Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

[kdaniel]

As stated by the person I collected the TV from, it just stopped working overnight. However, I still gave it a go to try and repair it.

There is a thread on the same TV but with slightly different issues where they had to tape connection points on the ribbon cable, so I want to see if this is repairable by any chance.

After bringing it home and plugging it in, the TV turned on with its backlight working but had no picture. After removing the back cover, the first thing I tried is to unplug one of the ribbon cables and the situation is as follows.

Left ribbon unplugged: Lines on one-third of the screen (from bottom)
Right ribbon unplugged: Image is good and no lines across the screen
Both ribbons in: Full image but with horizontal lines across the bottom third of the screen.

Just to clarify when I first turned the TV on, there was no image at all. After unplugging the ribbons and plugging them back the image came up with the issues listed above.

I've seen similar issues and the most common root of the problem is a faulty screen but I'd be interested if someone had something similar and managed to fix it.

Could it be a ribbon cable or the T-con board or is the problem definitely related to the screen? What are the next steps I should take?

Thank you in advance.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

could be a tcon problem, maybe try cleaning ribbon and lvds cables and connectors with isopropyl alcohol, not to vigorously, they can be delicate, make sure they are not damaged and lined up properly, had these similar lines on an older tv recently, was a bad tab bond, "fixed" with a shim.

[Biruslapio]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

just serviced one 4k tv with garbage AUO panel that had almost this exact same issue, internal panel short. Where the horizontal lines originate the panel was frying hot at 90C+ and even melted a bit of the plastic coating near it.

The image came back very nicely, this was done by taping vgh and the clock lines, outer edge of the ribbon cable, you'll have to trial and error or look at the pinout.

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

The image came back very nicely, this was done by taping vgh and the clock lines, outer edge of the ribbon cable, you'll have to trial and error or look at the pinout.

Could you guide me/explain on how to locate and recognise pins?

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

"fixed" with a shim.

Correct me if I'm wrong, you placed something at the back of the ribbon cable just to pry it down better with the tab?

[Biruslapio]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

try taping these or some of them.
just normal transparent thin tape, no extra pressure.

oh I switched the sides, in your case it's R that needs attetion.

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

try taping these or some of them.
just normal transparent thin tape, no extra pressure.

oh I switched the sides, in your case it's R that needs attetion.

I assume I need to tape only a single line or a few at the time should be fine? Just want to make sure I am doing it right.

So far I've taped pins 13,14,15, starting from the right, together which "improved the lines" but I will carry on and keep you updated.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

Correct me if I'm wrong, you placed something at the back of the ribbon cable just to pry it down better with the tab?

Yes exactly, was easy to determine the fault by pressing lightly on tab bond, but takes some tear-down to get to them, when it was the tab bond at issue it was usually the first or last one, meaning one of the end ones.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

example there: https://www.youtube.com/watch?v=xHst...teY5Gw&index=3

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

try taping 5 or 6 lines from the second pin so maybe pins 2-6 or 2-9, maybe 2-9 then un-tape one pin at a time, try one end if no joy try it on the other end of the cable, same cable just the other side.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

actually you have lines across the whole screen, not just bottom 3rd.

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

actually you have lines across the whole screen, not just bottom 3rd.

Honestly, looking at the TV in person they are not visible, but now looking a bit better at the images, yes, they do show up slightly more. However, the top part of the image seems fine with both ribbons in.

My thoughts are really mixed up looking at the screen for this long.

Do you think that only one screen ribbon could affect the whole screen? I'll probably just take off the frame now and inspect them closer. I was messing with and taping white LVDS cables till now...

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

in my case yes, had those exact looking evenly spaced lines on whole screen but only one tab bond was not getting contact, some as in the video use the shims on all the bonds, I suppose in case any of the other tab bonds get the same idea to become loose, I just did my right corner one as it was the only one loose.

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

example there: https://www.youtube.com/watch?v=xHst...teY5Gw&index=3

So after removing the frame just enough to inspect all ribbon cables going to the screen, I am leaving pictures of what I found.

I cannot determine exactly what it is but it looks dried up and just slightly sticky when scratched.

Closer inspection of all ribbons didn't show any physical damage such as tears or breaks and when I press each one of them down nothing really changes.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

I have also had this exact symptom when the tcon was bad.

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

hmm, doesnt look good, prolly water damage or another bad decision to use cleaning fluids on the panel which dripped down and made a destructive mess.

[kdaniel]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

I have also had this exact symptom when the tcon was bad.

I guess my next step is to try a replacement T-Con. Listening to it, it has some weird buzzing sound and I might be crazy to say this but with the speed and consistency of buzzing, I can see the same consistency in the image. It's like a 1-to-1 ratio.

[Biruslapio]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

have you tried the suggested tape method?
t-con has buzzing because the panel side driver is defective, internally shorted and drawing abnormal current, if only the good side is plugged in and you do not get buzzing, it's the display.
if panel ribbons were the problem you would have vertical lines/stripes, although that one in the photo doens't look great, looks like it has some grime in it, but hasn't been damaged yet.

[Davi.p]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

don't buy tcon, don't waste money..100% only panel damaged.. only signal masking can quiet bad part of screen..

[nomoresonys]

Re: Hitachi 58HK6100U - Horizontal Lines (Bottom third of the screen)

There's a very old adage: Only fools are positive. Testing is the only way to rule things out, NOT a positive guess. I stated I have seen a few different things that I have seen cause this symptom, THAT is a FACT.