• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Servicing a SONY DAT machine (Pictorial)

Very interesting to see the interest in these decks. I have a DTC-670 that quit working simply by sitting on a shelf not being used. Yay, Sony. :rolleyes: I'm not sure if I should bother trying to fix it, or get it fixed, since I really have no use for it beyond a couple of rare tapes. Last time I tried to sell it for a decent price, I had the usual Craigslist assclowns offer me $50 or less. Beyond producing no sound (I do not hear the relay clicking on/off as it used to do while playing some of the questionable tapes), it also used to leave some tape dangling outside the shell if it was removed and the tape was not rewound totally to the beginning.

Ten years ago, I may have had the eyesight, dexterity and patience to do it, but not anymore. But since it is already a lost cause, I still could try to get it working again, although I'm not dumping any expensive parts into it.

I really don't like the thing. Or Sony. But on the other hand, it's hard to part with. :D
 
Hi guys,

My DTC-55ES suddenly developed a strange fault in that the pinch roller will engage and touch the capstan axis in FF or REW just like in PLAY MODE, making rewinding or fforwarding very slow (Same issue in track search). :(

Everything else works as it should, the mechanism is aligned by the book so I cannot see why this is happening.

Any ideas as to what might be causing this odd behavior? :idea:

Any advice would be highly appreciated, thank you in advance!
 
What do you mean by "aligned by the book" ?

Did you check the rotary encoder gear ?

Did you clean the inside of the rotary encoder itself ?

Did you set the rotary encoder position according to the service manual ?

Did you clean both loading rings / arms from hardened grease

Does the F guide move freely and return to initial position due to its spring ?
 
Last edited:
Everything you mentioned has been checked/performed, this is what I meant with "by the book".
Rotary encoder opened and cleaned, new loading gears and rotary encoder gear, encoder position set precisely, all mechanism has been de-greased and lubed accordingly including all arms, removed and oiled, F guide moves as it should as does everything else, freely and smoothly.
Any other suggestions maybe?:(
 
I've just made a short video and uploaded it it to demonstrate the problem. It can be seen HERE.
One can see how the pinch roller engages the capstan when pressing FF or REW just as in PLAY MODE.
Everything runs smoothly and all other operations are spot on.
 
Hdrobien, already tried that too, little by little up to almost 30 degrees both ways to the point where in one way the capstan starts spinning clockwise and in the other way the pinch roller does not touch the axis anymore so no improvement altering the encoder's position unfortunately...:no:
 
Last edited:
I just purchased a Sony 670 at a Thrift store- sans remote.
Seems to be in working condition but won't know for certain until I can obtain some DAT tapes and a cleaning cassette.
Just posted this comment as I find this thread to be very interesting ; I never had the opportunity to read about repairing one of these units.
 
Hello guys,
After couple of months I come back to some of my DTC-57 to be repaired.

I have following problem, when I setting up DPG by osciloscop and AMS buttons, deck won't keep value in memory. Any idea where value of dpg is stored?

3V clock battery seems to be Ok.

Thanks
Regards
Roman
 
Hi to everybody!
My little daughter messed up with the controls of my Sony DTC-ZE700E and pressed eject while tape was rewinding. Tape slacked inside, with CAUTION error on display. I have managed to securely eject tape without damaging it, but there are some anomalies as a result. Deck doesn't read time code on any tape, just displaying -:--:-- , even on tape recorded by himself, mechanically everything looks ok. REW, FF works, over head REW/FF also, load/unload tape also, play works, drum is spinning, transport of tape looks normal. Is this azimuth problem now? I don't possess osciloscope, is this problem repairable? Deck worked for years without any problem.
 
Hi

If you press eject while the transport is in operation it should first stop the tape and retract the guides so there must be a problem from the beginning.

Are you sure that both guides extend and retract ?
 
Yes. Both S1 and T1 extend and retract normally. Of course, visually. Maybe a portion of a milimeter matters? Deck now just won't read time code on any track, but I checked, music on the tape still exists.
 
