Transport problem on Pioneer CT-9R

Discussion in 'Tape' started by chindokae, Apr 3, 2018.

  1. chindokae

    chindokae New Member

    Messages:
    5
    I have a CT-9R that I am working on. It has an odd problem with the transport. After replacing the belt I tested it with a tape and found that the pinch rollers don't pinch.

    The head assembly does rise and stay in place, but not quite far enough to let the pinch rollers contact the capstans.

    The upper limit stop is very positive and metallic. No plastic. I can hear that much. Looking down inside the mechanism with the reel motors off, I see a brass pin that engages a slot in the back plate when I push the head assembly up. I don't think it goes any higher than it is going unless that pin is supposed to retract, and there appears to be no way for that to happen. It appears to be coming out of the head assembly and it I can see probably 12 mm of it. It's a pretty hefty pin and there does not seem to be anywhere for it to retract to.

    It looks like the head assembly is just hitting the designed upper limit.

    I know some one has been in there from the misplaced screws. What I am wondering is if the pinch rollers were replaced with ones too small for the deck. Or maybe they shrunk. Normal wear is not a possibility because there is a gap between the capstans and the rollers (both sides) and wear would have stopped with them just in contact.

    Does anyone know what size the pinch rollers are supposed to be? Mine measure about 17.9 mm.

    Any other ideas? I am stumped at the moment.

    Pin with heads down:

    heads_down.JPG

    Pin with heads up:

    heads_up.JPG

    ps: yeah, the endoscope has the wrong date. Those were taken today, 4/4/2018.
     
    Last edited: Apr 3, 2018

     

    Please register to disable this ad.

  2. tapetech

    tapetech Repair Professional

    Is there a number on top of the transport? Reason I ask is because the early CT9 decks had a serious design problem that caused all of them to fail in a short time. It was not a repairable problem. You had to replace the entire transport with a new design. If you have an early CT9 version, you will not be able to repair it. The new re-designed transports can be IDed with the proper number on top. Unfortunately, I don't know the number for the new transport. Google may be able to find it.
     
  3. chindokae

    chindokae New Member

    Messages:
    5
    I've read that, but I don't see any number on top or anywhere else. I have repaired an original one, though, and this one is definitely not the same. Appearances were misleading; that pin was not quite hitting the top. It now looks to me like it was simply misassembled. One or both of the pinch roller arm tensioning springs was blocking the head carrier plate from moving up fully. Oddly, no one before me had been that far into it. In order to get there I had to cut several factory wire ties. I'm not sure how those springs are supposed go on. Unhelpfully, the service manual has no parts breakdown for the transport, not even for belt replacement.

    The only PDF I have found for this deck ends at page 37 in the middle of an alignment procedure. It seems hard to believe that they would have failed to cover belt replacement. It was hardly intuitive. There are probably more than a few missing pages.

    Thanks for the hint.
     
  4. tapetech

    tapetech Repair Professional

    The new, re-designed transports had a number on top. I wouldn't bother trying to fix an original transport if that is what you have. It will be nothing but problems.
     
  5. chindokae

    chindokae New Member

    Messages:
    5
    Thanks again. I had removed the part that carried the marking and it's not the new one, but I had one of these with the original design defect, and this one no longer has it. It was retrofitted with replacement parts so that must have been very early in the game. It's just that whoever *attempted* the retrofit had two left thumbs and an inability to count. Or follow directions. Or the technical capability to notice he had one of the four tape sense arms on incorrectly.

    Nothing in this one appears broken, I think the guy just botched the retrofit in amazing ways. Of the three ball bearings that float the erase head carrier, I removed four. He had somehow managed to cram a fourth one in there. Needless to say it wasn't floating, or even on straight.

    The upside of this is that it appears to have sat around for decades broken and experienced no further wear. There is remarkably little wear on the heads or capstans or pinch rollers.

    In any case, it costs nothing but time to tinker with it, and I find that I really miss doing that. I used to work in a shop that maintained about 200 reel-to-reel recorders that ran 24*7*365. I really enjoyed maintaining them and while this isn't exactly at that scale, it does make me happy.
     
    Last edited: Apr 5, 2018
  6. tapetech

    tapetech Repair Professional

    In the original defective transports, no part is broken or breaks. Several parts were the wrong size and that is why it didn't work. So the fact that you found no broken parts proves nothing. Pioneer did provide a kit to fix the early transports and I installed about 30 of those kits. If you are sure that transport has the kit installed then it may be repairable.
     

     

    Please register to disable this ad.

  7. RIQUE

    RIQUE New Member

    Messages:
    3
    Is there any way of determining if the unit is a ¨new transport¨ vs old looking at the serial numbers of the deck?
     
  8. AudioWizard

    AudioWizard AK Subscriber Subscriber

    Messages:
    111
    Location:
    Reno
    I installed over 100 of those updated transports back when they where under warranty. The transports were complete assy's , heads, wires and all. All of the CT-R's models of that year had problems with transports, there was multiple problems, which is why they replaced the entire transport instead of individual parts. Back in the day under warranty, you replaced individual parts not assy.'s, so this showed that this mechanism was a real problem for Pioneer, to go as far to replace the whole thing. Some problems that I remember ( hell that was a long time ago) 1. The posts that held the erase head and the dummy head would pull out of the die cast mounting plate which is under the R/P head plate. 2. Pioneer used some type of teflon coating on the head rotating assy. The clearances were not right so the head would get stuck in rotation. On your problem be sure that the head is making the rotation all the way to the azimuth screw stops. If I remember, if it doesn't hit the stops then the pinch rollers won't engage all the way. Pioneer lost their ass on those models
     
  9. RIQUE

    RIQUE New Member

    Messages:
    3
    Appreciate your reply Wiz but do you know if any NEW units were produced with the the new transport mechanism. Thus a proper functioning later unit is a possibility?
     
  10. AudioWizard

    AudioWizard AK Subscriber Subscriber

    Messages:
    111
    Location:
    Reno
    I am not sure if any of the later units had the improved transports, you would think so, but it takes awhile for corrections to go through the system. Remember from a service stand point, we only saw decks with problems, there could of been later production runs that were fine. I can't remember if Pioneer issued a service bulletin on affected S/N's range, could something for further research . If a deck came in with any transport problem, we replaced it. Sales side of the dealer, started steering customers away from sales of these units, because they were like a boomerang. They would sell them and service would see them right away, customers where pissed and rightfully so. The electronics side of the CT-R's where ok. Most of the decks where CT-7R, because it was at right price point for most customers and the most popular model, but all the CT-R's of that vintage used a similar designed transport. Another customer complaint that I just remembered is that the tapes would get warm after a long play time, because of the direct drive reel motors right behind the cassette shell. Not to step on any owners of these but, IMHO they where a bad design over all.
     

Share This Page