[hcraig244]

Ok

Your tracking servo is working fine, the servo is only activated after the tone arm is lowered..check out the video Belover posted on U tube for a good explanation of the circuits involved

craig

 

[hcraig244]

The vibrations you mention could be caused by a number of things, I too have used silicone grease on the threaded shaft, however i removed it from the rails as it was collecting dust and although not causing any noticeable issues i felt that it wasn’t necessary, look to the drive pully and its alignment to the motor spindle pully, also check that the threaded shaft is not bent….i have seen this in the past. Regarding the clicking sounds on the return run this will be the slider contact switches getting operated as the arm returns, you wont normally hear this on the way in as the arm moves relatively slowly compared to the run out.

enjoy

[hcraig244]

Ok

So the coil is ripped and in your opinion beyond repair, shame but still not impossible to repair…just difficult. As chance would have it I do have a woofer purchased some years ago when I was going through a period of interest in repairing them, I bought it in case I couldn’t master the re-location of the magnet dislodge problem that has plagued these older speakers due to glue degrading….turned out I was successful and didn’t need the one I bought…so still have it, thing is I cant remember what I paid for it ;¬)

Craig

[hcraig244]

Sounds good to me, I’ll have a go at sorting it. Send me a message and I’ll organize postage costs 👍

craig

[hcraig244]

Starting point may be if the coil is still measuring 4 ohms?

craig

[hcraig244]

Ahh…..that’s unfortunate, had it just been detached magnets I could have repaired it for you, damaged coil is most likely to be terminal

craig

[hcraig244]

Hi

Whats wrong with the one you have?

Craig

[hcraig244]

Considering the age of these decks, and the complexity of operation its not surprising that they demonstrate the occasional temperamental slip, I have found for the most part I’m constantly tweaking and adjusting this and that in order to maintain continued operation….it’s all part of the charm ;¬)

[hcraig244]

I’m pleased everything has worked out for you….however the correct adjustment of the diff stop is identified below, buy hey if it isnt broke dont fix it ;¬)

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[hcraig244]

Have a look at Rudi’s video below….could be the ES (End Stop) switch playing up.

https://www.youtube.com/watch?v=UdJ7G1e_LdM

[hcraig244]

All of the above are the reasons I hold the vintage equipment in high regard, the BM6000 quad is a master class in over engineering, the lengths the B&O engineers went to just to make the indicator ribbons move up and down is staggering…and the logic gated control panel of the BG4000, given it’s primary role in life is to drop a stylus onto a rotating disc is also the work of someone with far too much time on his hands……

craig

[hcraig244]

I have a Beomaster 5000 which when it came to me had a replacement rectifier fitted now I come to think about it……

Craig

[hcraig244]

By the way…..the BM5000 is a cracking tuner, there is some evidence that the BBC once held three or four to use for monitoring the strength and quality of the signals transmitted back in the day.

Craig

[hcraig244]

Are you sure the lamps you have purchased are specifically for the BM5000 tuner? wrong mA rating plays havoc with BM4400 tuners, I dont have a circuit diagram for the BM5000 tuner to hand but do have one somewhere…make sure the lamps are correct (check with Martin AKA Dillen from this site to confirm)

Craig

[hcraig244]

Beautiful cabinet work….and attention to detail cosmetically…..I would have liked to see/hear more about the rest of the restoration work both electrically and mechanically, I’m imagining it will have been extensive considering the condition of the cabinet when it came to you…please detail the process you followed for this for our continued entertainment ;¬)

Craig

[hcraig244]

I’m struggling to access the product manuals….is there an issue?

[hcraig244]

Was TR210 that had gone down….general purpose transistor BC559….changed it out with a BC558 and was rewarded with a working right channel……love that transistor tester.

[hcraig244]

Unfazed by this conundrum i connected up my scope and started to trace the signal path through the right channel….in the past i have connected a signal generator to C200 of the amplifier and checked for the signal at C232 and worked back until i find the signal and replace the defective component….this time i simply plugged an antennae into the set and tuned to a strong signal and using the working left side as a comparison did the same as i would with the signal generator….found this little fellow had failed

[hcraig244]

In my defence it is difficult to solder under the support that runs above the components in that area…..I’m unsure why that would cause the working let side channel to go blat, blat, blat rapidly….but when i resolved the issue the left channel came bach to life….Martin can you explain?

[hcraig244]

Hmmmm….looks like we have lost a post or two in the transition, not to worry. Repaced most of the capacitors and decided to power up and check everything is good before pressing on, and to my dismay things had taken a turn for the worse!…..the right side channel still didn’t work and the left side made a sound like a wooden stick poked into a bicycle wheel….sort of a rapid blat blat blat noise, very disconcerting. Had to be something i had done…so had a close look at all the solder connections and found I had been a bit to enthusiastic with the amount of solder i had applied to one of the connections…four points had flowed into one instead of only three…

 

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