May 22, 2023, 5:53 AM
Post #1 of 1
I'm currently working on repairing a malfunctioning Sony TV model KD-65XE7005 with the mainboard 1-981-926-21. I would appreciate your assistance with this issue.
Sony TV model KD-65XE7005 - only Sony logo for 3 seconds
Upon powering on the TV, the Sony logo appears for approximately 3 seconds, after which the backlight remains lit, the screen remains black, and nothing else happens. The TV consumes around 55W initially and then drops to 35W. The indicator LED remains solid white. It doesn't respond to the remote control. When attempting to update the TV using a USB dongle, the dongle briefly flashes but nothing else happens.
Here's what I've tried so far:
When I received the TV, it wasn't functioning at all. Upon powering it on, the relay clicked twice, but nothing else happened. According to the service manual, there was a voltage issue behind the Wi-Fi inverter on the mainboard, indicating a faulty CPU (MT5597BMEJ). I found a similar issue described by another user on a forum (https://badcaps.net/forum/showthread.php?t=82203) who resolved it by replacing the mainboard.
I ordered a used one from England, but it didn't revive the TV, nor did it successfully load the update from the USB dongle.
All the voltages on the English mainboard were fine, so I tried swapping the memory modules (EMMC THGBMDG5D1LBAIL), but the TV's behavior remained the same as I described at the beginning (Sony logo for 3 seconds).
I then purchased another used mainboard from an ebay auction, and it exhibited the same behavior as the one from England. I tested the contents of all three EMMC modules on both used mainboards, and they all behaved in the same manner.
I couldn't find any relevant firmware DUMP files on Google. If anyone happens to have one, I would appreciate the opportunity to test it.
Thank you for your attention and any assistance you can provide.