Sony KDL-55HX701

[deer]

I am working on a Sony KDL-55HX701 LCD TV
The TV is displaying a 7 flash fault code.
The primary Power supply is DPS-74
The secondary power supply is APS-256

The standby voltage as marked on the secondary supply is supposed to be 3.3 volt and it tests as 6.4 volts with a meter.

I am assuming that is the reason for the fault code.

As I am a senior on limited finances I would like to attempt repairing rather then replacing the boards.

Any advise or direction would be much appreciated.

Thank You

[budm]

Re: Sony KDL-55HX701

Are you 100% sure that your meter battery is not LOW? Try testing some AA or AAA Voltage with your meter to see what it will show the Voltage as first.
How about the pictures of the whole backside of the TV showing all the boards?
'The primary Power supply is DPS-74' That is not valid part number.

[Diah]

Re: Sony KDL-55HX701

3 blinks over voltage protection (OVP), unit goes to the standby mode then displays the 3 blink fault. This is also a problem in the power supply circuit, check T603 and R672.

[deer]

Re: Sony KDL-55HX701

I checked the meter on a AAA battery and it showed 1.5 V so I assume it is working OK.
7 pics attached

Thank You for responding.

[deer]

Re: Sony KDL-55HX701

3 more pics

[deer]

Re: Sony KDL-55HX701

I accidentally had the meter on AC. I do have 3.3 volts DC on the standby terminals.
I do not know what else to check.
Any help is appreciated.
Thanks

[budm]

Re: Sony KDL-55HX701

Can you please verify for sure that you have 7-blink code?
7-Blink is for Thermal error.

Sony KDL-55HX701 CHASSIS AZ1-L service manual.

[deer]

Re: Sony KDL-55HX701

Thanks for the service manual.
Yes for sure it is a 7 blink code.
7 flashes a pause 7 flashes a pause and so on.
The TV started working again last night.
It is not like it started working after it cooled down as it took many days before it would work again.
I imagine this will happen again so would like to figure out why.
Any ideas?

[budm]

Re: Sony KDL-55HX701

Just look at the service manual to find out where the sensor is.
BTW, you do have the tools and experience to do surface mounted component replace/repair, correct?
Otherwise it will be moot point to troubleshoot down to component level since you are on limited finance.

[nomoresonys]

Re: Sony KDL-55HX701

https://www.ebay.com/itm/Sony-A17495...kz-U:rk:1:pf:0 Mainboard there, not sure if they ship to Canada.

[nicholas1110]

Re: Sony KDL-55HX701

Hi,

On some Sony models, 7 blinks can be the HLR board. It has definitely thrown me off before. Use the search function of the forum and search for Sony hlr to find more info.

[budm]

Re: Sony KDL-55HX701

This is the link about HLR: https://www.badcaps.net/forum/showthread.php?t=46810
https://www.badcaps.net/forum/showth...ard#post706697
nicholas1110, thank you for reminding us about the HLR board.

[yohnsee]

Re: Sony KDL-55HX701

Hello,
I might be over-suspicious, but the 6.x volts AC on the 3.3V DC standby line should not be there. I am thinking of the capacitors being worn out. You can test this theory next time the tv acts up. Grab a hairdryer, and heat up a little bit the output capacitors on the power supply. If I'm right, it will switch on.

[budm]

Re: Sony KDL-55HX701

Hello,
I might be over-suspicious, but the 6.x volts AC on the 3.3V DC standby line should not be there. I am thinking of the capacitors being worn out. You can test this theory next time the tv acts up. Grab a hairdryer, and heat up a little bit the output capacitors on the power supply. If I'm right, it will switch on.

He had the meter set to AC, see post #6, the standby Voltage is 3.3V not over 6V per meter setup error. Using meter in AC mode to measure DC will give bad reading especially the cheap meter with simple half wave rectifier on the input.

[yohnsee]

Re: Sony KDL-55HX701

Budm,
Ok, I was not aware of the meter he uses. I use mine in AC mode to measure the "waviness" of the supply line. If in doubt, I always hook it up to oscilloscope and give it a decent load.

[nomoresonys]

Re: Sony KDL-55HX701

I was glad to find this thread regarding the 7 blinking lights on the Sony KDL-55EX711. I have the same problem. My TV would go into the 7 blinking lights mode quite reliably after 1-5 hours of operation. I did the experiment to remove the HLR board. The TV stayed on overnight without an error. I examined the HLR board and did not find the capacitors on the I2C lines, SDA or SCL. I only saw the serial resistors.

I researched into the need for the RGB ambient light sensor. It appears to be a way to automatically adjust the backlighting for various lighting conditions in order to save power. I believe this feature can be turned off and the backlighting can be set manually and remains that way forever.

The fix that I implemented was to cut the wires (11,12) on the connector to the HLR board. This allows the remote control and LEDs to continue working on the HLR board.

Why does the temp error happen? The temp sensor is on the BAL (Main) board. The I2C bus runs to this temp sensor and the RGB ambient light sensor on the HLR card. Occasionally the temp data readings are corrupted by having these 2 devices in parallel on the bus. The corrupt readings are interpreted as the TV getting too hot and the TV shuts down and the LED flashes 7 times. Removing the RGB sensor from the I2C bus improves the data readings and no more errors occur.

I thought about buying a new HLR board on the internet but it seems the problem might come back, so I will live without the ambient light sensor and auto adjustments.

I like this solution, don't care for the auto adjustments anyway.