ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
hello beo world..
I'm new here but I fulfilled my dream so I came ...
I recently bought an almost non-functional beocenter 9500. I fixed what I could but I still have a problem with tape deck1. Often the tape deck does not start after connect the main power cable . only the dolby light is on, which cannot even be switched to b or c. I feel that this is due to the modification, that is added to the tape controller board. Do you think removing this board will help and what exactly is it? Otherwise everything goes ok .. thank you for every advice ..
Hi
I've had quiet at number of Beocenters open, but never seen this kind of modification.
Looks a little bit like a B&O modification, but the 2 x 2 big parallel resistors on the left looking suspect.
I could not see the number of the resistors but they seem to be on a small value under 180 Ohm and I can't imagine where and for what this 5 Watt resistors are requiered.
Maybe Martin can solve the mistery of this piggy board and the resistors.
Kind regards
Christian
hi Christian
Thank you for answer
There are 4 resistors connected in series.. 2 + 2
interesting that the problem is only with the tape deck. It does not affect anything else. At least I haven't found anything else yet. There are no modifications elsewhere and everything is OK, except for some mechanical imperfections that I solve ..
sometimes the mod also jumps when the display shows dolby B + C and reverse mod loop (two arrows). So the cassette goes all the time around. There is also the AUTO led light. AutoRev does not switch anything on the keyboard. NR switches modes but chaotically. I do not know. Correctly, according to the manual, there should probably be only one arrow and one dolby? ..
rasto
I never saw that modification before.Can we see the serialnumber label?
Martin
I'll take a photo of the evening and send it
HI
ok..here is the serial number...
and more detailed photo of integrated circuits..
lm393n - analog comparator
hef4066bt philips -analog switch..
today after plug main power cable 9500 began to behave completely normally. Dolby and autoreverse where it should be .. the cassette can be started..
rasto..thanks for your time...
my wife is already unhappy that I pay more attention to 9500 than her ... :-)
Hi Rasto
BTW don´t forget the bridge plug into the LINE IN/OUT socket. otherwise, frommy experiance, you will not hear anything from the speakers because the preamp section and poweramp isn´t connected anymore.
hi
yesterday my tape recorder didn't start again and the light just dolby without it being possible to switch it
Maybe there are two possibilities to get the tape back to work.
1. Cut off the additional PCB from it's wires and leave a little pice of the isolation so that you can solder it back to the connetion points if nessecary.
Look into the service manual for points where traces maybe have been cut.
Look for the 4 big resistors and solder back to original values.
It's quiet a lot of work and you have to be experianced reading the schematic.
2. Feel free to ask member dillen (martin at https://beoparts.com) for a spare PCB so you could start from scratch with a original PCB and look what comes up.
CHristian
thank you Christian
I will try the first one, I would just need a photo of the PCB model 2506. and the value of those four resistors .. I am going to look for..
Just downlod the requiered servicemanual, there you'll find the information you need.
Follow the soldered wires if there are some traces cut, vias removed or other aditional parts like the capacitator on the backside.
I don't have a photo at the moment but maybe there is someone else who can help wit a picture of the area where the modification is made.
Best regards
one more suggestion
maybe it could be a control PCB from another Beocenter 8500 or 9000 wich was modified to run with the tapemechanism of the Beocenter 9500.
I haven't looked if there are differences on these board because there are not a lot of pictures to find with a detailed soluttion.
Here is a picture of a offered Beocenter 9500 tape control board which has some different plugs and sockets and I'm missing the 4 big resistors and the plug with the thin white or grey wires normaly going to the tapedeck.
https://masterplay.eu/our-products/our-products/beocenter/our-products/beocenter/beocenter-8000-8500-9000-9300-9500/beocenter-9500-tape-control-board.html
This is a picture "stolen" from Beoparts shop of a Beocenter 8500 control PCB
https://beoparts.com/2014/07/11/beocenter-8500-tape-controller-pcb-board/
Seems to be not as easy with the different versions.
Is there a partnumber on the PCB of your Beocenter?
yes, I've seen it before. but neither the manual can be used very much because I can't find the parts even by the number on the board. it seems that the resistors you didn't like are probably okay and are almost related to power. this added board probably controls the logic of dolby and probably allows you to turn on dolby b + c at the same time and also a loop of playing cassette. I'll look at the interruptions on the board and let you know ..
hI..
I cut the pig board and put the board in a original state. there were three interruptions ..
problem with chaos on display is solved but the problem with plug main power cable remained.
1. sometimes okay... after connection the main power cable all functions of tape deck are alright. capstan capstan is spinning. I switch the device to standby. I turn on the device and tape deck is ok.
2. it's not okay... after connection the main power cable, the capstan is spinning but on display light only the DOLBY light without b or c, side 1 doesn't light, the record doesn't light. rew/ff no reaction. nothing is changed after switching on from standby mode.
3. it's not okay2..after connection the main power cable, the capstan is dont spinning, on display light only the DOLBY light without b or c, side 1 doesn't light, the record doesn't light. rew/ff no reaction. nothing is changed after switching on from standby mode.
You think it's fixable? thank you for any advice..
and regarding resistors...
I can't find the four resistors in the service manuals .. the number on the board is r538 / 537/544/543 but I also didn't see it there. Probably a different board design. because on the board resistors are connected in series, but in reality the connection is skipped and connected to the end and the beginning.
and it seems to me the soldering as original, not how the pig board connections were made
I don't know what that modification does or why it was made, but it looks factory.Is the processors memory backup battery good (no less than 3V DC)?
hi Martin
thanks for your answer
the device remembers radio stations and time on the clock after unplug Main power cable.. only tape deck make problems. Also in testmode everything was OK .. can it still be a battery? it seems to be still the original sanyo. does not even write co.de
But sometimes when the tape deck is turned on, there are only five bars on the display
but I'll try to measure the battery anyway and I'll let you know ..
Seems that the mod board had no function at all, the errors and issues are the same when I read right.
That's the first good step.
I've had a Beocenter 9000 with strange behavior like flashing LED's when switching between the "SOUND" modi, FM station were not stored and maybe some other strange stuff.
For me helped a "DELETE RAM" like it is written in the service manual: "TESTMODE" > KEY 7 > DISPLAY SAYS 1 > switch to STBY
Good luck
hi christian..
by disconnecting the board I solved only the problem when the autoreverse loop was turned on, and dolby b + c at the same time
thank you for your advice.. can i do it without remote?...
ok..
I measured the battery and the value is 2.932V .. So maybe it will be the battery.
I tried resetting the ram memory today but it didn't help ..test ram is ok..
This is my day.
The mystery is solved. The problem was in connector P35 pin 3. Poor or oxidized soldering.
It's a good thing I looked under the insulating paper when I was looking for the missing voltage on the connecting connectors.
And I already wanted to change the battery..
Everything now works on the first connection of the main cable...OK.. I'm going to look for gramo...
thank you for every advice ..