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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi Beoworld
I recently bought a Beomaster 3300 with a set of RL35 speakers. I actually bought the set to get the speakers, which are in good condition. Price 45 dollars.
The problem is the Beomaster 3300, which do not power up but turns on some of the lights. I find it a shame to throw it away and have started a mission to repair it. I hoped to find some help at this forum, but I have not been able to find what I was looking for, despite my thorough search of the current and archived threads.
It started out with no lights at all. After resoldering TR46, 39 and 40 some lights started to glow.
For now I have checked the following:
Fuses - which are ok
Power draw - which is approximately 5W (starts at 10W and stabilize at 5-6W)
Switch seems ok but is not getting any voltage - less than 1V
The lights that turns on are most of the volume lights and if i look very closely I can see some of the function lights as well.
Checked the transformer - Voltages at the secondary side(seen from the above)
Left side coil:
- between black and gray = 25,5V
- between black and brown = 10V
Right side coil:
- between black and brown = 9,8V
Checked the transformer again with the gray and brown wire de-soldered from the secondary side (both coils)- Voltages at the secondary side(seen from the above)
- between black and brown = 9,7V
Powerdraw is now 2W (with the wires detached)
tools at my disposal:
- AC/DC power supply (24volt/24volt)
- multimeter (Ohm/amps/voltage + transistor pnp and npn test)
- Soldering iron
- schematics (for beomaster 2200, 3000 and 3300)
Would any of you have any idea what could be wrong with my beomaster or any hint to where my next step should go?
Are there any typically faults I should consider?
Any help will be highly appreciated!!!!
BTW: Of other side projects, I am currently refurbishing a set of RL140 and a set of CX100. Both need needs new foam surrounds.
Thanks in advance, and thanks for an awesome forum!
Beomaster 3300 is not supposed to light up all the lights.Only the selected functions, the current volume setting etc. is shown.
You tell us it has "no power" but also that some lights are on.What exactly is not working ?
The schematics you found are for what ??? Beomaster 2200, 3000 and 3300 are all very different units.If you need a service manual, make sure you get the right one.
Martin
Correction. The switch has 25 volt at both "legs" but does not switch.
Nothing seems to work only some light. None of the buttons respond. I have the one for 3300. I was told that the three units are almost the same, so i downloaded them all. I am currently using the one for the 3300 unit.
Difficult to diagnose at distance.
Do you have the -33V and +33V voltages on rectifier D23 ?Any reaction to the remote - if you have it ?Does the tuning discriminator react when you tune in on FM ?Speakers attached to speaker sockets pair 1 ?Do you have any sound at all from the speakers ? - A thump at power on or even just a faint click when changing source ?Does the volume control indicator climb up and down when you try to adjust the volume ?
Good day,
I know that this one here is quite old but I hope it is ok that I put my question here instead of opening a new topic. My problem is quite the same as it seems:
What I have: Beomaster 3300 Type 2951, bought as non-working off ebay, I have no history about the unit
What the machine should do: Satisfy my ears with great sounding music
What the machine really does:
- I can turn it on and volume lights and source lights come up as they should do
- No sound coming out of the speakers or the headphone jack, no matter which source I'm selecting. Nothing to see on the scope when I stick it across the speaker terminal. Selector set for one pair of speakers of course.
- Tuner seems not to react on anything (at least stereo light should come up when I dial through with antenna connected?)
- Fuses F2 and F3 keep blowing immediately after replacing with new ones (seems they are the ones for the amp section)
I have measured the rectifier D23 on the big PCB and it measures fine. Also some other diodes tested but no shorts or open circuits noted on my meter. I wanted to replace the two big caps as they might still be the original ones. I don't see skidmarks on the board that could tell me that anything has exploded or cooked. Also smells ok. Cooling compound on the backside heatsink for the STK and TR39 and TR40 is completely dry, but that should be a minor problem to put some new compound there. Insulation plates for those two transistors also correctly positioned.
Can anyone point me the way to start off first? Any common parts known that I should check first? Have a schematic on hand and a soldering station and multimeters and so on. Already saved a Kenwood KR710 which had a water damage but the Beomaster is a way more complex unit than an old Kenwood xD
Thanks in advance for any useful reply. Don't want to let the unit die because this is a great piece of HiFi history ;-)
It's quite common for the output amplifier i.c. to fail in these Beomaster's.
It's a single device with both channel amplifiers in the same package(IC100 as marked on the pcb).You can get to it's connections by removing the bottom plate of the unit.
You should have +33v at pin 11,and -33 at pin 9.If these voltages are present,you should hear some noises via the headphones when you touch pin 1,which is the right hand input to the ic.
If no noises as above,check safety resistor R123 (100ohm)
btw,speaker 2 output is controlled by a manual switch inside the pop up control compartment.
Replacement output amplifier ic's (STK4151-5)are readily available.
Speaker repair kit's are available for your speakers,but the RL140 are rather "big boy's" to use with the '3300!
Nick
And dont buy from Asia. it’ll be counterfeit.
Hello Nick and Martin,
thanks for your replies. I just ordered a new STK from kessler-electronic.de which is a supplier for electronic parts here in Germany. They have some in stock and my hope is big that they are not selling this so called China-crap. Also this should be new old stock item, not a pulled module. Once it arrives I will install it and make a test run and also take a look at the voltages mentioned by Nick.
