Procedure to install new A Main Board in Sony

[horn1991]

I've gone through quite a few posts and whatnot. Have decided to try and replace the A (Main) board on a Sony KDL-46S4100.

What I'd like to know... is there a correct "procedure" when installing a new main board? An order of some sort? Do you have to reassemble the TV all the way, or can you just plug in the board and try it out?

I've plugged in all the connectors and it powers up, but no picture, menu, nothing.

If I unplug CN303 with is BL-ON, the backlight comes on, and it cycles through a full screen of just Green, then Blue, then Red, and then a horizontal striped screen with 1/4 of the screen each color, plus a gray stripe at the bottom.

Anyone have any advice?

Thanks,

Dave

[tom66]

Re: Procedure to install new A Main Board in Sony

Do you have the service manual for your TV? It sounds like your TV is stuck in test mode. Was the main board completely identical to your old one?

[horn1991]

Re: Procedure to install new A Main Board in Sony

I have a training manual...not sure if it is the same.

I will check your link to service manuals. There is a description in the back of my manual under "service mode item descriptions"...this is sort of what my TV is doing

Aging Mode:
This item can be activate to alleviate any LCD image retention
issues. When turned ON the TV will continously cycle through display
red, green, blue, and white rasters.

Not sure how to turn this off, or change it.

thanks for your reply.

Dave

[horn1991]

Re: Procedure to install new A Main Board in Sony

just checked your link...no sony training manual

[Th3_uN1Qu3]

Re: Procedure to install new A Main Board in Sony

Plug in a signal input. A lot of "test mode" symptoms are fixed with a signal input going to the set. Otherwise, a cable could be loose, or the EEPROM on the main board could be corrupted, or not identical to your original one. Try swapping them around.

[horn1991]

Re: Procedure to install new A Main Board in Sony

I don't know...I just can't figure out why it goes into "test Mode" when I DISCONNECT CN 303.

Not sure what an EEPROM is, so I don't know that I could switch it out.

Plugged in OTA and an HDMI input...no luck

[tom66]

Re: Procedure to install new A Main Board in Sony

Did a little poking around, do you have this manual yet?

Try page 21.

http://www.tgohome.com/ServiceManual...&Search=Submit

[horn1991]

Re: Procedure to install new A Main Board in Sony

Thanks for the manual link.

That reset procedure did not work for me.

[horn1991]

Re: Procedure to install new A Main Board in Sony

Let me pose this question...

The training manual tells me that there should be 12V on pin 13, and 3.3V on pin 7. When I use my multimeter to measure these voltages, I get 11.68 or something...same with the other.

Should I read EXACTLY 12V and 3.3V? Or just in the neighborhood? Don't know if my meter is just off a little, or maybe the Power board is not functioning properly?

Thanks.

[tom66]

Re: Procedure to install new A Main Board in Sony

I would say approximately. For the 12V it should be within 5% (11.4 to 12.6V) and the 3.3V would be 3% or 5%.

And, I know many Sony TVs are not happy with different main boards. Was the main board replacement exactly to-the-digit the same as your old one?

[horn1991]

Re: Procedure to install new A Main Board in Sony

old one: SO40FHD 07452-3, 48.71H01.031, 5571H01411G8370806BJ03F

new one : SO40FHD 07452-3, 48.71H01.031, 5571H01411G82204124J03C

not sure how exactly to the digit it is supposed to be.

[tom66]

Re: Procedure to install new A Main Board in Sony

That's pretty close. I'm not sure but maybe your replacement is a dud too. They are pulls from TVs which have been dropped or broken. You can usually get a refund or exchange with the supplier. Other than that, I'm lost.

[capkid]

Re: Procedure to install new A Main Board in Sony

Has anyone found a solution to this issue? I also have the alternating green, red, blue screen issue with the main board I just installed.

[capkid]

Re: Procedure to install new A Main Board in Sony

Ok, I found these links online after searching for days:

http://rapidlibrary.com/files/sony-k...yfr9i89on.html



Anyone try this?

[capkid]

Re: Procedure to install new A Main Board in Sony

Ok, I took a chance and installed the firmware; I now have a picture The one issue I'm seeing is that the Bravia splash screen doesn't appear at startup, so I'm not sure if there's a setting that needs to be changed. No biggie, I guess.

[tom66]

Re: Procedure to install new A Main Board in Sony

Don't fix what's not broken. I've always found splash screens annoying... why are you busy showing the splash screen when I could be watching TV now?? I appreciate some TVs use that time to decompress/load the firmware, but I'd say that's a minority.

[capkid]

Re: Procedure to install new A Main Board in Sony

Don't fix what's not broken. I've always found splash screens annoying... why are you busy showing the splash screen when I could be watching TV now?? I appreciate some TVs use that time to decompress/load the firmware, but I'd say that's a minority.

Yeah, I decided not to make any "improvements" and just go with it as-is; it's just the perfectionist in me that would want to make a tweak. It's working great right now.

[truep]

Re: Procedure to install new A Main Board in Sony

hey, Im in flower mound too! Sony's are very fussy with tcons and main boards. You need to get an exact replacement. Use the number on the bar-code sticker.

[capkid]

Re: Procedure to install new A Main Board in Sony

hey, Im in flower mound too! Sony's are very fussy with tcons and main boards. You need to get an exact replacement. Use the number on the bar-code sticker.

I found out that some Sony main board versions are interchangeable; it depends on the serial number and sometimes the panel version. There are two available substitutes for my model and serial number. I couldn't find the original anywhere at a reasonable price, so I installed one of the substitutes. So far, all the inputs are working fine.

[capkid]

Re: Procedure to install new A Main Board in Sony

I'm installing the back cover on the Sony. The previous owner only had four screws installed when I picked up the TV, and he had the rest of the screws in a plastic bag. Does anyone know where the flat washers and flat brackets in the last pic attach? I was thinking they might be part of the wall mount support, but I'm not sure. The service manual doesn't appear to mention them.