Forum Replies Created
-
AuthorPosts
-
BRONZE MemberI would still suspect the muting contacts. They should be cleaned and adjusted as per the service manual available at https://beomanuals.com/manuals/Beogram/Beogram%204000/Beogram_4000-Service_Manual.pdf.
Check out the service manual available at beomanuals.com.
Glad to see you are making progress. Are you able to start the turntable using the < key to move the arm inward? Does it stay or want to go back and shut off?
There are some major issues there that can only be explained by one or more errors in your parts replacement. Pressing 33 should ONLY cause the platter to rotate and not move the arm. It is a “clean record” function. ON should cause the collector of TR12 to latch high (17v). If pressing 33 is causing that then I would carefully check your diode orientations as you may have one in backwards or a shorted one. The slow return could also be your pulley alignment, lubrication or servo belt. If it is running at the same speed as “>” then once again there may be a diode/trans issue. This is when TR13 should latch high. Finally, don’t forget to check D9/10 and TR8 on the muting board as they perform the same functions.
To do a fair comparison I would still connect the 3500 directly to the 28s.
You likely have a shorted transistor in the On portion of the electronic sw. Check TR13 if I remember correctly. There is also a companion on the muting board for the remote.
First, which RIAA preamp are you using? I would definitely try a direct connection to the line in of your BL28’s bypassing the Moment.
Yes that is what I meant. I do see that Martin has an 8002 Cap kit at https://www.beoparts-shop.com/product/capacitor-kit-beogram-6006-8000-8002/. I have gotten parts quickly from him in the US.
You can’t get a “set”. You need to get a cap kit that includes all the values you need. These kits are available on Amazon, DigiKey, Mouser, etc. Only do the electrolytics (the cylindrical ones) first as they are the most likely culprits. Don’t forget the 47mF on the CPU board.
I doubt its the motor as its on the right as is the transformer. My suggestion would be to open the unit per the manual at https://beo.zone/media/files/Bang-Olufsen-Beogram_CD-5500-Service-Manual.pdf and identify the specific component generating heat.
No I did not check this because there is audio on the speaker pin. I would expect that an issue with the muting relay would prevent audio from passing to the speaker port. As far as I can see it is much earlier in the signal processing? When I trace the audio there is a signal on the output pin of the speaker port. This signal dissapears when I attach a load (speaker) to the port. I can’t see any damage on the port, there are no shorts on the pins. Voltage of 4.5v on the pin for the dataline seems correct.
By your earlier statement the Rt Spkr Jack (P91) works so there is no other likely failure than the relay. Anything eariler shares the audio path with P91. Datalink is not involved in the audio path.
I’m not sure what that circuit board’s function is as it’s markings and wiring could indicate that it is on the power amp outputs. You definitely have a defective left channel if it is reading 24v. That is also the channel associated with the R101 that you replaced. Fix the left channel first and you may find that the right channel no longer makes noise.
The transport screws are not used to adjust the leveling and do not come out so they are not likely stripped. The screws to level are under the platter. Take a look at the service manual at https://beomanuals.com/manuals/Beogram/Beogram%205500/Beogram_5500-Service_Manual-version2.pdf for instructions.
Are you certain it was R201 3.3K ohms that was burned? I ask because that is a series input resister to the power amp IC and i can’t see it getting the current to “blow” it. If that is the resister, could it have been cracked instead? As to the noise can you describe its character. Can you check if you are getting a DC voltage on the output with the speakers disconnected?
Those were power darlington transistors. You can use BDX33A and BDX34A to replace them.
I would check the 12v supply. You may have bad caps at C3 or C4. Make sure you have a clean 12v at the solenoid. TR6 regulates the voltage to 5v for the motor so it would not cause this issue. There may be 120Hz noise on the 12v line.
Based upon Beolover’s sample, that separation was caused by force. Note that there is thin film residue to the old bond indicating that a shear force will likely be more successful than heat softening. This would call for a non-marring mallet with the platter supported thru the center hole. You could also try a .1mm stainless steel spudger to work around the edge to break the bond.
I would not try as the two pieces are bonded. Applying heat to relax the bond would damage the ribs.
Christian, I’m afraid the 8002 had a different bearing yet again as it was a different drive system.
I believe the confusion is due to the 4002 having two different bearings. The earlier 5503 types had the platter from the 4000 which had a ball and thrust pad. Yours is the later one which had a lighter but larger black subplatter and only used a centered point. In any case, there does not appear to be anything missing.
-
AuthorPosts