Hello

Can anybody help with this problem?  Without any warning our much loved and carefully polished LX6000 has decided to stay in standby and no amount of button pressing on the remote will switch it on.  The standby LED goes from red to green for a short time and then goes back to red each time the remote button is pressed.

Thanks to Beoworld I have the service manual and with guidance could attempt a DIY repair if it's possible.

What you have here is one of the more difficult problems to fault find even for the most experienced engineer, because something in the TV is overloading the power supply or one of the power lines is going overvoltage and the "crowbar" circuit is being triggered.

If you have a good multi-meter and have electronics knowledge, then I can walk you through some of the key steps, however if you do not have the basic tools and knowledge, then you are unlikely to be able to do a DIY repair unless you are very lucky.

If you go to section 7-4 of the service manual and you feel able to follow their instructions for switch mode power supply issues the I can take you through all the other tests. If you cannot, then I feel this will have to be repaired by your B&O engineer.

(moderator, maybe this should be moved to the workbench ??)

Assuming you know a bit about servicing tv's / electronics:

start with measuring the HT transistor if it's short circuit and while you're there check the C connected to the collector of this transistor, i believe it's called C102 (6n8): a common fault is that the solderings of these get lose.

check if the stand-by power (8 volt) is ok.

chech with ohm meter (tv unplugged!) the loads on the output of the power supply (so the +15, +8, +135 etc) to see if there's any unusual low load.

check for bad solderings in the power supply area (especially the part of the PCB from the BUT11 in the power supply in dthe direction of the HT transformer, about 2-3 inches away from the BUT11), you may need a magnifying glass...

Whilst you can do all the checks mentioned, I think it is important to determine if you are willing and able (i.e. knowledge of electronics/servicing and have the tools like multi-meter and best of all scope etc) to do this fault finding.

Assuming you are able and have the tools, then the first thing to determine is:-

1. Is the TV going back into standby because of a power related fault or a micro processor fault, either will cause the TV to go back into Standby, but it has to be said that it is more likely to be power related.
2. This can be best done by putting the TV into Service Mode as per the Service manual you already have.
3. When you put the TV into service mode it stops it going back into standby after switch on BUT if you have a short circuit component which is the fault it can cause further damage

If you do not have the tools etc, then its your B&O engineer or someone on the Beoworld site with the knowledge and lives near to you.