BF

000 is good, shows fuse has continuity and should be ok.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

I'll work on those caps in the next couple days and report back

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

Well I desoldered the 2 caps next to the fuse. I still get continuous beeping on both sides of the fuse, when checking to ground, and a reading of 122 ohms. Must be another component farther down the line that's shorted.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

These 6 little holes seem like they might be connected to the other side of the board, in which I could follow that trace. Not sure how it makes the connection without any components going through the board.

[nomoresonys]

Re: 55" Element tv turns on, no picture E4SJ5517BF

need to find the short, did you test all the caps like you did with those 2, one side should beep to ground the other should not, some of your tcon voltages were not right, might have problems with 1 or both of those chips Dskall described. maybe look up the data sheet for those 2 chips.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

Yes I pretty much checked every component for a short to ground. I think there was another group of caps acting the same way as the caps by the fuse...one side would read close to 0 ohms and the other would read around 150. I'll check them again tonight. In post #19, dskall sent a link to a schematic which was close to mine but not exact. If he couldn't find the exact one for my board, I probably wouldn't have any luck.

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

I also have to add that sometimes when checking some caps, the reading would continuously beep on one side, then give a short beep on the other side, but with a low ohm reading...around 100 or just above. Since the components are in circuit, I'm guessing I can't get accurate results

[nomoresonys]

Re: 55" Element tv turns on, no picture E4SJ5517BF

it's very difficult troubleshooting, maybe the key is finding out what component/s are responsible for the tcon test points that are not reading proper voltages, you might not have an easy to find test point for all of them, here is about what they should be: [vdd:3.3] [vgh:20-30] [vgl:minus 5 to minus 12] [vcom:5-7] [von,vgh,vgon,vddg: 20-30] [voff,vgl, vgoff, veeg: minus5-minus9] [vdd, vlogic, vddd, dvdd: 3.3] [vda, avdd, vdda, vsource: 13-20] [vcom: 5.5-8.5]

[Jerdejong]

Re: 55" Element tv turns on, no picture E4SJ5517BF

Ok thanks I'll do some more poking around. First I have to find that short, so the tv will power on with the ribbon cable plugged in.

[nomoresonys]

Re: 55" Element tv turns on, no picture

Here's some voltages on the panel board:
vone: .3v
voffe_11: .15v
vcc: 3.3v
(vcc_f_3.3v): 3.3v
(vcc_1.05): 3.4v
avdd: .03v
havdd: .02v
(vcc_3.3): .02v

yes, besides vcc and vcc_f_, the rest of these are way off.

[nomoresonys]

Re: 55" Element tv turns on, no picture

The group of 4 circled capacitors(pic) measured .45v, but when switching the test leads, they measured 0v. The single circled capacitor(pic) measured 0v, with test leads both ways. The rest of the caps ranged from .1v - 1.8v. All were tested in diode mode.

check the components near the chip in the first picture, be sure to check the transistor and resistor right above those 4 caps.