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Stymied by Nak 480

nakmandan said:
The 480 doesn't have any well illumination. The only lamp that can barely be seen near the well is for the tape motion sensing lamp on the right side of the transport. And the 480 series is not affected by transport function lamps being burned out. I could be wrong on this one but I don't believe the 480 series mutes when a lamp goes out.
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Is there a voltage I might apply to various motors to check for function?

Have you read the entire thread? Do you have any suggestions?
Any measurements I should take?
 
nakmandan said:
The 480 doesn't have any well illumination. The only lamp that can barely be seen near the well is for the tape motion sensing lamp on the right side of the transport. And the 480 series is not affected by transport function lamps being burned out. I could be wrong on this one but I don't believe the 480 series mutes when a lamp goes out.
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I had tried to repair a 480 didn't see any tape motion sensing lamp in there. I am not very good at electronics, but tried my best to repair it. Could you guide me where the lamp is located in there.

My 480 has a broken plastic piston/eject haudralic, which causes the unit to stop after some time when it play's. I need to check again if it is because of the broken parts or lamp.
 
Near the counter. Far right part of transport. Put deck in dark room and you should see a light. A dead bulb if not.
 
radiokom said:
What is wrong with this number? 13 what is included in number? Relax, Japanese are not superstitious, they use Nr.13 even in hotels and planes. And, as we see- in transistor numbering.
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Showing shorted along with the diode when in circuit.

Tests good out.
 
nakmandan said:
The 480 doesn't have any well illumination. The only lamp that can barely be seen near the well is for the tape motion sensing lamp on the right side of the transport. And the 480 series is not affected by transport function lamps being burned out. I could be wrong on this one but I don't believe the 480 series mutes when a lamp goes out.
Click to expand...
Any hints to my issue you can give?
 
See anything out of place here?
 

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You have the transport out. Turn the big white gear with your finger and keep turning until it stops. Headblock should gradually raise as well as pinch roller arms until pinchrollers are locked against capstans. Both reels should spin freely with little resistance. Turn the white gear back to the stop position. Everything should lower smoothly and when at stop position both reels should still turn but with resistance , both brakes should be on.
 
zedex said:
You have the transport out. Turn the big white gear with your finger and keep turning until it stops. Headblock should gradually raise as well as pinch roller arms until pinchrollers are locked against capstans. Both reels should spin freely with little resistance. Turn the white gear back to the stop position. Everything should lower smoothly and when at stop position both reels should still turn but with resistance , both brakes should be on.
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Yeah, ....done all that many times.

I have put voltage to the control motor,....works.

24v at the switches.

Still only rewind.

Pretty sure I have tested every transistor in the deck and they all be transisten.
Checked every diode and they be diodin.
I have a heck of a time trying to balance the switch plate and touch probes while trying to operate,.....much profanity.

You can see in one pick how it is timed at S and how the VR is clocked with the function gear.

Every wire has been checked for continuity.

Thoroughly checked for cold solder joints.

I'm am expecting a face to palm eventually,...but so far I haven't reached the limit of muh stooopidity.

Anybody want to loan me an ohsilly scope and a t-100 analyzer?....lol I'll let ya barry muh toob checka.
 
drumbum said:
Yeah, ....done all that many times.

I have put voltage to the control motor,....works.

24v at the switches.

Still only rewind.

Pretty sure I have tested every transistor in the deck and they all be transisten.
Checked every diode and they be diodin.
I have a heck of a time trying to balance the switch plate and touch probes while trying to operate,.....much profanity.

You can see in one pick how it is timed at S and how the VR is clocked with the function gear.

Every wire has been checked for continuity.

Thoroughly checked for cold solder joints.

I'm am expecting a face to palm eventually,...but so far I haven't reached the limit of muh stooopidity.

Anybody want to loan me an ohsilly scope and a t-100 analyzer?....lol I'll let ya barry muh toob checka.
Click to expand...

Move sensor lamp works?
 
Same as before, I only have rewind function. No play, FFW ect. There are also no illumination of buttons when pressed.
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Can you elaborate on "no play, FF"? So absolutely zero happens when you press those button? No sounds from inside? No motors turn? No lights change status?
 
tapetech said:
Can you elaborate on "no play, FF"? So absolutely zero happens when you press those button? No sounds from inside? No motors turn? No lights change status?
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yeppers,...exactly that.

nothing,....but eye gots backerup gear.

I did discover what seemed to be a shorted transistor and diode in circuit,...but tests good out. Why would that be?

The orange cap disease is referencing the orange chicklets and not the electrolytics,...correct?...odd
 
drumbum said:
yeppers,...exactly that.

nothing,....but eye gots backerup gear.

I did discover what seemed to be a shorted transistor and diode in circuit,...but tests good out. Why would that be?

The orange cap disease is referencing the orange chicklets and not the electrolytics,...correct?...odd
Click to expand...

I believe it is like to practice stomatology or gynecology if you are a cook. You can get a dentist who can consult you by distance, but I doubt your patient will be happy ;)
 
radiokom said:
I believe it is like to practice stomatology or gynecology if you are a cook. You can get a dentist who can consult you by distance, but I doubt your patient will be happy ;)
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I don't think you are trying to help and your humor needs serious work.
 
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