hi guys, just joined beoworld, impressed with the level of tech knowledge, shame i dont have it , anyway i hope you can help me

i have just aquired a b&o AV9000 which turns on but after a few seconds just cuts off ,sometimes it stays non long enough for a picture to appear ,then goes off ,any ideas please

nick1

The AV9000 uses the same mainboard like the MX6000/MX7000. And the problems are quite the same... some capacitors and broken solders around the blue plastic caps.

http://forum.beoworld.org/forums/p/24571/191760.aspx#191760

hi again die bogener, i have had the main board out and inspected the whole board with a magnifying glass, it all looks in pretty good order there are no dry joints ,no signs of burning and no signs of electrolite marks around the caps, i am wondering if this tv has had a new main board in the past few years, anyway if i turn on the tv when cold the picture and sound is fine for about 25 seconds then it switches off , if i turn it on straight away it comes on for about 10 seconds then goes off ,again and again it stays on for less each time , so my question is is there one part that is overheating and cutting out or is it a combination of things, one other thing, when cold the led on the infared sensor turns green almost imediately but takes longer to turn green when warmed up, any other thoughts from yourself or anyone else would be much appreciated

nick

The MX monitors all power supplies. If the voltage of one path is not high enough or to high, it will switch off.

Try the self test and the last error code, it will tell you if it was a power fail. "Menu 0 0 play"

A cold cap will work better than a hot cap. So the time will become shorter and shorter. There is no real hot spot in a cap, it's capacity is gone after a certain time.

A cap with acid around is dead and the worst possible defect.

Replace them all, they are all 20 years old. Caps have all a problem with time, even unused they will fail after a certain time. Even a brand new mainboard out of the storage will fail after 20 years...