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
I just received a B&O 4002 for Christmas from my three daughters that was supposed to be recently serviced, etc., but it won't play any vinyl. Everything works with the exception when the arem goes over and lowers unto the album, it just sits there and plays the same groove over and over. There is no tracking. I can move it manually over, lower the arm, and it will play a different groove, but over and over just the same. It goes to end of album, returns and shuts off. Everything else seems to work well, exceptit won't play.
I've got a manual and service manual I've downloaded. Where do I need to look? Is it in the shutter?Dave
I would first look for the simpler problem. Is the belt on the motor that controls the arm on the pulleys? Is the shell that is in the back of the tone arm and sensor arm seated firmly and not binding? Is the tracking force adjustment set correctly and the tone arm balanced?
John
Yes the belt is on the motor. The arm and detector will go all the way across and all the way back.
I have the shell off so I can see what is happening
The tracking force is set at 1.1 G with a MMC 10E cartridge on it. I have varied that from .5 (the arm would not go down) to 1.5g which made no difference.
I can not seem to get the arm to balance at all. I lift the spring loaded lever off it, run the screw back and forth which moves the weighted arm closer and farther away from center, but the arm never seems like it is on a pivot. In other words, it doesn't seem to be real free. When I opened it up, there was no sealer on the screw, and the weight was almost to the rear as far as it would go (making the cartridge end light). Again, I have messed with it, but certainly doesn't seem to make any difference.
Dave
Hi, to check if the shutter/photocell mechanism is working, remove the pickup cartridge, put a record on platter and press play. If you gently push the pickup arm towards the centre of the record, the carriage mechanism should move to keep both the arms parallel.
Hope this helps, regards Richard
Sticky grease at the arm pivots?
Jacques
I agree with seeing if the photo cell is working - That would explain the symptoms you have. The arm moves slightly from central and this allows the photocell to be exposed which triggers the arm motor. As stated above, remove the cartridge, press play and the arm will move over the record and drop. Clearly nothing will touch the record ! Manually deviate the arm towards the centre of the record and the arm carriage should serenely transverse to the centre. If not, one of the photocell or light bulb have a fault.
Peter
I could not get the arm to move on the lead in groove, but everything else worked (when pressing buttons and bypassing the shutter, everything does well). I took the top off the unit, and found that someone had replaced the screw that clamps the paddle onto the arm pivot with what looked like a drywall screw or maybe a decking screw. I tried adjusting the shutter, and ran out of adjustment before the motor would activate. So I loosened the screw and moved the paddle clockwise on the pivot (after removing the top of the photo cell unit so I could see how it worked) and set the shutter adjustment back to center. I had to move the clamp twice, but was then able to get the arm to track. However, the sound produced by the unit was horrendous, so I looked at the needle and found it to be more round than sharp. I have purchased a used one from flea bay, and will do the manual fine adjustment as soon as it gets here.
This was an interesting problem right off the bat, that has enlightened me on some of the engineering of this unit. Now if I can get the arm to balance properly I will be pleased. I believe I will check to see if I can get some cleaner into what I believe to be the pivot, and then oil to see if it frees it up.