Sony SLV-780 Resurrecting The Beast

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Got all these old tapes we made. Not much on TV these days, new shows are a
ll cops and robbers or murders, or surreal movies or really terrible sitcom
 reruns, very few of which were any good in the first place. Plus I got too
 much time on my hands.  

Sometimes it works, then not. Displays a bunch of error codes and I am havi
ng trouble finding out what they mean. It has L 07 11, L15 60, L 18 11, L 0
0 11.

If it ejects it seems fine, until it doesn't. Then after while it ejects an
d then is OK, but if plugged in with a tape in it, it is really uncooperati
ve.  

The 11 code on the end has something to do with the eject not being complet
e. Couple of other codes have to do with not being able to tell what mode i
t is in or something.  

So I am thinking mode switch which is the colloquial term used by VCR tech  
for the mechanical state switch. However I am having trouble figuring out h
ow to get it out to clean it. I already resoldered the connector to it on t
he board, no good. It worked a few times and then threw up an error code, n
ot sure which, it seems to like to throw about 4 different ones at random.
  

Right now there is a tape in it so it will probably not work until tomorrow
, and that is where it does not sound like a mode switch. I've never heard  
of a switch going thermal.  

This sounds like something that was in a service bulletin from Sony a long  
time ago, I got 2 with this problem. The other is a 740 but inside they are
 identical. The 740 is a sacrificial goat because it has other problems and
 some corrosion from being in a bad environment.

Anyone remember working on these things ? Actually I was out of it when the
y came out and working on bigscreens mostly, so when they were newer I neve
r worked on one.  

Any ideas appreciated. I want to watch my old tapes !

Re: Sony SLV-780 Resurrecting The Beast
On Sunday, February 11, 2018 at 1:26:02 AM UTC-8, snipped-for-privacy@gmail.com wrote:
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 all cops and robbers or murders, or surreal movies or really terrible sitc
om reruns, very few of which were any good in the first place. Plus I got t
oo much time on my hands.  
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ving trouble finding out what they mean. It has L 07 11, L15 60, L 18 11, L
 00 11.
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and then is OK, but if plugged in with a tape in it, it is really uncoopera
tive.  
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ete. Couple of other codes have to do with not being able to tell what mode
 it is in or something.  
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h for the mechanical state switch. However I am having trouble figuring out
 how to get it out to clean it. I already resoldered the connector to it on
 the board, no good. It worked a few times and then threw up an error code,
 not sure which, it seems to like to throw about 4 different ones at random
.  
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ow, and that is where it does not sound like a mode switch. I've never hear
d of a switch going thermal.  
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g time ago, I got 2 with this problem. The other is a 740 but inside they a
re identical. The 740 is a sacrificial goat because it has other problems a
nd some corrosion from being in a bad environment.
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hey came out and working on bigscreens mostly, so when they were newer I ne
ver worked on one.  
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Sony is notorious for using really bad lubricants that turn into mud. Many  
problems in VCRs (including broadcast machines) can be restored by cleaning
 out the krud and re lubing.  



Re: Sony SLV-780 Resurrecting The Beast
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Not this time. Everything moves smoothly.  

Re: Sony SLV-780 Resurrecting The Beast
Though I do have a 920 around that I will not plug in because they are know
n for tearing up the rack gear that moves the arm that pulls the tare aroun
d the pinch roller. That needs to addressed eventually when it goes back in
to service. but this 780 is a totally different deck, called an H mechanism
. It is newer. And all the grease looks good.  

I am convinced the problem is not mechanical.

Re: Sony SLV-780 Resurrecting The Beast
On 11/02/2018 09:25, snipped-for-privacy@gmail.com wrote:
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The first thing to do is replace any rubber drive bands, especially on  
loading/eject cycle and mode switch.
Check the plastic pinion on the mode switch drive motor spindle
  is not cracked , due to temp changes and steel/plastic expansion probs

Re: Sony SLV-780 Resurrecting The Beast
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ading/eject cycle and mode switch."

