Servicing a SONY DAT machine (Pictorial)

[chickenwatt]

Hi Sasi, I'm fixing a Sony DTC-59es which have a strange problem, when I turn it on everything works fine until 10 min or 15 and it starts to sound jittery and then later mutes.
Other test was I turned on after a day and leave it in stop for the same 10 minutes and does the same in stop or in play mode.
So the problem comes every time after 10 minutes no matter if it is in play or stop, I was suspecting of a crystal frecuency variation by heat but I've no way to test that.
I'm 95% sure is not a mechanical problem, what do you think it is pleaseeeee...help!!!

[rosh1]

hi SaSi
First thanks for a wonderful post, I just discovered it today so I havent gone through it all yet. But since I couldnt wait Im posting a couple of quick questions here: I have a SONY DTC-60ES DAT recorder that i was gifted a few months ago.
It has two problems one of which has only begun in the last few days:
1) The cassette door doesnt stay open, automatically closes ALL the time.
2) I got some brand new Quantegy R120 DAT tapes and tried recording on them last week- but when it plays back the sound is very choppy and i can hear some relays switch on and off. Strangely it plays previously recorded tapes without ANY dropouts. A friend says it ought to be a pinch roller issue but Im puzzled how it could play tapes that were recorded on it but not the new tapes.
I would be grateful for any pointers to what i should look for.
thanks in advance

[hdrobien]

Hi

Concerning issue #1 i would chech the limit switch on the mecanism, located on the right side near the large pulley.

Concerning issue #2 i would try first to clean the heads and then i would suspect the RF amp.

[rosh1]

Hi SaSi
While trawling for potential pinch roller candidates for my DTC-60ES I came across this.
http://www.chsinteractive.co.uk/elec...oller-sony.htm

hope this is useful as i plan to buy a few myself to keep in stock..

Originally Posted by SaSi

Hi,

I definately plan to continue and finish this service turorial. After a week of working with 4 different transports and 3 different decks on the (small) bench, life started getting a little miserable and the project started loosing it's appeal. Plus, I ended up needing some parts - my original donor transport ran out of bits and pieces to transplant.

The transports depicted on this guide are identical to the DTC59ES so the guide is totally relevant to your unit - it actually started on this deck.

From your description of the fault, it looks like the rotating gear that enganges the supply or take up spool on the transport doesn't work properly. This can be caused by dirt in the transport (as the deck is rather old), a weak spooling motor or too much tension in the spooling motor belt.

It might also be caused by a failed attempt to repair something. I've had two cases of such problems and these were the really easy ones to fix. One needed cleaning to remove tons of grease and the other needed replacement of the tape load arm location switch sensors.

In the week that passed since my last post on this, I did a little more work that I keep notes on but didn't post it as it mainly involves myself running in circles mostly.

I have "modified" a transport and removed the breaks and tension pads (that needed replacement). This transport has no breaks, no back tension and was thorougly cleaned and carefully lubed. It should have minimum of friction and tape travel should be nice and easy.

I have found that even this transport struggles to FF/REW a tape. 60 min tapes are ok, but 120min are moaning and 180min tapes struggle and 240min tapes don't make it to the end of tape.

Now, I know what most people write about 90 and 120 meter tapes and DAT machines (they are not compatible), but having 2 professional DAT units use them like a charm and also a couple of fully repaired consumer versions (DTC 670 and DTC55) doing the same, it feels like the concensous is a result of lots of units in bad shape having the same problem.

Anyway, I have just received a small lot of spooling motors at $3.95 each and I am planning to replace the motors on two transports that I cannot find anything else wrong with.

I am also doing some experiments on refitting tension pads where the original ones were reduced to a muddy lot of sticky substance and had to be removed. Without them there is no back tension and I can either over tighten the tension arms and get decent play but no FF/REW or keep them loose and get good FF/REW (too good and the deck stops thinking the tape is ended) but having no back tension it leaves me with playback problems as the tape get's curled off the capstan/pinch roller.

I am also looking for a source for pinch rollers. I am expecting a faulty computer DAT drive that might be a source for parts. The Dutch supplier Warren suggested seems to have everything but at 5 euro for bits and pieces each and 38 euro for a pinch roller, fixing a $20 faulty unit makes no sense.

I will be back in a few days (next week most likely) with some more feedback and progress. Most likely I will document the full stripdown of the transport for cleaning and lubrication. This has fixed 10 decks for me already and it is the hardest cases that were left when I started this thread, so perhaps the problems of these last decks are uncharacteristic of the majority.

