Hey guys! Interesting thread!

I have a V1-40” where one channel suddenly was distorted on higher volume levels. It’s the left tweeter.

I took the unit apart and found the three speaker setup uses two custom icepower boards each with two 32W amps.

One board utilizes just one channel. The left board where the issue lies uses just channel “100” closer to the board edge on the output port side.

I was thinking about trying to switch it to use the other channel and thereby relieve the issue entirely (hoping that the other channel is free of issues).

However, I’m still curious to why this has occurred and started looking at the chips and layout. It seems to have much in common with the beolab4 boards and if so it might be worth looking closer at.

AFAIK it seems it uses almost the same circuit as B&O dis on the Beolab 4 pcb and I read here that they changed to another provider that might be better.

I’m including photos here of both sides to let you guys have a look and possible advice me on what I can and should do. Hope that’s okey🙂.

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Hi

i think...it's 85% the same as BL4 or BL4000NK2 board

try to check resistors closest to M3307 / 8pin chip and check 2 mostet transsitors in the same area.

If that is ok..check all resitors in the board.

 

 

marexy wrote:

Hi

i think...it's 85% the same as BL4 or BL4000NK2 board

try to check resistors closest to M3307 / 8pin chip and check 2 mostet transsitors in the same area.

If that is ok..check all resitors in the board.

Hello Marexy,

What do you mean with check them? I found that the PCB is called "35" or 8004783 anad that the Beovision 11 has the same boards. It seems to be an iteration on the BL4 and BL4000mk2 amps. 

I would like to try and change to use the other channel that probably isnt faulty. Do you think that could be possible and if so, which pins should I rearrange?
It seems FP1,2,10 and 11 on P1 is connected to the main logic board, as is the free cable connected to P3.

I managed to make it work! I measured all the pins and some other things to figure out what they do. Then I simply switched pin 1-11 and 2-10 on the input. And moved pin 1->3 and pin 2->4 on the output to make use of the input and output that was before unused.

It seems to work perfectly! I’ve been doing some tests and it all is fine and sounds lovely.

Why the other amp channel started distorting is something I will leave for now and I’ll re-assemble the tv again tomorrow after some more tests.

Thanks for the advices here too!

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Michael wrote:

I managed to make it work! I measured all the pins and some other things to figure out what they do. Then I simply switched pin 1-11 and 2-10 on the input. And moved pin 1->3 and pin 2->4 on the output to make use of the input and output that was before unused.

It seems to work perfectly! I’ve been doing some tests and it all is fine and sounds lovely.

Why the other amp channel started distorting is something I will leave for now and I’ll re-assemble the tv again tomorrow after some more tests.

Thanks for the advices here too!

Very nice outcome

Just to give an update on this issue.

I decided again to go the easy way and I had the board replaced as they are still available from B&O. Nevertheless, I bought replacement ICs from Digikey as spares as they are still available from them even if they are obsolete. If the amplifiers fails again in the future and are no longer available from B&O, then I will try to repair them.

The official part number is indeed STS9NF3LL and the chip is marked 9F3LL as the others before.

Marexy, if you have time, could you write a short step by step procedure explaining how to diagnose the problem on the board and upload it to the service manual section of the forum. I did the same a long time ago about capacitor replacement for the North American MX 5000.

Best regards,

Jean

 

 

Thanks a lot,

Jean

Hi all, coincidentially, i am also working on those now.

I kept defective in the past and have 5 now.

All had other defective components apart from some fets: resistors (the big and/or small 1K5 apart from the 10R) and even smd transistors on the opposite side of the fets.

Anyway, the challenge still is the fets.

With a bit of luck the replacement module is still available for around 60 euros (that used to be the price here) and i hope to see if the newer types use the FDS6294 fet as a direct replacement.

On a Dutch general repair forum there is also someone working on this, let's see what we can figure out....:)

 

 

If you decide to sell PCB's let me know :)