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
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Hi all,
Firstly, Id like to say this forum has helped me get my beogram too where it is today. There is a world of information on here and I often find myself reading for hour on end from one interesting post to a next learning and committing pieces of information to memory, though I my never need them. Up until now I have been able to find all the information I require to get my Beogram back in form.
The issue I am having with my Beogram 4002 Type (5513) is that I have the platter is spinning at 78rpm when the 33rpm button is selected and 88rpm when the 45rpm button is selected.
I have tried adjusting R14 and R15 which made next to no change.
I put my multimeter on the DC motor’s pins and came up with 7.04v when taking a reading from the White and Blue and 5.45v when measuring on the Red and Blue.
My history of repairs on this turntable are as follows:
I re-infusing the DC motor bearings with oil because it was very noisy. At first, I installed the plastic section the brushes screw to 180 degrees and the motor ran anticlockwise. I have since spun this around and the motor runs clockwise. With the screw pattern on the base of this motor it will only screws on in one place that allows all three screws to be installed, so I know this is in its original place. When reassembling I also tested the current of the motor and got a reading of 0.03 amps / 3 milliamps. Which I thought was acceptable.
I had to repair a solder on the PCB when the stop button wasn’t completing a circuit.
I have also Restoration of the Arm Lowering and Tracking Systems
Any ideas or experience with this issue?
Thanks for your time reading my post, sorry if I missed anything please feel free to ask for more info.
(I had attempted to post this earlier and lost my post, so I am retyping this for a second time)
(0.03 amps is 30 milliamps - not 3).
Did the motor run at correct speed before you started work?Did you replace the speed setting trimmers on the main circuit board? And if so, did you replace according to the manual oraccording to what was actually fitted?
Martin
Hi Martin,
Thank you for your response.
Sorry your correct 30 milliamps. 3 would be ridiculously.
Honestly I sadly didn't test if the motor held the correct rpm's before servicing the bearings, I recently inherited this turntable. I also haven't replaced the speed setting trimmers on the main board. Is this a good place to start?
Regards,
Joel
I suggest you diagnose the current problem BEFORE doing any more work.No matter how careful you work, there is always a risk of introducing more faults and that would potentially make it harder to diagnose any of it.
Test - Diagnose - Repair - Restore/Upgrade.In that order.
That’s a fair point. Now that I know of this issue, I definitely don’t want to be adding to more faults to this.
What’s the best way to test and diagnose this issue?
I had thought it might be something to do with printed circuit board that’s on the motor though this looks relatively simple. Like not much could go wrong.
Compare voltages (and scope frames if available) with the servicemanual.Verify that voltages are within reason and can be set likewise using the trimmers and speed adjustments.Check visually for bad components, burn marks and cracked solder joints.