[BMXband1t77]

Hi,

Well thats torn it! I think i have somehow broken or loosened the Phono (vinyl) rca inputs on the back of my amp. Now when i select Phono as an input i get horrendous feedback hum and no signal. Previously it was working fine BUT i had to fiddle didn’t i?

I received a nice quality 5 Pin DIN to Phono socket cable with the intention of upgrading the current rca plug to rca socket bell wire our Rega is currently connected to.

I made the necesary alterations, removing the rca phono input cable from the amp, which was fully switched off at the wall, and replacing it with the new Din to rca socket cable, only to be met with massive feedback earth hum. I quickly realised that there may be a an earthing wire missing to this connection. i hunted around the back of our Rega RP1 only to find NO earthing cable at all!

I turned the amp fully off again, fully removed power from the wall socket and inserted my Beogram record deck control cable, total silence so it cannot be the DIN input at fault, it is the new cable not earthing correctly? I will be sending this back as its no use to me now.

I replaced the old rca to rca socket cable fully expecting normal vinyl playback to be restored.

NOPE! All i got was horrendous earth hum again. Upon closer inspection the Right rca socket on the amp does now feel a little ‘wobbly’ and the hum changes in severity when it is wiggled.

The problem with these amps is there is almost zero room to get purchase on tight fitting cables (see pic) and from me removing and replacing this cable i fear i have broken something disastrously ruining my lovely (and pretty much functioning) Beomaster 5500 receiver!

I need help to get this sorted out and relatively cheaply as the wife has had enough of my vintage B&O resurrection attempts, i fear i may be forced to go back to square one with another system.

i had got these working fine until today:

1. Vinyl playback via rca phono inputs
2. Beocord cassetted deck playback
3. WiiM pro plus music streamer and recaster.

Now i have both Vinyl and CD non functioning….sigh…

thanks for any help and advice,

sheesh I am not having much luck being a new B&O owner am i?

Jon

[Dillen]

The RCA sockets are known to break their solder joints.
They will have to be re-soldered.

Martin

[Die_Bogener]

Soldering on a Beomaster?

No problem.

Remove the steel bottom plate.

1 Minute done… or 30 seconds?

You can even make it run, test, look and measure…

[BMXband1t77]

Hi Martin,

thanks for your response and yes it makes sense i have somehow dislodged the phono rca inputs/ broken dry joints etc.

Has anyone else had this issue here and perhaps posted up how they fixed it?

I have soldered in the past but frankly getting to the underside of the amps circuit board to even get near the solder joints makes me break out in cold sweat!

Do you know if its an easy fix or something i would be best leaving to an authorised B&O vintage service?

If so, do you know of any reputable ones who could give my poor amp a service?

Did you have any thoughts about why the 5 pin Din to RCA stereo socket cable failed?

Is it simply that this type of connection requires an earthing lead connected to the little earthing point on the back of the 5500 receiver?

thanks

Jon

[BMXband1t77]

HI,

it ‘sounds’ relatively easy but is there any documentation to show how/ where the screws are to remove the bottom plate? i don’t want to remove the wrong screws and find circuit boards ratling around inside etc!

would it be possible while desoldering the original rca sockets to upgrade them to newer gold plated ones? i know mine are pretty tarnished and rough/ grippy….which is probably why i ended up having to apply too much force to get my rcs cables off in the first place!

thanks for any help

Jon

[sonavor]

Hi,

This thread I did recently shows the disassembly and reassembly of a Beomaster 5500 receiver. I removed all of the boards for cleaning and restoration.
The link starts with the last post (reassembly) but if you scroll down to earlier posts you will see the disassembly post.

Also, if you don’t have the service manual for the Beomaster 5500 I recommend picking one up. I believe there is at least one for sale on ebay right now.

Hope that helps.

-sonavor

[Dillen]

Don’t get me wrong, but if you cannot see your way out of removing the screws for
the bottom plate, you may want to consider if this repair job is for you.
Perhaps it would be better if you leave it to someone with experience and training etc.

Martin

[BMXband1t77]

AHA!

thank you i see now, once the fm boards placed into service position you can remove the input board via 2 screws at the edges and inspect/ resolder the phono rca inputs sockets.

Would it be possible to get some nicer new gold plated types to solder on instead? my phonos are rough and extemeley grippy, probably why i ended up being a little too firm with them in the first place, i just could not get the rca plugs off to test out my new 5 pin din to rca socket (for putting the rega rp1 inline to the phono record input). this didnt work by the way, i am guessing due to the lack of ground lead from the turntable to earth it to the amps grounding post? or maybe i had already damaged the phono inputs anyway? Not sure to be honest.

what type of solder is best for resoldering these old B&O’s please?

thanks for your more informative and helpful reply.

Is servicing these and other B&O units something you do for others or just for fun?

Looks like you’re thorough at identifying the best bits to replace, or clean.

I still have problems with my Beogram cd 5500 motor / transport / tray too to get round to at some point (please see my rather long winded but nube trying to get it fixed post a few moths ago).

thanks again

Jon

[sonavor]

Regarding soldering (and de-soldering) I recommend researching that. I like to use a 60/40 (tin/lead) with a no-clean resin core. An important thing is making sure you don’t damage the older PCB traces with too much heat (both while de-soldering and soldering). So practice that well before taking on the real task.

I don’t know about replacing the RCA plugs. I don’t use them.
For one thing, the Beomaster 5500 is part of a B&O system. Every component is integrated and controllable by remote control via the Beomaster 5500. You get that using the 7-pin DIN interconnect cables which have the audio signal and remote control signal. Using the RCA connections are just for convenience with a non-B&O audio component and you lose the remote control functionality.
That is probably why the RCA plugs on most Beomaster units are not that great.
Stick with the B&O cables with the DIN plugs. You will enjoy the Beomaster 5500 a lot more if you use it as part of the Beosystem 5500.

-sonavor

[Dillen]

I agree.
And for soldering in areas where vibrations are part of the
day (portables, car stereos, speakers etc.), I like to use solder with a hint of silver.

Martin

[BMXband1t77]

Ok thanks for the tips.

Yes my system originally did have B&O cd player/ tape deck/ record deck connected via din plugs BUT the cd player and the record deck now need service or repair (the record deck needs a complete new cartridge, expensive). I have quite a long post about my problems with my cd player tray operation and drive motor spinning up too fast. Still no firm answers what to do or where to get serviced in the UK.

So meanwhile i have had to compromise and use some of the RCA inputs for namely:

WiiM pro plus streaming player (for streaming from mobile devices to the Aux input)

Rega RP1 (Now utilising the WiiM Pro Phono input via a cambridge phono line converter)

Sony Super Audio cd/ dvd player (now utilising the WiiM pro Optical input which then comes out of the Beomaster Aux input)

I ‘broke’ the Phono RCA inputs simply by trying to remove them to fit an RCA Socket to DIN cable for the Rega RP1, which failed miserably in swathes of feedback hum, i think because of the Regas lack of grounding cable.

So at the ‘moment’ i have patched in the sources i need bypassing the current faulty B&O sources unitl they can be fixed. To be honest it works quite well, having doscoverd the WiiM Pro can ‘listen’ for input sources so swapping from playing a record to a cd it automatically switches inputs, a little like the B&O operation.

I agree the entire system integration is desired but at the moment for me it is out of reach.

thanks

jon

[Author]

Posts