Beovision LX5000 going into standby - UK Vintage Radio Repair and Restoration Discussion Forum

stubbyeddy · 21st Apr 2019, 7:38 pm

Had this B&O set a while and never got to the cause of the problem. The TV works perfectly fine but has a fault where after a few minutes the set just goes into stand-by, then you can power it up again and after a few mins the same happens. I have re flowed all the joints on the circuit boards and replaced most of the old electrolytic capacitors hoping that might cure the problem, but still the same issue... any ideas anyone. The baffling thing is the sound and picture are perfect for the short time it working between powering it up!

Eddy

PWH · 22nd Apr 2019, 7:51 am

Just a thought, is there a sticky remote button? View with a phone camera to see if the LED is on.

Max Ripple · 26th Apr 2019, 11:58 am

Yes indeed,the remote control button pad is a plastic sheet with conductive paint "blister's" for each function.The conductive paint can break up and cause spurious commands to be sent to the tv.The power down button being the most used of course!
Try taking the batteries out while viewing and see if the set remains on?
Otherwise,you may have an intermittent problem within the set that is triggering the sophisticated integral"powerfail" system employed in these tv's.
There is a service mode whereby you can check the powerfail memory to see if a particular component or section of the set is failing?

Super telly,well worth sorting.

ekcopyephilips · 26th Apr 2019, 12:36 pm

When i worked at Sanyo years ago they produced a chassis called an EH1 which was a 4:3 100Hz set for the German market.

Long story short, but, in certain 'picture' modes some sets would shut down and go into protect mode. It turned out to be a current sensing thing, i think it was found out that it was down to the 'Q' value of the DY winding on some tubes being too high, or it could have been a coil on the board. I cant remember what as it was over 20 years ago now.

So if not remote, look at the picture mode the set is in, see if it still happens in other picture modes and look at any current sensing areas.

AJSmith625 · 26th Apr 2019, 8:22 pm

Another test worth trying is disconnecting the infra red remote receiver diode in the set, as any random 'noise' produced here could be interpreted as a go to standby command. This was a common fault on a Curry's branded set, one of the last sets made by GEC with a PIL tube. Can't remember the chassis number as it was over 30 years ago.

Alan.

stubbyeddy · 28th Apr 2019, 10:52 pm

Thanks for your help and suggestions, I had a good look at the boards in the set and I could see a few obvious electrolytic capacitor fails on a few of the boards where the electrolytic had leaked on the boards so after cleaning them and changing them it resolved the issue... but now I have another issue no sound. There is very very faint sound listening via headphones but only slight occasional loud popping from the main speakers... no idea where to start.. the whole chassis is brittle and breaking apart..

John123 · 29th Apr 2019, 3:08 am

Most likely dry joints, although there could also be lifted/ damaged PCB print depending on how bad it is. Try re-soldering/ touching-up around the audio output IC(s), and also around the headphone socket itself. Continuity test any suspect traces.

If you come across any gold-coloured electrolytics (ROE? Frako? - can't remember off the top of me 'ead!), change them as they have a tendency to short..or at least check with an ESR meter if you have access to one. Also check the mains input side for any RIFA smoke bombs!

It might just be quicker to change them all as they'll simply be too old to be any good.

21st Apr 2019, 7:38 pm	#1
stubbyeddy Pentode Join Date: May 2005 Location: Newtown, Mid Wales, UK. Posts: 186	Beovision LX5000 going into standby Had this B&O set a while and never got to the cause of the problem. The TV works perfectly fine but has a fault where after a few minutes the set just goes into stand-by, then you can power it up again and after a few mins the same happens. I have re flowed all the joints on the circuit boards and replaced most of the old electrolytic capacitors hoping that might cure the problem, but still the same issue... any ideas anyone. The baffling thing is the sound and picture are perfect for the short time it working between powering it up! Eddy

22nd Apr 2019, 7:51 am	#2
PWH Heptode Join Date: Mar 2003 Location: Waiheke Island, New Zealand Posts: 503	Re: Beovision LX5000 going into standby Just a thought, is there a sticky remote button? View with a phone camera to see if the LED is on.

26th Apr 2019, 11:58 am	#3
Max Ripple Pentode Join Date: Oct 2016 Location: Near Coventry, West Midlands, UK. Posts: 186	Re: Beovision LX5000 going into standby Yes indeed,the remote control button pad is a plastic sheet with conductive paint "blister's" for each function.The conductive paint can break up and cause spurious commands to be sent to the tv.The power down button being the most used of course! Try taking the batteries out while viewing and see if the set remains on? Otherwise,you may have an intermittent problem within the set that is triggering the sophisticated integral"powerfail" system employed in these tv's. There is a service mode whereby you can check the powerfail memory to see if a particular component or section of the set is failing? Super telly,well worth sorting.

26th Apr 2019, 12:36 pm	#4
ekcopyephilips Hexode Join Date: Dec 2006 Location: Norwich, Norfolk, UK. Posts: 440	Re: Beovision LX5000 going into standby When i worked at Sanyo years ago they produced a chassis called an EH1 which was a 4:3 100Hz set for the German market. Long story short, but, in certain 'picture' modes some sets would shut down and go into protect mode. It turned out to be a current sensing thing, i think it was found out that it was down to the 'Q' value of the DY winding on some tubes being too high, or it could have been a coil on the board. I cant remember what as it was over 20 years ago now. So if not remote, look at the picture mode the set is in, see if it still happens in other picture modes and look at any current sensing areas.

26th Apr 2019, 8:22 pm	#5
AJSmith625 Pentode Join Date: Nov 2017 Location: Birmingham, West Midlands, UK. Posts: 171	Re: Beovision LX5000 going into standby Another test worth trying is disconnecting the infra red remote receiver diode in the set, as any random 'noise' produced here could be interpreted as a go to standby command. This was a common fault on a Curry's branded set, one of the last sets made by GEC with a PIL tube. Can't remember the chassis number as it was over 30 years ago. Alan.

28th Apr 2019, 10:52 pm	#6
stubbyeddy Pentode Join Date: May 2005 Location: Newtown, Mid Wales, UK. Posts: 186	Re: Beovision LX5000 going into standby Thanks for your help and suggestions, I had a good look at the boards in the set and I could see a few obvious electrolytic capacitor fails on a few of the boards where the electrolytic had leaked on the boards so after cleaning them and changing them it resolved the issue... but now I have another issue no sound. There is very very faint sound listening via headphones but only slight occasional loud popping from the main speakers... no idea where to start.. the whole chassis is brittle and breaking apart..

29th Apr 2019, 3:08 am	#7
John123 Heptode Join Date: Jan 2007 Location: Luton, Bedfordshire, UK. Posts: 891	Re: Beovision LX5000 going into standby Most likely dry joints, although there could also be lifted/ damaged PCB print depending on how bad it is. Try re-soldering/ touching-up around the audio output IC(s), and also around the headphone socket itself. Continuity test any suspect traces. If you come across any gold-coloured electrolytics (ROE? Frako? - can't remember off the top of me 'ead!), change them as they have a tendency to short..or at least check with an ESR meter if you have access to one. Also check the mains input side for any RIFA smoke bombs! It might just be quicker to change them all as they'll simply be too old to be any good. __________________ Regards, John Last edited by John123; 29th Apr 2019 at 3:14 am.