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Servicing a SONY DAT machine (Pictorial)

Hi

I am not home but is the fading function working properly ?

And how long is the fading time ?

Maybe the indicator is blinking because the duration is set to minimum/maximum.
 
hdrobien said:
Hi

I am not home but is the fading function working properly ?

And how long is the fading time ?

Maybe the indicator is blinking because the duration is set to minimum/maximum.
Click to expand...
Yes, fade in and fade out are working properly.

Fade in and fade out times are both 5 seconds.

A real head scratcher.....
 
hdrobien said:
Could you locate the XTEST test point on the main board and check the continuity with ground ? (Power off)
Click to expand...
Any help locating the XTEST test point would be appreciated. I will dig the unit out of my stack tonight and see what I can find. Never done this before.
 
Again here I'm asking for help in this thread. I bought a second DTC-59ES for spares, and to compare with my first DTC-59ES. I did the usual, cleaning the mech, removing old grease, etc (that's why it was sold as non-working), and changed the caps on the RF Amp. But it has the same symptoms as my previous 59ES. I can align the mech on my DTC-60ES, but once I install it on both 59ES, sound distorts every few seconds. I checked with the oscilloscope and PBRF signal looks ok, but it "shrinks" when sound distorts.

Any hints? I think if I find the problem, both 59ES can be fixed.
 
hdrobien said:
Check power supply outputs.

Did you replace C907 ? (6800 µF / 25V)
Click to expand...
Hi, I replaced that cap on my earlier 59ES, but on this one not yet (but I'll replace it anyway).

One question, what should I check with the power supply? I should check voltages (multimeter) or the signal? (oscilloscope)

Thanks again @hdrobien
 
@hdrobien, I checked my first 59ES and in the +10 volts I see 0.3 volts AC (I’m just a hobbyist, this is ripple current?). In the other DC pins I didn’t see any AC voltages. By the way, in this deck I changed the 6800uf cap, and I noticed that some of them have different voltage rating compared to the service manual, for example the board has 63V caps but the manual says 50V (and I have those). Should I be worried?

My newer 59ES just stopped working, it loads the tape but immediately retracts the arms and enters caution mode.
 
The 10V DC is non regulated, so I guess that 0,3V AC ripple is no problem.

The 6800µV cap "supports" around 12V, so 25V is more that enough. If you have caps with higher values, no problem.

If the guides retract with caution mode, there should be a problem with the heads. Do they rotate ?
 
hdrobien said:
The 10V DC is non regulated, so I guess that 0,3V AC ripple is no problem.

The 6800µV cap "supports" around 12V, so 25V is more that enough. If you have caps with higher values, no problem.

If the guides retract with caution mode, there should be a problem with the heads. Do they rotate ?
Click to expand...

Thanks @hdrobien, deck 1 (the older 59ES) plays fine, but from time to time it starts playing digital noise every +/- 10 seconds, but after it warms up. My issue with caps is with 1000uf ones, on the board they are 63V, but on the service manual they are listed as 50V. I think I'll need other caps if I decide to replace them. What do you think, should I replace all the caps on the power board? Currently only the 6800uf is new.

Deck 2, the newer one, is the one that doesn't play now (it was working last week). It retracts the arms and the drum rotates. When it was working, it showed a similar behaviour as deck 1.
 
I believe you can use 35V capacitors as I don't see any voltages above 25V. You can replace everything but I don't think it worth the effort unless there are traces of leak.

On deck 1, check solders on connectors, especially those of the main board (CN501).

On deck 2, something is not responding as it should, so check:
- both end switches located on the Cam Slider Board
- that the gears that drive the guides, rotate freely (4 gears: 2 black, 2 white).
 
digitalfever said:
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!
Click to expand...
Hello.
How did you solved the problem? My DTC-55ES does the same thing.
 
Hi

Could it be a slightly misaligned rotary encoder ? (considering its inner contacts are clean).

From my experience, the best setting is not when the pinchroller is "surfacing" the capstan housing when seen from above in standby mode (according to the service manual), but a little further away.
 
hdrobien said:
Hi

Could it be a slightly misaligned rotary encoder ? (considering its inner contacts are clean).

From my experience, the best setting is not when the pinchroller is "surfacing" the capstan housing when seen from above in standby mode (according to the service manual), but a little further away.
Click to expand...
Thank you @hdrobien
I tried from 1mm to 5mm distance away. At over 5mm there is not enough pinch roller pressure to engage the tape. So I guess the sweetspot is 1 to 3mm.
Anyway, in any situation the pinch roller stays engaged during painfuly slow FF and RW.
The encoder contacts are clean. Opened and checked them twice by now.
I'm out of ideas :(
 
Have you cleaned the 2 large black gears that move the S1 and T1 guides ?

Can the "silver hook" slide freely against one ? (considering its spring, of course)
 
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