Hisense 58H6550E - Freezes/Won't turn on

[tmhobadcap]

I have another tv to fix for my friend. It is a Hisense smart tv. After turning on, it will freeze or stuck on certain screens. However, when it is connected to a tv box, it will automatically connected to it and play without any problem. I wanted to go to the menu and reset the tv. But it just freezes before I reach the reset menu. I have tried the hard reset methods, but no luck. I guess the main board is with problem. Will reflowing one of the chip may fix the problem? If yes, which chip should I try reflowing?

The followings are some videos showing how it freezes.
https://www.youtube.com/watch?v=Sh-xR0Ijwck
https://www.youtube.com/watch?v=DqNiLzmBSIA
https://www.youtube.com/watch?v=g1FxQHt4Tgg

[lotas]

Re: Hisense 58H6550E - Freezes/Won't turn on

This one (eMMC).

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

use hairdryer to warm up the emmc.. warm to hot Temp will make him servent for you.. no freez... then log in service menu ( not normal user menu ) and from there look after "Clear Chip" this is hard reset. hope it will help.

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

Thanks for your suggestions and advice.

I have tried Diah's suggestion first using the hairdryer, but the tv still freezes after turning on.

Then I tried the reflowing using hot air station. I set the temperature to 375 degree celsius because in my past experience I need to set to this temperature in order to remove leds from the led strips. After that, when turning on, I only get the Hisense logo appears for a few seconds as in the video https://www.youtube.com/shorts/xohI-g_V-vM. Did I set the temperature too high and damaged the chip? Or should I try higher temperature?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

you caused BGA issue on emmc. try again with yours heat gun.. but you need to load heavy weight on emmc to keep it much it can stick at boards during the heat process,

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

you caused BGA issue on emmc. try again with yours heat gun.. but you need to load heavy weight on emmc to keep it much it can stick at boards during the heat process,

I did the reflowing by blowing hot air from the top. You suggest to load some weight on the emmc. Then I think I should blow the hot air from the bottom side of the pcb (there is no components on the bottom side). What temperature do you suggest I should use? Will the heavy weight on the emmc absorb some of the heat and so temperature setting should be higher?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

we dont know which kind of gun you are using... if its not for BGA rework. mean the hot air will be blowing with high pressure. and this matter caused shaking at the chip doesn't mater from top or from downside. thought the chip bed points distances between each less than 1/2mm . place weight will keep it in place however the air pressure high.
250-280° will be fine.

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

we dont know which kind of gun you are using... if its not for BGA rework. mean the hot air will be blowing with high pressure. and this matter caused shaking at the chip doesn't mater from top or from downside. thought the chip bed points distances between each less than 1/2mm . place weight will keep it in place however the air pressure high.
250-280° will be fine.

My heat gun is as shown on the photo. Is it suitable for BGA rework?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

yes.. this is BGA gun

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

As per Diah's suggestion, I should add heavy weight load to the chip while reflowing. Since it is so small, I could only think of pressing the chip with tweeters at the end of the reflowing. I tried several times (maximum temperature setting was 375°C but the results were just the same (Hisense logo appears for a few seconds). I found that the chip could not be moved at 375°C, so I thought may be the temperature was not high enough. I raised the temperature setting to 425°C and tried a few more times, but the results were the same. At 425°C, the chip could be moved and so I took the chip out hoping that cleaning the chip the pcb might help.

After removing the old solder, cleaning and adding new solder, I put it back. But the results were even worst, the tv could not be turn on (no Hisense logo, the standby light keeps red). Does this mean the chip has been damaged? Or putting back the chip must do "reballing" using solder balls and stencils as in some Youtube videos?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

you did answered your question self.. if chips removed.. should only work---->
(("reballing" using solder balls and stencils))

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

you did answered your question self.. if chips removed.. should only work---->
(("reballing" using solder balls and stencils))

It seems that there are different sizes of solder balls and stencils. How can I know which size is for this chip?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

It seems that there are different sizes of solder balls and stencils. How can I know which size is for this chip?

by chip name / type you will find the right stencils include ball size

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

by chip name / type you will find the right stencils include ball size

From the codes on the chip, I can find the datasheet https://www.datasheets.com/en/part-d...0818#datasheet. But on the datasheet, I could not find the stencil size and ball size. Can you give me more hints on how to find the stencil size and ball size?

One more question. This chip was programmed by Hisense. But the one on the market is not programmed, therefore, I can buy one and replace the current one. Am I correct? Or if there is a way to program the chip? Or will Hisense sell this chip which is programmed?

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

use universal stensils . for example and buy also set of balls. you will need them at future... the chio are just 153 balls

first you rebll the original .. but if it die capacity reached 64Gb then nothing you can do only new one to put on... no need to program it.. CPU will boot TV and open USB port where you can flash firmware .. it will written on the new emmc.

[lotas]

Re: Hisense 58H6550E - Freezes/Won't turn on

With a clean (empty without firmware) eMMC - the TV will not even turn on!
And in vain you heated eMMC to such a temperature, now even data cannot be read from it, they are afraid of overheating, especially "hynix". Along the way, you will have to look for a new motherboard.

[Diah]

Re: Hisense 58H6550E - Freezes/Won't turn on

With a clean (empty without firmware) eMMC - the TV will not even turn on!
And in vain you heated eMMC to such a temperature, now even data cannot be read from it, they are afraid of overheating, especially "hynix". Along the way, you will have to look for a new motherboard.

Lotas... this is android system.. with MT CPU. this cpu ready to open USB Port with key compination to load Firmware complete. ( Bootloader / recovery/ System).. also there are MT windows software with Service port terminal can write firmware.... on xda the software at section rooting media teck Smart TV

[tmhobadcap]

Re: Hisense 58H6550E - Freezes/Won't turn on

use universal stensils . for example and buy also set of balls. you will need them at future... the chio are just 153 balls

first you rebll the original .. but if it die capacity reached 64Gb then nothing you can do only new one to put on... no need to program it.. CPU will boot TV and open USB port where you can flash firmware .. it will written on the new emmc.

Like this post (https://www.aliexpress.com/item/1005...8da8sYbgY&mp=1), they have different diameter for the balls. Which one should I choose?

[lotas]

Re: Hisense 58H6550E - Freezes/Won't turn on

0.25mm.
But solder paste is better.
https://www.youtube.com/watch?v=9Aw8fEBJ_8Y

[Davi.p]

Re: Hisense 58H6550E - Freezes/Won't turn on

Lotas, in your opinion Chinese market solder balls are low quality?