New to this – Beovision 7802

[ANDREW PARKINSON]

Hi all, I picked up a Beovision 7802 at a local flea market a couple of years ago. I had a great couple of years using it with my old Acorn Electron and Spectrum 128k+ when in January – poof! White smoke came from the back of the telly and though the picture was still on I quickly unplugged it. I’ve owned enough retro tech to recognise the smell of a burned out capacitor! I don’t have much hands on tech experience – I think the smoke came from the right of the telly as you look at it ( so on the rear thats the left side). I can’t find any drawings or schematics for this particular model. I’d hate to see this end up in a landfill, is it a simple enough repair (if it’s just replacing a capacitor I’m fine with that) or is this model basically junk? I haven’t seen any of these for sale online so I guess that either makes the worthless or rare! Any help and advice would be appreciated. Thanks

[lausvi]

I quite like the orange highlight color they used on the button labels on these models!

There is a service manual of the related 7700-8800 series: https://elektrotanya.com/beovision_7700-8800.pdf/download.html

If you look at page 5 top-left: just after the mains input and power switch there is a fuse and 6C2: a 470nF filter capacitor across the mains. This might well be infamous Rifa mains filter cap, which is known to lose its sealing (the case forms cracks and air and moisture gets in) and it will eventually short itself, often with a bang. And as it’s straight across the mains, there is a lot of power for the fireworks.

If this is the case, the blown cap should be easy to see. That would be on the module 6 (power supply) which is on the right (looking from the rear) side of the set. The smoke could have of course come from any side of the case, depending on the location of air grills. The cap is not strictly necessary (for the TV to work) but it’s used to reduce interference from and to the mains. If it’s replaced, it MUST be an X2 type safety cap (commonly available) designed to live across the live mains.

Remember to be careful when working on a CRT TV! If it has been unplugged since january, it should be safe enough by now 😀

Location: Helsinki - Finland

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[ANDREW PARKINSON]

Wow thank you for such detailed information and the link to the service manual. I will have a look at that this weekend and see if it looks like it is the Rifa cap and order a modern replacement.

 

And I’m well aware of the dangers of working on CRTs, I’ve watched (from a distance) my friend repair many retro arcade cabinets!

 

Thanks again

[lausvi]

On another look, there’s actually another service manual, which includes the 7802: https://elektrotanya.com/bang_olufsen_beovision_5502_7802_8802_8902_9002.pdf/download.html

if the PCBs match, the suspect cap C2 (which in this manual is actually a 100nF, not 470nF) is here:

and it’s located in section D1, which appears to be here in your picture:

Location: Helsinki - Finland

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