[rosh1]

Thanks for the tip, I will have a look at it the moment i reach home.
What should i do with the limit switch- can it be cleaned? And how?
Apologies for the questions- Im a relative newbie to DATs..

I saw some posting here on cleaning heads - whats the best approach?

Merci!

Originally Posted by hdrobien

Hi

Concerning issue #1 i would chech the limit switch on the mecanism, located on the right side near the large pulley.

Concerning issue #2 i would try first to clean the heads and then i would suspect the RF amp.

[hdrobien]

Concerning the switch you can check with a meter that the slider part of the mecanism closes it (or opens it) when the loading tray is fully opened. As far as i remember there are 2 limit switches: one for opening & one for closing.

I believe that the loading tray is supposed to close itself if something blocks it.

The best way to clean the heads will be to use cotton swabs with isopropyl alcohol. BE VERY GENTLE as they are fragile.

[chickenwatt]

To Rosh1:
I had that problem and I solved it by changing the pair of springs in the loading tape compartment for a weaker ones

[rosh1]

Thanks all, I opened the deck and cleaned the limit switches as far as i could see, it had some gluey stuff on it. So the problem seems to have reduced - since now its happening only randomly..

however the dropouts in sound still persist, in spite of very gently cleaning the head.. I noted the pinch roller was extremely shiny..plan to get a new one from the UK, can anything be done about that till then?

Originally Posted by chickenwatt

To Rosh1:
I had that problem and I solved it by changing the pair of springs in the loading tape compartment for a weaker ones

[chickenwatt]

Try to view the heads with a magnifyng glass in order to see if some dirt is seen,,if a hard dirt is there i'd prefer to use a printer paper with a bit of alcohol very glently and without making presure

[hdrobien]

Originally Posted by rosh1

however the dropouts in sound still persist, in spite of very gently cleaning the head.. I noted the pinch roller was extremely shiny..plan to get a new one from the UK, can anything be done about that till then?

You can clean the roller with rubber rejuvenator (same used for printer roller or copy machine).

[hdrobien]

Hi.

A new machine in my collection: the Sony DTC-1000ES.

I am trying to put it back to life.

It powers up, drawer opens, but when I try to play a tape, it loads, the "arms" begin to extend but retracts before reaching position. Then it ejects the tape.

Where to begin ?

Thanks.

[squatski]

Originally Posted by SaSi

When the bridge travels to the left of the picture the arms extend fully. The bridge needs to move freely from left to right and as we try to move it by hand we must not feel any jamming point.

I got to here. Mine looks like this (pic below)
Either I've done something really dumb but the bridge on mine is quite stiff. I dont want to put any force on it. also, are the tape feeders messed up?



Tried to take a real good close up pic I'm not sure my cam is good enough.

On earlier post you mentioned moving the black cog my hand to watch the tapefeeders move. and some point I heard a click sound and I thought That didn't sound good !

It doesn't looks like your picture which is this one:


mine's stiff because something is wrong with the white + black cogs? I can't help but think they're the wrong way because the fake stump tooth on the white cog is obviously there to stop any more movement. I could be wrong though.

[SaSi]

Look closely at your pic. (BTW it's clear and good enough to show the details required).

To the right, the black toothed arm appears to be fully extended (as it should) since the bridge is almost fully to the left.

The white toothed arm appears to be in the retracted position and the tape guide it moves is also retracted. Look better and you will see the the clip that secures it in place isn't there anymore (one of the most common reasons for mechanism failures in these decks). My guess is that for whatever reason the clip became loose, fell off and the arm skipped resting in this awkward position.

Look inside the transport or the pcbs or the bottom of the deck for a small white cylinder/clip. You don't want to lose this. I haven't found any suitable replacement as well (I used the ones from transports with bent guides, faulty heads, etc.

[squatski]

i've looked everywhere and can't find it. to make things worse, this 60ES's case has holes in bottom, big chance of it fallen out, sucked up with the hoover etc
I'll keep looking though. is it really that important? also I can see the same clip on other things? would if I took one off just for this part?

[SaSi]

You can use the clip from another part to secure that arm. In one of the posts I explain that in need, you can remove the clip from one of the two gears above that. They are normally facing upwards while these two arms face downwards - hence need a clip.

You could also experiment with miniature c-clips (if you have). I don't have anything similar and did have enough faulty transports that I could use clips from.