Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

[386]

Hi, I'm just wondering if anybody might be able to help me diagnose an issue with my Bravia KDL-40D3100.

When the power button is pressed, you can hear the sound of (what I assume to be) a relay click, but the screen never lights up, and the standby light just blinks red 8 times. What does error code imply?

How can I further diagnose the issue? Is there a certain board I can simply replace?

Also, I'm competent with a soldering iron, and have a multimeter.

Thanks very kindly for any assistance,

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

I've located the service manual, and the error appears to be in relation to the audio circuit.

I've checked all the internal connections, and everything looks pretty clean in there. Still no luck. There's no obviously burnt out components that I can locate. I'm assuming the fault is probably on the BG1 board, as it appears to contain all the audio circuit. Any suggestions as to where I could buy a spare BG1 board from? Kind regards

Any other ideas?

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

If you unplug the BG1 board, does it power up?

How about a picture of this BG1 board?

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

I took some photos of the BG1 board:

https://dl.dropbox.com/u/51809914/IMG_3742.jpg
https://dl.dropbox.com/u/51809914/IMG_3746.jpg

If you'd like other photos, or better photos of particular areas, just let me know.

Also, I've tested both speakers, and both are working correctly.

Oh, and here is the service manual: http://www.mediafire.com/view/?0jn6t0qt00p6n0k

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

There are several fuses, e.g. F4005 that are marked on the board. Can you test these?

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

I just tested them all, and they all seem fine, both sides of the PCB.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

How did you test them? (Just to be sure.)

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

With a multimeter.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

With a multimeter.

On ohms range?

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Yeah, none of them showed any signs of notable resistance.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

You mean the resistance was very low? OK, that means they are good.

The problem is likely in the audio circuit as you get the 8 blinks indicating audio problem. It could indicate a problem elsewhere.

I'm trying to browse the service manual but having difficulty getting a downloaded copy (MediaFire's viewer is crap; and when downloading it complains of a suspended account?!) The detection circuit for 8 blinks is on page 29 but when I try and zoom in it just changes page. Using Firefox.

Could you send me a PM so I can send you my email address, then you can email me the manual. I can then upload it on http://www.tgohome.com/ServiceManuals/.

Looking at the ckt, it looks like it only does overvoltage detection for 13V; if the zener for the protect ckt is short, it will always signal an OVP event. (Hence 8 blinks.) But I can't clearly see if there are other protections or the part # on the zener to reference it with the board and a replacement.

Did problem occur suddenly, or slowly get worse?

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

I didn't upload the manual, and I too had some frustration using the mediafire viewer. I'll let you know if I manage to get the original PDF. It's possible to right click the pages and print them to PDF, but it means doing each page one by one.

I can take some closer photos of various sections of the board if it will help locate the diode(s)?

Unfortunately, I am unsure of how the problem developed, I received the TV in it's current state.

Thanks for all your help.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

That's fine. I get a lot of TVs to repair without knowing what the previous problem is.

Can you "print to PDF" page 29 as PDF and upload it here?

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Yeah sure, here it is:

Edit: Just realised I could upload to the forum directly.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Okay, it looks like all the protection does is sense over-voltage, DC voltage on the speakers, and watches for the FAULT signal from the amplifier IC. Page 37 has a board layout with part numbers on it. I can't seem to find this print to PDF option so can you upload this too.

It could be:
- Shorted amplifier driving speakers to DC
- FAULT signal from amplifier IC
- Over-voltage protect
- Failure of any of these detections

What you can try and do is locate R2204 (100k chip resistor), lift one leg of it, and see if TV powers up. Disconnect the speakers to prevent DC damage, if there is any. (You can check later with a meter to see if the speaker outputs have DC on them.)

If it then powers up, you can either replace the BG1 board (pricey option), or you can try and locate the fault. My bet would be either the OVP zener is short, or the amplifier chip is shorted to DC. (Possibly both were damaged by over-voltage, for example a surge...)

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Pages 37 and 38:

[386]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

R2204 is on page 38, in the bottom right-hand corner. I'm not sure I'll be able to solder something that small though.

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

I'm having no luck seeing R2204!

[tom66]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Oh, I see it.

Very tiny. It will be tricky but to remove an SMD component (it is probably too small to lift just one leg) blob a bit of solder over it. Then it will come off easy with the blob.

If the TV then powers up, then the fault is being suppressed temporarily.

You probably won't be able to easily reattach it, so you would need to order a reel of 100 or so of them, for about £1.

[randtek]

Re: Sony Bravia KDL-40D3100 - Doesn't Turn On - Standby Light Blinks 8 Times

Have you tried unplugging the speaker connector? I have seen problems like this caused by a piinched speaker wire.