BeoGram

Re: RE: B & 0 4200 not powering up

Beo4002 — Thu, 22 Oct 2009 19:45:27 GMT

Hello,

My TTT (Beo 4002) has the same problem. I want to change the transformer but I don't know how many volts it do.

Someone have the answer ?

Re: RE: B & 0 4200 not powering up

burantek — Wed, 21 Oct 2009 08:56:08 GMT

movingcoilguy:
I may have to find a B & O tech as there should be one in Toronto?/ thanks Daren

If you decide you want to move onto a technician, there are some in Toronto listed here by a very reputable BeoWorlder.

Re: RE: B & 0 4200 not powering up

movingcoilguy — Wed, 21 Oct 2009 08:43:23 GMT

Hi Mika and Peter, just an update I installed the new fuse and it blew so I guess there is a much more serious problem. Maybe the power supply or the circuit the fuse supplies has a short or something? It was worth a try but I guess it is back to the drawing board. I may have to find a B & O tech as there should be one in Toronto?/ thanks Daren

Re: RE: B & 0 4200 not powering up

tournedos — Tue, 20 Oct 2009 15:51:51 GMT

I wouldn't bother with the Variac. That is mostly useful with long unused tube radios where the electrolytic capacitors have lost their insulation barrier and just banging the power on can destroy a lot of stuff. It should not happen with later low voltage circuits like this, and the deck will not work correctly with a too low mains voltage anyway.

Note that I'm still not explicitly telling you to power it on - I'd like to be there myself, but I'm pretty confident you could just try it

Re: RE: B & 0 4200 not powering up

movingcoilguy — Tue, 20 Oct 2009 15:38:38 GMT

OK Mika, I will take your advice and proceed with caution. I have done a little bit of electronic work before but I am rusty but do have a multimeter etc. I also have a variac, being that I have no way of knowing how long the unit spent in the attic and its previous owner was around 90 when he died do you think hooking it up to the variac and bringing it up slowly would save any of the circuitry from frying? The other fuse was fine maybe that means something ? I did notice on the bottom of the shinny side of the platter that there were some slight brown marks as if something was throwing a bit of heat. Not tons mind you but enough to discolour the underside of the platter in a couple little spots. Daren

Re: RE: B & 0 4200 not powering up

tournedos — Tue, 20 Oct 2009 14:56:22 GMT

315 mA vs. 250 mA is not a big difference, normal fuses aren't any precision components anyway... I would just try it - if you see the LED light up, let it stay for a few seconds, unplug from mains and feel if anything got hot. If not, repeat with a longer try. It if still doesn' t heat up anywhere, try to start it. The main regulating transistor of the power supply is mounted separately on the frame near the motor, that might be a prime suspect to heat up if anything is drawing too much current.

This is all very unscientific and will only succeed in the lucky case there's actually nothing wrong with the circuitry. Optimally you should have a multimeter on the power supply and see if the voltages are correct. Which would mean you'll need to have the schematics - have you done that kind of work before?

Re: RE: B & 0 4200 not powering up

movingcoilguy — Tue, 20 Oct 2009 14:28:00 GMT

Hello, Peter I didn't know that about the B & O cartridges but it makes sense as they are extremely small. One more dumb question if I may? The store as I suspected didn't have the exact match , I believe it was a .25 that I needed the closest I could get was .31 and I thought that would be close enough but thought I would run it by you or Mika before I took the plundge. Daren

Re: RE: B & 0 4200 not powering up

Peter — Tue, 20 Oct 2009 12:02:39 GMT

I note your user name by the way. Did you know that the cartridges used in the B&O range are neither moving magnet or moving coil? They are similar to the Decca range, being Moving Iron with both fixed magnets and coils. The huge advantage is a tiny effective tip mass as all the stylus moves is the cantilever and the Moving Micro Cross.

Re: RE: B & 0 4200 not powering up

movingcoilguy — Tue, 20 Oct 2009 12:01:11 GMT

OK, well that is good too know, thanks again MIKA and Peter for all the tips ! I will keep you posted on the outcome once I source a fuse. many thanks Daren

Re: RE: B & 0 4200 not powering up

tournedos — Tue, 20 Oct 2009 11:39:02 GMT

movingcoilguy:
Hi Peter, thanks! there is 1 4" long grey metal cap that says 1000uf on it but only 1 .

