Marantz SD 9000 Compudeck Problem

[Ryan Scruggs]

Hi, all!

I have recently purchased a non-functioning Marantz SD 9000 Compudeck, with the knowledge that the optocouplers would have to be replaced. After following this tutorial exactly (http://www.vintagesilversmith.com/Marantz/SD9000/repair/sd9000_fix.html) and purchasing the optocouplers, belts, and idler tires it mentions, I am still unable to play tapes.

Upon pressing PLAY, the tape heads move into place, but almost immediately retract. I assume that I made an error in replacing the optocouplers, but I cannot figure out where I went wrong. Additionally, when I press PLAY, the left tape spool does not spin, as the electric motor does not engage. This motor does work, because the machine will fast forward and rewind tapes beautifully.

Any help is appreciated, and I can supply photos if necessary!

 

[paul_ral]

Does the solenoid work when you press PLAY? I restored my SD-8020 few years ago I made a thread on AK, same problems with optocouplers, one burnt transistor on PK 21 board, missing parts... long story. Now it works fine

 

[Ryan Scruggs]

The solenoid that moves the tape head into position works, yes. I'm new to the vintage electronic restoration niche, so I'm assuming this is the one that you're speaking of. I have taken the liberty of recording a video on my phone and posting it to YouTube of the problem I'm having, if you'd be so kind as to view it!

 

[paul_ral]

I think optocouplers are good because it works in Rewind or Fast Forward mode. In Play mode the coil stay engaged but motor doesn t start?

 

[paul_ral]

Do you have a schematic diagram? I am sure that REV/FF motor (M0002) works fine and problems came from Play motor (M001) section. Check for 12V at pin 4 from P509 connector, then 12V at pin 7 from P502 and Q514 transistor.

 

[paul_ral]

Also check cassette microswitch function, is visible on your recording.

 

[Ryan Scruggs]

Also check cassette microswitch function, is visible on your recording.

Wow, I'm not sure how I am just now seeing these. Sorry for bothering you on TWO threads! I will check on these things and get back to you. I will need to buy a voltmeter, but once I do that, I will get back to you! Thanks again for your help with all this! Also, is the microswitch the switch that speeds up the capstan motor and fast-forwards the tape a little bit when you insert a tape? If so, this is working perfectly.

 

[Ryan Scruggs]

Also check cassette microswitch function, is visible on your recording.

Also, I'm not sure which schematic you need, so here are all of the ones in the manual I have:
@paul_ral

 

[Morrocotudo]

Hi I just finished replacing the Optocouplers on a SD8000, but no luck. The clock/Counter display blinks even when the main power switch is off and the flywheel motor spins when I load a tape. None of the buttons work (FF, Play, etc.). What are the main symptoms when the Optocouplers are not working? Any input will be greatly appreciated.

 

[Ryan Scruggs]

@paul_ral I've acquired a voltmeter! How do I know which pin is which? I've tested all five pins of P509 on the PK21 board, and none of them read 12V. If I do the same thing to the connector, I get varying voltages:

• purple wire: 18.36V,
• blue/white wire: 10.38V,
• purple/white wire: 18.55V,
• white/grey wire: 1.18V,
• white wire: 10.31V

The pins of P509 read, pin closest to the back of the machine to front:

• 1.51V
• 0V
• 0V
• 0.01V
• 0V

The P502 connector all reads 0V, but 502's pins read, from back to front:

• 17.45V
• 0V
• 11.48V
• 11.48V
• 0.02V
• 0V
• 0V

I also cannot seem to locate the transistor you speak of.

With my limited knowledge of circuitry and schematic reading, I'm going to need you to take the reigns on this one!

Thanks again!

 

[paul_ral]

@Morrocotudo : do you know to set the time? The symptom is: after one or two seconds in any mode, Play, Rewind, or Fast Forward, the deck simply returns to the Stop mode.
@Ryan Scruggs: is not very hard to read a schematic diagram. First of all you need to print the pages you need and stick them together in order to follow the wires. I ll take a look in my SD and make some measurements

 

[Morrocotudo]

@Morrocotudo : do you know to set the time? The symptom is: after one or two seconds in any mode, Play, Rewind, or Fast Forward, the deck simply returns to the Stop mode.
@Ryan Scruggs: is not very hard to read a schematic diagram. First of all you need to print the pages you need and stick them together in order to follow the wires. I ll take a look in my SD and make some measurements

Yes. Turn on the deck. Turn the SELECTOR switch to CLOCK SET using the keypad and punch the number i.e. 1, 2, 5 and if its PM press PM (Orange button from the right) to store the time press and hold for 3 seconds the MEMORY button. you can now switch the SELECTOR button to CLOCK or turn off the deck. At this point the time should be kept stored.

 

[paul_ral]

And it is not stored? You must set time in 12 hour format time.

 

[Morrocotudo]

Its been three weeks since I shared my experiences in my quest to bring back to life an old friend from my high school days: Marantz Compudeck SD8000. So far, I have found discouraging news as I have spoke with a couple experts in vintage electronics here in the south Bay. I am Bay Area resident. First the vital components may not be available if you are seeking key component parts such the microprocessor board, good luck finding it. Unfortunally seems like unless you are an expert on early digital/binary technology the MSD8000 was one of the earliest examples of it. Anyway, I took my chance and sent the deck to a vintage expert in cassette decks, paid $65.00 in exchange for a full diagnosis.

It will take between 4 to 6 weeks to get the answer. I’ll keep you posted.