Sony A1e 5-blinks help

[jchon]

Hi I'm new to trying to repair TVs, but I saw a broken OLED offered for a reasonable price and thought I'd try my hand at it.

I found the service manual, which was critical to know where to probe.
https://www.manualslib.com/manual/20...1e-Series.html

With it I was able to determine that my DKA board was bad, when P_ON#1/2 gets enabled REG_12 on the DKA board collapses. I'm assuming one of the downstream regulators has a short, but I couldn't work out which rail/component and replaced the DKA board entirely.

Unfortunately the 5-blinks still persists.

I've gone through all the troubleshooting flow charts (even for fault codes that I don't have) and measured all the components that are called out and the rails. On the BKA board that's 1.5V, 1.05V, 3.3V, 5V, 1.8V and on the DKA board 3.3V, 1.5V, 1.1V & 1.0V. The TCON board only takes in TCON_12V & TCON_24V but neither of these rails are up because the DKA is not asserting TCON_12_ON or TCON_24_ON. I also ohm'd through all the fuses.

The only step in the 5x blinks troubleshooting flow is to measure TCON_12_ON and if it's not asserting replace the DKA, which I've already done.

In the Troubleshooting Triage table it says that the TCON board is the most likely culprit for 5x blinks, so I also replaced that. Still no luck.

I've visually checked the harness wiring and flex cables under a microscope and didn't see any obvious faults. I ohm'd through some of wiring I thought might be critical such as the I2C lines between the DKA & BKA.

Does anyone have any suggestions I'm overlooking?
Any ideas why the DKA board isn't asserting TCON_12_ON and TCON_24_ON?
I verified that the power supply will generate those voltages if the DKA asserts those lines. Is it a good idea or bad idea to try to jumper from 3.3V standby to TCON_12_ON?

Does anyone know the function of AC_DET_IN on the DKA? This measures as 3.0V and routes to AC_OFF_DET on the power supply board. But I couldn't work out which board is supposed to be generating this signal and what its expected state is.

I'd appreciate any help! Thanks!

[William1967]

Re: Sony A1e 5-blinks help

Many of the error messages for this model are EMMC related. If the software is damaged because the EMMC has reached the "end of life" status, the device will not start up and you may get strange errors or the device will start for a short time with the Sony logo, sometimes the Android logo and then sometimes go off with an error message, sometimes not.

[leszekp]

Re: Sony A1e 5-blinks help

Older Sony chassis has error 8 , when software corrupt .Which is panel manufacturer ?

[jchon]

Re: Sony A1e 5-blinks help

Thanks William & leszekp.
This Sony has an LG OLED panel.

The OLED panel doesn't turn on at all before the status LED displays the blink error pattern.
The panel's TCON_12V/24V power never gets enabled, so the error condition is happening fairly early on.

Based on the 5-blinks code I believe this means that the main processor can't talk to the T-Con board.

I've replaced every board except the main one.
So I suppose it's possible that I'm hitting an eMMC corruption.

I just wish there was some finer grain debugging steps to diagnose the exact issue.
Replacing the main board is pretty pricey without knowing for certain it will fix the issue.

Does anyone know if it's possible to remove and re-solder a blank eMMC and re-flash it via USB? Or is using a pre-programmed eMMC the only option?

Do TV's typically have a UART port somewhere that prints out boot logs?

Thanks!

[leszekp]

Re: Sony A1e 5-blinks help

You need pre-programmed eMMC , I think , just like in older Sony chassis .