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4025 Marantz Tape Receiver No Tape Sound

omri617

omri617

Super Member
Hi
Receiver sounds fantastic tuner also works
But tape doesn’t play any sound.
I noticed that VU meters don’t work too.
Are they related to the issue that I get no sound from Tape? Tried with headphones too - no sound from Tape
 

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omri617 said:
But tape doesn’t play any sound.
I noticed that VU meters don’t work too.
Are they related to the issue that I get no sound from Tape? Tried with headphones too - no sound from Tape
Click to expand...
The first thing to do is check to make sure that the tape is actually moving when you press the PLAY button.
  1. Belts could be missing or disintegrated with age
  2. Press PLAY and watch for the capstan spinning, pinch roller moving, and take-up reel hub moving
  3. If not, then check the belts. It looks like there are two of them
  4. Next, if you haven't done so already, clean the tape heads with 99% Isopropyl alcohol. Also, clean the capstan and pinch roller.
  5. As for the VU meters. They will not move if the tape is not playing.
  6. You can try to put it into RECORD and try to record something from the tuner (that works). See if the meters move when you do that.
  7. You should also clean all of the switches and controls with Deoxit.
1789051115918.png1789051061019.png
 
Check to make sure that the tape heads move up to contact the tape when in PLAY and the tape is moving?
Did you check to see if the VU meters move if you put it into RECORD using FM signal source?
What test equipment do you have and are you comfortable using it to check voltages and signals on the Tape Preamp board (PJ00)?
Do you know how to read a schematic?

Here is the Tape Preamp board:
1789082160011.png

Here is the board layout. If you have some equipment to troubleshoot electronics we can proceed, if you have not worked with electronics troubleshooting before then it may be better to take it to a technician.
1789082274708.png
 
dankik said:
Check to make sure that the tape heads move up to contact the tape when in PLAY and the tape is moving?
Did you check to see if the VU meters move if you put it into RECORD using FM signal source?
What test equipment do you have and are you comfortable using it to check voltages and signals on the Tape Preamp board (PJ00)?
Do you know how to read a schematic?

Here is the Tape Preamp board:
View attachment 3834183

Here is the board layout. If you have some equipment to troubleshoot electronics we can proceed, if you have not worked with electronics troubleshooting before then it may be better to take it to a technician.
View attachment 3834184
Click to expand...

dankik said:
Check to make sure that the tape heads move up to contact the tape when in PLAY and the tape is moving?
Did you check to see if the VU meters move if you put it into RECORD using FM signal source?
What test equipment do you have and are you comfortable using it to check voltages and signals on the Tape Preamp board (PJ00)?
Do you know how to read a schematic?

Here is the Tape Preamp board:
View attachment 3834183

Here is the board layout. If you have some equipment to troubleshoot electronics we can proceed, if you have not worked with electronics troubleshooting before then it may be better to take it to a technician.
View attachment 3834184
Click to expand...
Yes I have DMM and a scope and signal generator and I can make my way through testing but I never fixed a tape before so I don’t know where to start
 
Thanks. (Is your scope a digital or analog scope?)

There is a long switch on the PJ00 Tape Pre-Amp board that is mechanically moved when you press the REC button (shaded red).
  • The contacts can get oxidized and need to be cleaned.
  • With power off, spray Contact Cleaner into the ends and any openings on the metal bar so it can get onto the switch contacts.
  • Move the bar back and forth about 40-50 times to work it in. Let it sit overnight, then try a tape to see if there is any improvement.
1789168848019.png
 
Last edited:
OK. I would like you to insert a tape and play it.
  • We will look for the signal on the Tape Preamp board (PJ00).
  • Set up your scope to measure AC signal, auto trigger, 10X probe
  • Clip the ground lead to the metal chassis
  • Attach the scope probe to test point JJ42 (red dot and arrow on the board layout)
  • Play your tape and look for a signal trace... anything?
  • Test point JJ41 is the other channel. Try it also.
  • Let me know what you find.
1789432651462.png
 
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