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I had some Beovox S60 speakers for a while that i bought for £35 and recently i bought a Beomaster 4000 as faulty to go with them.
The problem with the Beomaster 4000 is that the radio function doesnt work, it just sounds like static and none of the presets or the slider change it. i had a quick look inside and didnt see anything that wasnt attached so i thought id ask here.
here is demonstration video by the people i bought it from: https://www.youtube.com/watch?v=EstiE5Nipiw
some of the orange capacitors in it also look a bit leaky, is this something to be concerned about?
here are some hi-res pictures i took today: http://aristomuy.co.uk/bm4000.html
Welcome to the forum, I made my BM 4000 a couple of years ago, here the thread. I changed all the electrolytic caps, all the trimmers and lamps, some of the end amp transistors.
First of all I would check the supply voltages and idle current, if you have a scope try to find out where the FM signal disappear.
The trimmers on your pics looks very bad so probably you will find some problems there.
I got everything I needed from Dillen on this forum, he has cap and lamp kits, and if needed transistors and trimmers, find out what is needed and contact him.
Good luck
Collecting Vintage B&O is not a hobby, its a lifestyle.
I love the high resolution pictures. Thanks for posting those. As Søren said, an overhaul is due on that receiver and Martin (Dillen) can supply a kit for that.
-sonavor
aristomuy: The problem with the Beomaster 4000 is that the radio function doesnt work, it just sounds like static and none of the presets or the slider change it. i had a quick look inside and didnt see anything that wasnt attached so i thought id ask here. here is demonstration video by the people i bought it from: https://www.youtube.com/watch?v=EstiE5Nipiw
Thanks for the responses guys. That video was made by the people I bought it from so I'm not sure if they used an antenna. I did plug my TV antenna into it which is a rabbit ears antenna that is in the attic and I plugged it in to the community antenna socket. Is that the correct way to do it?
Is there a downside of not giving it an overhaul as in its current state as just an amplifier I can't fault its functionality, there is no difference in volume in each channel and it sounds perfect and I don't want to risk ruining that, I know ill have to at some point though.
Could the radio problem be because of bad capacitors? I don't see any electrolytics on the radio side so I didn't think so.
Is there any faults you guys have heard of before that I could check?
Thanks for your help with this,
Ethan.
The antenna is OK, normally you will only need a wire strip if you are near the sender, I see on the FM PCB some bad trimmers and at least one cap, and 2 or 3 black drop formed transistors that I would change.
On the the preamp PCB you will find more bad trimmers and some caps.
Your sound will not be worse changing caps, in mine at least the half was way off specs, even when the cap looked good, these ROE caps are known to cause troubles, and better change them now, than wait until they go totally bad and maybe destroy other components
Looks like one or two of the skeleton trimmers have already been replaced at some time, they all look suspect and you should change them soon as possible, you can also see some of the caps are leaking........how do the big power supply smoothing capacitors look? I have had a BM4000 that had some leaks from these too. I dont know if this will cure your radio problems (probably not) but it will certainly be a good move for preserving the functionality you currently have, Post some pics as you go on ;¬)
Craig
Thanks for the responses. If I change the trimmers how will I know where to set them back again?
Also could the problem with the radio be that some of these are set incorrectly?
The large capacitors by the mains side didn't look leaky, the transformer does hum but it doesn't really bother me.
Today when I turned it on the switches weren't working correctly as shown in this video I took: https://www.youtube.com/watch?v=UaYvP5QFCIg
Most of the trimmers can be set according to the manual, with the help of a good DMM (Digital multi meter) on some of them you will need more sophisticated instruments. Before I got my scope and function generator. I checked the trimmer settings after desoldering and set the new ones to the same. I do the same with all trimmers if the old ones are set near the middle not totally to max or min.
The switch problem is probably just a good cleaning and lubricating of the mechanics
The big caps are probably OK but I would change them anyway, Remember you will have to change all the ROE caps anyway so why not go for them all (all electrolytic caps)
If you dont know anything about electronics, has no soldering skills, has no tools or instruments you should stay away from it, and find someone who knows
Such high noise level means that the IF probably is working as it should.
I would suspect the tuning voltage.The first thing to check is the 22V stab TR10.
where can i find documentation of what the trimmers do?
i know an average amount about electronics but not that detailed and i am fine with soldering.
to measure the 22v from tr10, which two points should i put my multimeter?
thanks for your help, ethan.
The servicemanual will tell you all the alignment points and which instruments (signal generator, scope, voltmeter etc.) you need.The rest are basics from the years of your electronics tech education.
But you cannot make those trimmers work. They will need replacing, as will the electrolytics.
Martin
The other thing to look for in the FM section are the 2 hidden trimmers (10K 50K) behind the Tuning indicator light, soldered through 2 layers of flex PCB. Although these are much more accessible than the same trimmer in the BM4400....
If that trimmer is shot (very likely), no FM works.
Extreme care is required to not split the flex PCB, and not damage it from heat either.
Recommended replacements are Piher PTC10 sealed cermet units.
Also, if you're planning on doing a full RF alignmenet, IIRC there are a couple of coils which were factory set, and the Service Manual specifically cautions to NOT adjust those coils at all.
Menahem
Guys, does anyone know what type is the TR10 transistor? I'm confused, cause in my manual I find three (3) types corresponding to the part number 8320161: BC261B, BC212B-L and BC251B.