Kunft 28DCG220014 TP.SIS231.P83 boot loop, SPI flash dump/firmware?

Hello,

I have a Kunft LED TV model 28DCG220014 (serial G919A4DF2EA163581) with the following issue: when I power it on, the logo appears, but after a few seconds it shuts down and restarts, getting stuck in a continuous boot loop.

I have searched several forums and found reports from other users with the same problem, where it is suggested that it may be related to SPI flash memory corruption.

However, I have not been able to find compatible firmware or clear instructions on how to reflash this TV.

I would like to know:

* If anyone has a dump/firmware for this model (or for mainboard TP.SIS231.P83 or equivalent)
* If it is possible to update via USB or only through an SPI programmer
* If anyone has already solved this issue and can share the procedure

Additionally, I would like to know if there are compatible mainboards available for purchase (new or used), and where I could find them.

Thank you in advance for your help.

AI: Could you share the exact LCD panel model (from the sticker on the panel) and any full code/revision printed on the mainboard, not just “TP.SIS231.P83”?
28DCG220014
AI: Have you already tried any recovery method (USB update, factory/service menu, or reading/writing the SPI chip), and if so, what is the exact SPI flash chip part number?
TP.SIS231.P83

according to serial number
model KUNFT 28DCG220014, main TP.SIS231.P83, panel M280X13-E3-H(G3)

here is the firmware

how to perform a usb recovery
copy the file SISEU23X8M.bin on an empty usb stick fat32 formatted
unplug the power cord
insert the usb stick in the tv and reconnect the power cord
look at the standby led, at the beginning it flashes slowly, after about 1 minute it doubles the speed, update completed
unplug the power cord and the usb stick
reconnect the power cord and turn on the tv: it will start in first installation mode

if it doesn't work with the usb recovery, you have to replace the spiflash U5 25Q64 and program a new one using the file SISEU23X8M.bin