If T1 and S1 are not synchronised they can not extend and retract normally.

Maybe the heads have been damaged. Try to clean them (paper soaked with isopropyl alcohol).
 
Problem solved. S1 and T1 were unalligned because both plastic washers broke and gears which moves guides were out of synchronicity for just one tooth. I disassambled the whole mechanism, cleaned it, put back guides in order. There were many connectors, gears, wires, but I manage to put all together with success. I put little epoxy on top instead of washers, and currently listen music from DAT. Thanks to everybody for support.
 
My DTC-60ES doesn't do anything with the tape when closing the door. Beyond testing/cleaning the cassette present switch, are there any suggestions of what to check? I can hear a motor whirring when I power the deck up, but that is all. I get no errors on screen and the door opens/closes without any problem.
 
You must disassemble it, and observe if tape guides S1 and T1 start to move in its end positions. If not, you do have some mechanical issue. Also, if the guides stands still, most probably motor is out of voltage or dead at all.
 
Guys, especially Sasi and hdrobien, I want to say a HUGE thanks for your detailed info on this forum for helping me fix back a Sony PCM-2700A that i saved from a recording studio and decided to do the repairs myself. The left hand S1 guide was very wobbly and not travelling to its post during playback which resulted in a lot of reading errors etc. I had to dismantle the mechanism and realign the two teethed rings and aligning them so the holes match up.
I also changed the surface mounted caps in the 2 rf blocks and the combiantion of both jobs resurrected this DAT machine. There was nothing else wrong with it (well so far). Just wanted to say a big thanks you for your efforts
 
Gosh, I obtained this (and a 2300 which still needs attention) a few years back and have sat in my loft till this week and decided to check the 2700A out. At first when I tried to play a tape there was no sound. Seeing that the machine was practically thrown out I almost gave up straight away thinking it would be the electronics or even the head. Just for the excercise I decided to first change the 6 smcs that reside in both blocks of the RF amps and replaced them with standard caps. Upon re assambling the unit... I GOT SOUND :). However,it was mostly garbage sound and suspected the heads or possibly a misalignment!. I took patience in fiddling a bit with it by just monitoring the sound and poking gently the S1 guide and suddenly the sound came back, intermittently as the gudie was very loos. I came across this website which is excellent for what I needed and realised that the S1 guide was not actually travelling to the furthest position it should be doing, compared to the other guide. I wasn't sure whether the guides should be so loose or not and at first thought that it got all loose as perhaps a screw underneath was not tightened enough?
Today I decided to dismantle step by step the transport and only thanks to you and Sasi that i did it and you helped with your earlier post regarding a similar machine to mine that uses circular teethed rings, so thanks to you both I went for the kill, stripped the transport down and put it all back making sure that the 3 holes (2 on the rings and one on the chassis) aligned well before carrying on.
It is all working nicely however i suspect it's slightly out of alignment perhaps as the sound is slightly harsh and distorted. I seem to get some drop outs when I play a tape recorded on my Sony DTC-750 (sort of digital noise). I would understand if an alignemnet of both guides is needed.
What I don't know how is how to set my oscilloscope to trigger. I never tried that. I have a Tektronix 453A and have no test tapes, however I do have tapes that were recorded in a studio so can use those I guess.
Would you be so kind as to assist me in how to align the machine perfectly well please to ensure it plays correctly and compatible with other machines? I guesss I will need to connect channel 1 of the scope to RFPB and the other channel to SWP? Which of the two RF blocks will I need to connect the scope to set the guides? I do know what the pattern should look like but if you have any links perhaps you can share that would be wonderful.

Cheers
 
Did you just "realign" the 3 holes or did you also unstuck the silver sliding hook positioned on one of the large teethed rings ? It should slide freely and on almost all units I have serviced it was stuck due to hardened grease.

It is in fact the major issue of this mecha.

Btw never had a problem of bad RF amp capacitors on the 4 DD mecha, only on 670/57ES/690/59ES/60ES.
 
You must log in or register to reply here.
Back
Top Bottom