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 obtained a 4002 ( Type 5523 ). It has three problems. 1).When I press start,the platter starts spinning at 33 RPM and the arm travels all the way to the left with the speed changing to 45 RPM at the correct time. When it gets to the end, it returns to the start without stopping. I can stop the arm using the < > buttons. It does this whether there is a record on the platter or not. The record detector lamp is lit. 2),The arm doesn't drop at all and the solenoid doesn't click at all. I checked the function of the mechanical linkages and they all work smoothly with no old grease. I tested the solenoid coil and it has continuity and a resistance of 9 ohms. I applied power to the solenoid coil and the solenoid functions correctly. 3).The third problem is that the arm doesn't move when it gets out of tangency. I moved the arm over a record and if I push it either left or right the tracking servo doesn't cause any movement. I pulled the control board and don't see any obviously burnt or damaged components. Are there any circuits that are common to all three functions that may be causing these issues ?.
I just obtained a 4002 ( Type 5523 ). It has three problems.
1).When I press start,the platter starts spinning at 33 RPM and the arm travels all the way to the left with the speed changing to 45 RPM at the correct time. When it gets to the end, it returns to the start without stopping. I can stop the arm using the < > buttons. It does this whether there is a record on the platter or not. The record detector lamp is lit.
2),The arm doesn't drop at all and the solenoid doesn't click at all. I checked the function of the mechanical linkages and they all work smoothly with no old grease. I tested the solenoid coil and it has continuity and a resistance of 9 ohms. I applied power to the solenoid coil and the solenoid functions correctly.
3).The third problem is that the arm doesn't move when it gets out of tangency. I moved the arm over a record and if I push it either left or right the tracking servo doesn't cause any movement.
I pulled the control board and don't see any obviously burnt or damaged components.
Are there any circuits that are common to all three functions that may be causing these issues ?.
1, It does not see the record. There can be several causes for this but check the lamp positionin relation to the lens system inside the sensor arm. It should produce a reasonably well definedround spot of light on the record, right under the lens system.Check the signal from the opto sensor, with no record on the platter you should be able tosee the peaks from the dark radial streaks on the platter on a scope.Still no luck, replace the lamp. They degrade with age and use and light output fades.Still no luck, check the electronics related to shaping and amplifying the sensor signal.
2, The Beogram will not allow lowering the tonearm without a record. So back to bullet 1.
3, The tracking drive only works when the tonearm is lowered. So back to bullet 2 and 1.
Martin
Do you have any schematics or diagrams of the type 5523 control board so I can find the points to monitor the output of the opto sensor and locate the parts involved in the detector system. The type 5513 Manual which also says it's for the type 5523 doesn't really have any useful schematics or diagrams.
Martin,
I discovered the the tracking photo resistor bulb OIL2 had a broken lead. Would the open circuit from the broken bulb cause the detector circuit to be inoperative ?. I'm going to replace the bulb with an LED as described in the Condor Audio restoration article. If this would not cause the failure of the detector circuit, would you please advise where to connect the leads from my scope to see if the photo receptor in the detector arm is functioning and which components on the control board I should check/replace if the photo receptor is functioning correctly.
The detector lamp appears to be correctly positioned and produces a reasonably round well defined spot of light on the record right under the detector lens system.
Allan
I never replaced a tracking lamp with a LED and must admit I don't really see the reason but I suggest you ask the expert there. He is an experienced pro and will know much more about this than I.
Like Martin has suggested, you will not get the arm to track unless you can first get it to drop! However if there is a broken lead on the tracker lamp it is clearly not going to do much tracking, when you eventually expect it to. So, order a lamp from Martin, and in the meantime concentrate on getting the arm to drop, then you can worry about tracking! BTW the tracking lamp is generously-rated which is why you generally don't see failures, which IMO means an LED is a little bit OTT.
Hint: check (and this is off the top of my head) C23 or somewhere round that area ;)
BigAlT: Martin, I discovered the the tracking photo resistor bulb OIL2 had a broken lead. Would the open circuit from the broken bulb cause the detector circuit to be inoperative ?. I'm going to replace the bulb with an LED as described in the Condor Audio restoration article. If this would not cause the failure of the detector circuit, would you please advise where to connect the leads from my scope to see if the photo receptor in the detector arm is functioning and which components on the control board I should check/replace if the photo receptor is functioning correctly. The detector lamp appears to be correctly positioned and produces a reasonably round well defined spot of light on the record right under the detector lens system. Allan
Olly