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A-3440 4-track R2R Issues

Tonoje said:
In the second video (but not in the first one you posted a while back, #13) you are running the tape under the pinch roller. It should be threaded between the roller and the capstan.
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You are right! LOL! It didn’t make any difference on this issue though. Not sure how I didnt see that.
 
Richard P said:
Assuming the "Φ" indicates open circuit then yes, the resistors appear to be bad and need to be replaced . . .
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Zero ohms…no resistance. Can you replace these with modern variable resistors of similar value?…assuming they make them?
 
Zero ohms doesn't necessarily indicate they are bad. Resistors fail open circuit. Can you remove the end wires on the zero ohm side and retest? Were you able to test the reel size switch?
 
Also, the 600 ohm measurement is probably reading the resistance through the motor coils. . . . probably need to remove 1 wire from that and remeasure as well.
 
Richard P said:
Zero ohms doesn't necessarily indicate they are bad. Resistors fail open circuit. Can you remove the end wires on the zero ohm side and retest?
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Reading 0 ohms on those two resistors from one end to the wiper is what is what you should read, according to the schematic, since one end is connected to the wiper to adjust the resistance between the other end and the wiper. See below. You can see the white wire connecting the top terminal to the wiper on one and the yellow wire on the other.

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Richard P said:
Zero ohms doesn't necessarily indicate they are bad. Resistors fail open circuit. Can you remove the end wires on the zero ohm side and retest? Were you able to test the reel size switch?
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I will attempt tomorrow and see what I get. I did clean the reel size switch and it didn’t seem to make any difference. Not sure ifmits immediately obvious that it’s working or not.
 
What I would do is clip a meter on DC volts across D623 and switch from play to FF and see if there is voltage there and in which mode. If there is never any voltage there, then the relay is not being energized and we need to look at the drive transistors and logic circuit.
 
Richard P said:
Also, the 600 ohm measurement is probably reading the resistance through the motor coils. . . . probably need to remove 1 wire from that and remeasure as well.
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Removed all three end wires and retested. You are right. Different readings. See below my new numbers in orange…
 

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dr*audio said:
What I would do is clip a meter on DC volts across D623 and switch from play to FF and see if there is voltage there and in which mode. If there is never any voltage there, then the relay is not being energized and we need to look at the drive transistors and logic circuit.
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Getting a voltage with FF but nothing with play.
 
Navcom said:
Removed all three end wires and retested. You are right. Different readings. See below my new numbers in orange…
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Sorry to butt-in @dr*audio, but for the resistor on the left (R903), I think you need to remove the wires from the wiper also, since you only read 13ohms, then measure the resistance from the ends of the resistor.
 
dankik said:
Reading 0 ohms on those two resistors from one end to the wiper is what is what you should read, according to the schematic, since one end is connected to the wiper to adjust the resistance between the other end and the wiper. See below. You can see the white wire connecting the top terminal to the wiper on one and the yellow wire on the other.

View attachment 3062772
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Where can one get this schematic? I have the service manual but it’s a bad scan and parts of the schematic are cut off.
 
dankik said:
Sorry to butt-in @dr*audio, but for the resistor on the left (R903), I think you need to remove the wires from the wiper also, since you only read 13ohms, then measure the resistance from the ends of the resistor.
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Removed all wires. Here’s the results…
 

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petes'picks said:
Could be simple as it needing some lubrication. There is well know issue with the 2300, 3330, 4300, 6300 and their xx40 cousins with the pinch rollers not snapping firmly and quickly into place, also be sure to lube the motors and do a quick search on proper lubricants for that series of reel players. There are tons of videos on youtube with folks fixing the capstan pivot shaft issue. I will include a link to a video showing how a properly cleaned and lubed pivot point should snap the pinch roller into place if yours is sluggish look at some more videos on how to solve.

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I have the exact same deck, dustcover and all.

For sure, these decks are all electro-mechanical devices, and fairly complex. Know your limitations of what you can do for tests-checks, cleaning-lube-etc, and what you cannot do.
 
Something's not right between these two pictures???
The photo on the left is from @Richard P where he indicates 150ohm, 30ohm, 600ohm (L to R).
Yours on the right is 30ohm, 151ohm, 598ohm (L to R). The values are correct, but the order is not. I thought maybe the order of the 1st two were swapped but if you look at the wire colors, the center one has white & pink wires on both photos. The resistor on the left has yellow wires on both photos???
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Conclusion:
  1. Either @Richard P mislabeled his resistors, or
  2. @Navcom, or someone replaced your resistors in the wrong (reversed) order.
@Richard P, or @markd51 can you re-confirm the values of the 3 wire wound resistors in your photo as 150, 30, and 600... in that order. Thanks.
 
Yes. Resistors look fine. I got the order of the resistors and values from the SM so don't go by that . . . . The photo came from the web.

@Navcom - PM me your email address and i'll send the SM and schematics from HiFiEngine to you.
 
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