[Guy]

Die_Bogener wrote:

You have cleaned the acid of the smd caps?

I actually cleaned the IR board before changing the caps, because the area (3-pins) where it connects to the main board looked discoloured. I have now given it a further clean and there is no change.

I have had to pack it all away now because 4-year-old grandson is staying this weekend, but I will have another play next week.

Thanks again for your suggestions.

[Guy]

Thanks Die Bogener – all useful info!

However …

IR control worked for a while, then worked intermittently, then stopped working ?

Touch control is still fine, and 5v still being supplied to IR board.

Not sure what to look at next!

 

[Guy]

Update:

Resistor R1 5.6 Ohm replaced (temporarily with ‘metal foil’ replacement for controlled testing, now aware of fire risk).  Correct T1.6AH fuse also fitted (incorrect one was fitted by previous owner).

Tested LC2 again:

• 5V now present including to IR board.
• IR still not working.
• Touch control is working – dimming/switching correctly with 60W bulb fitted.

Obvious place to look next was the 2 x 22uF capacitors on the IR board.

I replaced these with 22uF 16v Tantulum beads that were left over from my BL5000 two-way repair.  Easier to solder than SMD replacements!

Now fully working with both IR and touch control ?

So a couple of questions before I place order with RS for correct fireproof resistor:

• Any reason that I shouldn’t leave those tantalum bead caps in place?  I am happy to replace them in the future if the IR stops working again.
• Any suggestions for replacing the (missing) little contact rubber between the PCB and the dome foil?  I was thinking of cutting a small piece from the Beo4 screen connection ‘rubber’.  Any better ideas, or is the part still avail from B&O?

Thanks for everyone’s helpful comments so far!

[Guy]

lausvi wrote:

Ah, now I had a look at the schematics and indeed there were two 5.6 ohm resistors. I believe I had to remove the IR module to get access… My local dealer had one listed as a ‘flame proof resistor’, which appears to be a SPRX1/2 by Koa. The datasheet states: ‘fixed metal film, Flameproof, Ceramic Body, Flame Retardant Coating”. This was as good as I could get at the time.

Thanks for the update – very useful.

I did had a quick search and found this: https://www.partco.fi/en/electronic-components/passives/resistors/flame-proof-resistors/12325-fres-05w-5r6.html

… so I’ll either go for that or the TE Connectivity one that I linked to earlier.

[Guy]

Thanks Martin – I’ll be sure to fit the flameproof one.  To be honest, I wasn’t aware that resistors could be ‘flameproof’, but can see that in this application they are being used as a kind of secondary fuse, hence the safety requirement.  Every day’s a school-day!

I was aware that capacitors have to be carefully chosen in the PSU stage.  I had an issue with a Beocord (V6000) a few years back.  My wife watch watching a VHS tape downstairs when I heard screaming that the video was ‘on fire’.  Actually it just had lots of smoke coming from it (by design?) rather than fire, but you can see the damage here:

The smoke absolutely stank! The acrid smell hung around and was so bad that the Beocord went in the garden immediately and off to the dump the next day!

[Guy]

lausvi wrote:

I’ve had two cases of a dead LC2, and both times it was the 5.6ohm resistor (although my notes say R3?) that had gone open. No burn marks or anything. Both units work now.

Thanks for that Lausvi – sounds promising! R3 is also 5.6 Ohms but it’s on the top side of the board near that white bridging wire (hidden by the IR module in my first picture).

Did you find/fit a flameproof equivalent/replacement? The only one I can find is this:  https://uk.rs-online.com/web/p/through-hole-resistors/1870824

 

[Guy]

Die_Bogener wrote:

Metall oxide or wire resistors dont burn… coal resistors do burn.

Thanks Die_Bogener. I actually ordered metal film, so I will probably fit those for testing and then replace with the TE Connectivity Flameproof (which is metal oxide) if I am going to use it permanently.

EDIT: And I have now read Martin’s useful post and link here: https://archivedforum2.beoworld.org/forums/p/36289/305349.aspx#305349

[Guy]

Die_Bogener wrote:

There are 2 brown caps, the 220uf is prone to fail… yes, with shorts killing the resistor.

Thanks – I’ll look at those. Should be easier than changing caps on a BeoLink5000!

[Guy]

???

Yes it’s getting to be a pain!  So much of my stuff is in boxes since moving to a rental in Feb.  We just need UK house prices to crash (any day now …) and then I’ll be able to buy somewhere permanent to live!!

 

[Guy]

Dillen wrote:

Looks like a flame-proof type.

Thanks Martin – that explains the ‘safety critical’ annotation in the circuit diagram.

Also makes them hard to find!

[Guy]

matador wrote:

After thinking it twice, I thought that even if repaired, it would be a nonsense to have to use any 40w bulb nowadays and dropped the idea.

I can’t remember what bulb I used but I am pretty sure that I tried my other working LC2 with some type of energy (LED) bulb and it worked (in the on/off mode, which is all I want). I can’t check because it’s in a box somewhere, but I’ll let you know when I have fixed this one!

I use JBMedia’s Lightmanager Pro for day-to-day (night-to-night?) light control and that works very well.

Anyway, resistors (pack size 50!), fuses and Zener on order …

[Guy]

Thanks Die Bogener. I initially suspected those IR board caps (C7 and 8, both 22uF) after reading this old thread: https://archivedforum2.beoworld.org/forums/p/11884/103685.aspx#103685

The IR board isn’t even getting 5V, and that main board resistor (R1) has blown. Not sure whether failed caps (do they fail short?) would have caused this.

I am going to have to come back to this when I have dug out my soldering iron – it’s in a box somewhere …

 

 

[Guy]

matador wrote:

Please let me call them for you…

I see that Banbury Lodge has 22 rooms. I have enough Beocom landline phones to fit one in each, with several left over … ?

[Guy]

matador wrote:

https://www.addictionhelper.com/rehab-locations/oxfordshire/banbury/banbury-lodge/

Ha ha – that’s just down the road from my house ?

But I just need two suitable Beovisions and a slightly older VHS player than the two I already have, and then I’ll be able to connect it all up!

[Guy]

Here we go:

And instructions:

[Guy]

Tignum wrote:

An MCL junction box?

Close! The hole (and the two the other side) are for co-ax (aerial) cables.

[Guy]

matador wrote:

On the top view it’s a C7 power plug and there is only one “screw ear”, on the side views it’s a 12v jack and both “screw ear” are there.

I’d missed that – well spotted!

Great inputs – let’s find some other strange eBay B&O listings about which to ponder …

Here’s one I actually bought. I now know what it is, but any guesses?

[Guy]

YannChris wrote:

One of the pictures shows part Nr 1638, with is Beolink Active.

Yes I saw that on the casing, but I think the internals and end plates are bespoke for another function – or the modifier has done an excellent job of disguising the ML socket etc! The usual ‘raised’ socket labels and ‘BANG & OLUFSEN’ logo are also missing, and I have never seen such white lettering.

Sia43 wrote:

Could it be a low pass filter, extracting the Subwoofer frequencies from the rest, like the Powerlink outs on Beolab 2 or 11?

We’ll never know. Strange that the Subwoofer socket is an input rather than output? Perhaps it’s a dealer device like that speaker switch that has been discussed in the forum before.

[Guy]

matador wrote:

Quite a weird thing indeed, but I’l not a specialist…

Guy wrote:

And more importantly, do I need one?

Yes you do, to tell us what it is….

Ha ha ? That’s why I have so many boxes of B&O in my spare room!!

[Guy]

Seems to be running fine on my 32-bit Windows 10 also

[Author]

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