You probably have one of the later DC motored models then.

Since the fuse disintegrated in your hands, it may have been mechanically faulty and snapped the fuse wire during transport or something. I would just try a new fuse - but only the correct rating, and only once! If it blows as well, we need to find the cause. Any good electronics store should have those fuses if you don't find one in your stash.

When you replace it, look for the power indicator LED before trying to start the turntable. If it remains on after you plug in the mains, it will help to isolate the problem - if there indeed is any - a little.

Re: RE: B & 0 4200 not powering up

movingcoilguy — Tue, 20 Oct 2009 11:19:29 GMT

Hi Peter, thanks! there is 1 4" long grey metal cap that says 1000uf on it but only 1 .I may have trouble tracking that fuse down around here but I know I have thousands of fuses and parts as I just cleaned out an estate of an old audio repair shop guy and have boxes and boxes of parts for just about everything except B & O tables unfortunately. Our place is listed for sale ( its a church actually) and I just packed up most of that stuff for storage and that included a huge commercial box of fuses all sizes ( just my luck) I might be able to find the exact box otherwise I will hit one of the chain type stores. its a .25 so will see how hard it is to find. the belt and needle are OK so I will have my fingers crossed. Thanks for the info on the other tt it makes me feel better! It was too bad about the speakers as the tuner and amp would have been great to have with my Rosewood Danish furniture. Cheers Daren

Re: RE: B & 0 4200 not powering up

Peter — Tue, 20 Oct 2009 10:50:41 GMT

Mine don't have switches either so don't worry about it! We do have most of the 4002 service manuals on site if you join as a silver member. These are lovely decks - better made than the 8000 you missed! You could just change the fuse - it may be that it had just broken but on the whole, the fuse blew for a reason! Worth a try though! The types differed slightly for different markets but in the case of the 4002, this will just be the power transformer. There are two very different types of 4002 though - one with an AC motor and one with a DC motor. The AC motor types are earlier and more complicated - recognised by some huge capacitors under the platter!

Re: RE: B & 0 4200 not powering up

movingcoilguy — Tue, 20 Oct 2009 10:42:10 GMT

Hi Guys, thanks for your quick replies and answers. I have got the unit apart as I do have some keen mechanical sense. The small fuse on the right is blown,not sure what could cause this but when I removed it the metal end came right off which may be nothing but I thought I would mention it. As far as a switch at the back I am not sure this unit ever had one but I did notice a spot on the right hand side which appeared to be a spot which may have had a switch or something there just under the wood section. It appears to have been covered over at the factory with some sort of very thin professional tape or something as it is near invisible until very close inspection?? I will try and track down that fuse I guess and see what happens? As well Chris if you want to move the thread by all means as a Newbie I was unsure where the best spot would be to post my questions but have since found a wealth of info on the site. I have lubed many of the points mentioned on a post well I have it apart I thought it couldn't hurt. I must say a great piece of design work and you got to love the way it gives you quick and easy access to the internals which at first glance looks like a very complicated endevour! I have always been a great fan of Danish design as I have multiple pieces of the furniture, they just got it right all a round it seems! Maybe the version I have of the 4002 was slightly different for the north american or Canadian market. as after double checking there appears to have never been any switch on this unit on the back, would there have been different versions as far as the switch goes?????? many thanks Daren

Re: RE: B & 0 4200 not powering up

Medogsfat — Tue, 20 Oct 2009 09:09:50 GMT

tournedos:

BTW did you notice the main power switch in the rear? That problem would be even easier to fix

Good thinking Mika!

If you want I will move this thread to the Beogram section where it will probably get you better answers and won't fall off the end of the page which is likely to happen in a day or so in the General section.

Chris.

Re: RE: B & 0 4200 not powering up

tournedos — Tue, 20 Oct 2009 09:05:57 GMT

Hi Daren,

if you have any problems with further disassembly take a look at this thread.

These are fairly complex machines electronically, so there can be a multitude of problems causing it to play dead - but check the fuse first, it's easy. You should have a red LED lighting under the front of the deck if it gets power at all.

BTW did you notice the main power switch in the rear? That problem would be even easier to fix