Will keep you posted about progress. Have a nice day guys ;-)
New STK arrived just today and looks brand new! No old solder on the connections or any scratches on the surface. Hope my wife allows me to install it this Saturday. Can't wait to see if this really makes my unit play how it should do. Keep you guys updated in any case. Have a great evening!
Cant wait to see what happens, I have one BM 3300 waiting, no sound in left channel, and tell your wife that this is important maybe she can help a little
Collecting Vintage B&O is not a hobby, its a lifestyle.
My wife was working longer today so I took the chance to replace the STK. Also checked R123 (which is 99.9 Ohms in my meter), replaced the two fuses and plugged it in. Fuses burnt again immediately so I decided not to do the noise test ... Failure must be something else, not the IC I believe. How about transistors in the heat sink? Couldn't these be the failure in my unit?
Happy for all replies ;-)
Don't despair sir!
You now have to methodically check through the system.
If F2 and F3 are still blowing since replacing the output chip,it suggests that D23 the bridge recitifier or OC1 or 2 may be short circuit.These components form the supply to the output stage.
Incidentally,is the unit set to the correct mains voltage?
Despairing? Me? Never, this unit is worth every drop of sweat to get it back to life ;-) The construction itself is a masterpiece of art and even I never heard how it sounds I'm pretty sure it will be an amazing experience. had a BM1200 years ago and this unit took me to orbit already with its sound ;-) Wonder what the BM3300 will do to me ;-)
Had a look at the 3300 yesterday again and found that the capacitors look suspicious. One is a 6800@40V which seems original and the other one is a 6800@80V. This tells me that somebody was into this unit and only swapped out one of the two caps. Have ordered two new caps with 6800@35V to replace the both. Have no ESR Meter to check them but what I have in my unit just doesn't look right. D23 was checked but I did that in-circuit. Will unsolder it and re-check again out of circuit to be on the safe side.
Keep you guys posted about progress. I'm happy that I have signed up here. Already went through half the workbench-forum ;-)
I would suggest fitting 40V or 63V capacitors rather than 35V.They'd be working too close to their max voltage rating.
Hello Martin,
just checked my order again. I ordered 6800@63V. I was looking at the voltages that go across the PCB and indeed 35V caps would be driven close to their limit. Once arrived I will replace the old ones and re-check again. Makes no sense to me that only one cap was changed ... But tells me that a pro was working on my unit before :D
Good evening,
the new caps came in today and I just got them in. Still blowing both fuses? I sticked the meter across ground and the contacts of the rectifier D23 and have found about +25V on one contact but nothing on the others. So the voltage comes from one of the caps because the Beo wasn't plugged in anymore at that point. Shouldn't I see negative supply voltage on the rectifier as well? After unsoldering the D23 I found that it looks fine on the meter, no shorts there. Any thoughts?
Many thanks in advance and a great weekend to everyone ;-)
Nick was asking if the voltage selector is set correctly. Don't have a selector but the label on back says 220V @ 50-60hz. Measuring what comes out of the sockets I see 235V there, should be within tolerance.
As it seems as though the unit has received attention from A.N.Other in the past,I wonder if the bridge diode is connected correctly?It could of course be breaking down under voltage,so may still measure ok.
Might be worth trying a new known good one?
Are you fitting 4A fuses for F2 and 3?.
There are some filter capacitors across the supply to the bridge rectifier(C65/66,and another across the positive line (C74)I've never had to replace these,but you never know?
The +33/-33 supply only supplies the main amplifier,although there is a feed to the auxiliary supplies too,but this is protected by a fusible resistor(R110)which surely would have blown if the fault were on that line?
You've gone quiet sir,was there a happy outcome to your BM3300 problem?
Dear Nick,
no unfortunately I didn't had the time to work on my BM lately. But I had ordered a new rectifier from a local supplier that is due to arrive the next week. Just to have one in spare in case it really breaks down under load. Doesn't cost a fortune so it doesn't matter to buy one. We're short on staff at work but next week it should return to normal so I can spend more time with the BM again. Also I will look at the safety resistor and have a close look at the PCBs itself for cold soldering joints and will measure the transistors on the back besides the STK. Will be reporting the outcome of course ;-)
Very best regards
Tobias
Hi Toby (Tobias)
As it looks you're located in Germany; may I ask where (north, south...)?
I am located in the "Schwarzwald". If you are close we may look into your 3300 together. I do have an 3300 with burnt processor which we could use as a donor.
Not a lot of time for me as well as I am self-employed so sadly can't dig deep into your BM remotely.
Best,
Gunther
Hello Nick, hello Gunther,
many thanks for your replies. Unfortunately I can't take the chance to look into my BM together with you since I'm located near Hamburg. Last days/weeks I had too much work in the office with people being on sick-leave and so on that I couldn't had the time to look into my BM again. Also the replacement rectifier was sent to the wrong address so I still don't hold it in my hand.
Gunther, If I need some parts that I can't get here from a local store I would like to ask you for donation or selling those parts to me if ok for you? Money for the parts and postage shouldn't really matter at that point.
There were some questions open by Nick: Yes, I'm fitting slow-blow type 4A fuses when replacing F2 and F3. I'll also be looking at C65, C66 and C74 as soon as I have the chance to do so and also check the R110. The other one discussed here R123 showing perfect reading on the meter.
Anyway, won't give up on the BM and just wanted to let you guys know that I'm too busy these days to move on with the BM.
very best regards