My DCC 951 I got today wont extract the tape once inserted and positioned.
The player just rattles and starts to extract the tape from the left side pinch-roller, but the right side does not start to extract at all. In fact the right pinch-roller doesn’t even start to spin.
Then it just gives a rattling sound from what seems to be one of the motors and stops to extract (leaving the left side tape a bit extracted from the case)
It has the notoriuos cracked drivewheel (wich I have ordered a replecement on DCC Museum) but that alone cannot be the culprit in this case.
Something with the extracting process seems to be faulty.
I have recored a short video of this behaviour and hopefully some of you guys have a clue of what’s going on.
Thank you very much for the guidance to this.
I will check it out.
Do the capstans have separate motors or are they run by the same? Since the left capstan on my unit is spinning but not the right one.
Well, Upon inspection without any cassette in the tray, when I power on the unit both capstans are spinning for 3 seconds.
It looks like it’s just when a cassette is inserted that the right one doesn’t spin as the pinch-roller on the right side doesn’t move at all.
It’s not even moving from it’s resting position and does not travel towards the capstan.
It seems like the problem lies with the part where the pinch-rollers and tonehead are attached, that pushes against the tape when inserted.
Strange though that the left side is working but not the right.
DCC recorders don’t extract the tape like DAT recorders. The tape is supposed to stay in the cassette. The problem is the broken gear as you already discovered.
The capstans are driven by the motor near the rear of the deck, using a belt that goes around the motor and both flywheels at the same time. The spindles are driven by a motor that’s underneath. The broken gear is on the shaft of the spindle motor. There’s a third motor for the tray.
That’s normal: Both capstans rotate whenever the deck is in playback mode, but they rotate in opposite direction. When side A is in use, only the left pinch roller (as seen from the front of the recorder) is pushed towards the side A capstan; when side B is in use, only the right pinch roller is pushed towards the capstan.
By the way, besides the gear on the spindle motor, you should probably inspect the pinch rollers. They should be even (no cracks or holes or bubbles) and they should be dull, not shiny. If not, you will have trouble playing and recording tapes. You may want to order a set of pinch rollers from the DCC Museum as well as the gear.
I think this is normal. But the deck detects that there’s no cassette in the tray and it behaves different from when there is one.
Both capstans should spin at the same time; they’re driven by a belt. Only one pinch roller engages at a time so yes, at least one pinch roller doesn’t move, no matter what state the deck is in.
The gear teeth around the crack look so far apart that they might not mesh with the idler gear. You didn’t show the idler gear in the photo; I hope it’s okay.
The spindle motor is supposed to pull the tape taut while it’s being played or recorded. Your deck is spilling tape, which means the spindle probably isn’t turning. That’s probably also why the deck shuts off (or does an auto-reverse) when you hit Play: There’s a sensor on each spindle that the deck controller uses to detect whether the tape is running. If not, it knows that it’s at the end of the tape or there’s something wrong with the mechanism, so it stops the deck.
Wow, thank you so much for this extensive answer.
I think the idler gear you refer to is ok. (see pic)
But the pinch-rollers… Oh Lord…
They are a total disaster!
I have placed an order of new belts, pinch-rollers and gear for both of my players from the DCC museum as of now.
Huge thanks for taking your time answering.
I found the chinese 951 “easy version” of removing the pinch-rollers here on the forum (thank you for posting that) and removed the old ones and tried to clean it the best I could.
It looks like the capstans are somewhat damaged but as I’m a noob I cannot tell if this is normal wear or if they are indeed damaged. What looks like dirt won’t come off when rubbing with IPA on a Q-tip.
And if someone could tell me if the head looks ok or not I would be grateful.
What are those two vertical purple bands on each side?
They look assymetrical to one another.
Yes those pinch rollers will need to be replaced. They might work but you’ll probably get a lot of drop-outs.
The capstans: Well, that looks like they’re just rusty. It is what it is. My 730s also have rusty capstans but they work fine. It might be possible to clean it off but frankly I wouldn’t know how, if IPA doesn’t work. Chances are if you try anything aggressive enough to take care of the rust (like sandpaper), it’s probably also aggressive enough to take the chrome off. You might want to try with a piece of paper: Paper is a little bit abrasive but doesn’t really do damage; some people use envelopes to clean video heads in a VCR and that seems to work quite well. I’d say leave the capstans as they are, and hope for the best. Since they rotate pretty fast and the rust is probably not very thick, the electronics can probably compensate for the small variations in speed…
The head looks fine, although perhaps a bit dirty. The important thing to watch for is that there’s no dirt on the dark part in the center and on the two columns on the outside of the head assembly. those are the parts that guide the tape. Use IPA to clean it if necessary. Always go from top to bottom when you wipe it. Never use a demagnetizer of course; DCC heads don’t need demagnetizing and if you use one, you’ll induce so much current that you’ll fry it, and that will certainly be the end of the recorder.
The two purple bands are just reflection of the light, I think. It’s kind of hard to see and I know DCC heads are hard to take pictures of.
When replacing the capstan-belt you have to remove both capstan-covers.
Videos showing that you have to pry them off and risking to break the plastic locking pins.
But someone wrote that you could press a small philips screwdriver in two holes on the capstan-covers and then the cover will release.
Is that the preferred way of doing it?
The picture on top really looks like that capstan is just dirty and can be cleaned. You can probably use your fingernail to scrape that crud off. The second picture however… that looks like rust from where I’m sitting.
I can’t answer that one. I never replaced the belts on my 730s and they work fine.
If you’re worried about breaking the locking pins, I’d say keep the old belt as long as it works.
In my opinion the 730 has the same mechanics as the 951 and they are interchangeable. But DCC300 and 600 are known for their brittle plastic covers that break easily.
So it’s easy to replace the belt. Just remove the screws of the metal plate that covers the flywheels. Watch the cables when replacing the metal cover. They should not touch the belt.
The capstans can be cleaned with a cotton towel with some polish or Commandant on it. Don’t use to much, and prevent any fluid from entering the capstan bearings. I wouldn’t use sandpaper.
If the dirt or rust cannot be removed, try again with a small peace of wood. When powering on, the capstans will spin for three seconds. Power off and on, and so on. It might be easier to clean the capstans that way.
For what it’s worth, there is another topic about this on the forum. But on the lead and take-up spool there are sensors that are looking at the movement of the spools… if these or one of them are inoperative will give you your troubles…
So look for wheels that are checkered black and silver! There is a infrared transmitter/receiver unit around them. If they do not line up, there is your problem. Watch out for cracks, reglue if possible…