Hello anybody

Any idears about this fault, i have recently installed a brang new origional B&O power supply pcb4 into my beovision 3/32 i am sure the connections are all made correctly but i still have a red glow and only that and considerably lighter on the pocket! is there any thing i am missing funndamentally in the set up "bearing in mind that i cannot get the thing to even power up the degausing or anything, its the snag where you try to switch on but get a green light only! still the fault so i am thinking now it has to be on the deflection pcb 5 i have the following volts on P43pin6 140+volts in a burst then it decays to 18V.  & 15V on P43 pin 1 these being measured on the flex lead direct from pcb4, HOWEVER when reconnected to the deflection pcb 5 i get a variable voltage ranging fron 30-70V+. i have traced  the track to the flyback trans @ pin 3 on the horse shoe  which should be 141V according to the flyback data sheet. As far as i can gather this 141V is a sort of surge voltage to kick the flyback into life so it then supplies various voltages throughout.  C1 on the deflection pcb 5 tooks MARGINALLY  swolen on the base but i am a loss as what could be the fault now.

Any help would be very gratefully appreachiated...

Maurice

Remove the board from the neck of the tube and then see if it switches on.  If it does (you will get sound) then you probably have an internal short in the tube.

You can check for this with a meter.  With the board removed you should have infinite resistance between all combinations of pins except 9-10 which is the heater.  The usual is a short between either 5 (g1) or 7 (g2)and 6 (g), 8(r) or 11(b).

If you find a short you can try burning it away by discharging a capacitor between the offending pins or using the mains with a 40W bulb to limit the current.  It may last or it may come back and only a new tube will really solve it if it is this...

Richard

Hi Richard

ive just tried your suggestion and it fired up "the degausing etc energised" how long do i have to wait before i test the pins as you suggest, trouble is its been such a beautiful picture on this set

Regards Maurice

Just power down, remove the mains plug and you should be ok to test straight away.  I brought a set with a fault like this complete with a surround module and STB controller and the set lasted 6 months.  I have kept the chassis & speakers and had already moved the modules to one of the other BV3/32s I have.

Richard

Hi Richard

lmao! i used to do this sort of stuff with lancia beta coup'es but it was on a more mechanical dimension, i will get back to you with the results asap. Thanks so much for your help with this. Ok i have measured the pins there is continuity between pins 9&10 the heater and also pins 5 & 12.

"""OK A QUICK UPDATE ON THIS""" after some tapping with the hand of a paint brush its now fired up and running!!!

Maurice.

Congratulations   Sorry for the reply, i've been to a party

You must be mistaken with pin 12.  If you look at the wiring diagram in the service manual then nothing goes to pin 12.  Are you counting the in the right direction?

The only doc I can find has the following: -

1 DYNFOC

2 STATFOC

5 G1

6 Green cathode

7 G2

8 Red cathode

9 Heater

10 Heater

11 Blue cathode

15 AQUADAG

16 EHT

From what I remember 1 & 2 are separate and then there is a gap for 3 & 4

Anyway, be prepared for it to stop again and again

Richard