LG 55LD520 HDMI Problem (No signal)

[curt2199]

I'm using my Fire TV and on the side HDMI (3) I get the center amazon text when it first boots and then nothing but a black screen. On the 2 back HDMI I get "No Signal". The TV recognizes that something is plugged into the HDMI port because I can select the respective port.

I found some similar LG issues that were solved by heating or baking the main board to reflow solder and I'd fixed a couple video cards this way in the past so I gave it a shot. I attempted the heat gun first followed by baking at 385 for 10 minute. Neither resolved the problem. Is it possible there is just a chip that needs replaced? Replacement boards are running around $125 on eBay and that's just not kosher to me.

[CapLeaker]

Re: LG 55LD520 HDMI Problem (No signal)

Chances are slim. The HDMI inputs are going straight to the main IC.

[diif]

Re: LG 55LD520 HDMI Problem (No signal)

385 isn't hot enough to reflow the solder.
I've fixed a couple of LG mainboards giving them a reflow but using an IR rework station.

[Nick's Tvs]

Re: LG 55LD520 HDMI Problem (No signal)

I really don't suggest baking them, but instead actually performing a rework/reball, or replacing the chip itself., otherwise you are only buying yourself a few extra weeks/months to about a year before the board fails again It is possible that the chip could have failed internally in a way that even a reball won't do the trick.
What is the part number of your main board?
Also melting point of solder is about 180 celsius but varies a few degrees dependent on the type. This means if you put it in an oven at 356 farenheit or higher, it should do the trick for a reflow. This means 385 is more than enough and you wouldn't want to go any higher since this is an oven heating up the entire board. If you did go higher you would risk all components on the bottom of the board just falling off. diif is using a ir rework station, you can focus the heat onto one specific spot instead of the entire area of the board, that is why he is able to get away with a bit higher heat.
Just be very careful doing these things, I highly suggest practicing on bad boards as most often if it does not work, you are about to break your board in ways you won't know how to fix.

[diif]

Re: LG 55LD520 HDMI Problem (No signal)

Leaded solder is about 183c but lead free that's on the chip and board originally is about 220c.

[curt2199]

Re: LG 55LD520 HDMI Problem (No signal)

The board is EBR66473904. I can't really tell what chip is handling the hdmi inputs unless its the big XD engine chip in the center of the board with the heatsink.

[dskall]

Re: LG 55LD520 HDMI Problem (No signal)

385f =196c

[diif]

Re: LG 55LD520 HDMI Problem (No signal)

The board is EBR66473904. I can't really tell what chip is handling the hdmi inputs unless its the big XD engine chip in the center of the board with the heatsink.

Yes, the big XD engine is the chip I reflowed after removing the heatsink to about 230c.

[Davi.p]

Re: LG 55LD520 HDMI Problem (No signal)

To Curt: "I get the center amazon text" what is?? A tablet pc??
Why you don't cook some cookies or a pie instead of PCs and TVs? :-)
If you cook also food in that oven you don't have fear that you eat dangerous plastic substances?? Take at least an heat gun..
HDMIs are all connected to a smal 8pin eeprom, this can be bad, you can change it and after you can go to a friend with a similar TV (i never tried) with free Moninfo software, you download EDID data from it then save it an load to your tv, instead of this usually LG pubblish EDID data on their Service manuals, BYE.