There is only one belt from the capstan motor to the idler assembly and it  
is a toothed belt. There is also a tensioner and it isn't even stretched. A
nd there are no switches on the loading mech.

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is not cracked , due to temp changes and steel/plastic expansion probs"

Looks good, there are no cracks.

This thing is something, the way it detects a tape I have determined is wit
h the record prevent switch and the end sensors. There literally isn't anyt
hing else. When there is no tape in the machine the record prevent switch i
s not allowing record. The micro knows this because whenever there is a tap
e  in it art least one end sensor is covered. If neither is covered and it  
is not allowed to record it knows there is no tape in it. When you push a t
ape in the linkage allows the switch to go to allow record and it runs the  
motor and draws it in. At that point, determined by the position of the mod
e switch it knows if the record prevent is really on or off on this tape. I
f off it loads further and pulls the tape around the pinch roller and acros
s the ACE head for the linear time counter. If on it proceeds that little b
it more into play as most machines do.  

It uses the same motor for everything except the capstan and reels. There a
re no switches on the loading mech. Pretty nifty how they do that eh ? This
 is an H deck and the first one of its kind I have ever worked on. And I go
t some bits and pieces of manuals, and of the one that seems to be complete
 as well as the one for the deck only, neither one shows the "setting condi
tion" where the little marks on the gears go when you recomombobulate it. Y
ou have to figure it out for yourself I guess. I got it mostly figured out,
 at the expense of some time. Took a few hours, in the old days it would ha
ve been minutes. My spatial and 3D reasoning was better, and Icould see. No
w Ihave to do everything with almost no depth perception. Sometime Ithink I
 am tinning a wire ad I fid outI and burning my hand or something.  

I have determined that the problem is not in the deck itself, it is in the  
mode switch connection to the board, or an end sensor, or something on the  
board in the system control.  

A couple of the error code mean it can't figure out what position it is in,
 which means mode switch or end sensor(s). Once I rule out the end sensor(s
), if one of them is not the problem, then I guess I have to follow the con
nections from the mode switch all the way to the processor.  

The processor may actually be bad, the thing works a few times and then act
s up. If it is going thermal I can try some spray solvent to cool it off an
d see if it starts working again. I would bet my left nut that it is no lon
ger available, so if that is the case i will try some sort of heat sinking,
 like with that thermally conductive glue used on other surface mount chips
. Though I haven't seen it yet, it is a good bet that it is surface mount.
  

If it doesn't work I will have to dig up that old 920 and see if I can make
 that work. I won't even plug it in until the lube on the arm is redone bec
ause they are notorious for tearing up that big long rack gear, and I bet t
hat is pure unobtainium.  

the micro should be the same in many models, I might be able to scare up a  
used one, but I don't have the proper tools to change it.  

Six of one, half a dozen of the other. Damned if you do.

Re: Sony SLV-780 Resurrecting The Beast
I got the manual for the 690 or something. The mech is the same but the board is not. I am pretty sure it is an electronic problem at this point. The IC that handles this is IC 501 on the print and IC 201 on the board.  

Any ideas at all on where to get the print for this particular board, or possibly an equivalent model ? System control is all I need, everything else seems to be fine.  

Re: Sony SLV-780 Resurrecting The Beast
On 24/02/2018 04:29, snipped-for-privacy@gmail.com wrote:
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All the years repairing VCRs, perhaps 200 units or so, I think only 2  
were electronics problems, 1 a CCD display driver chip problem, and  
another a large BGA chip problem that needed a push.
Are there indexing marks/arrows etc in the mechanism , in case its  
jumped a tooth?

Re: Sony SLV-780 Resurrecting The Beast
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jumped a tooth? "

There are some. You have to figure it out though because in the manual ther
e is no picture depicting "Setting condition" which shows you how to put it
 for reassembly. I got it pretty much figured out because I have a guinea p
ig, another VCR that is nearly identical. The goat...

I took the goat apart and found that the mode switch is full of nice grease
 and it is not even dirty, and it was treated much worse than the deck I wa
nt to fix. All the grease is good, and mind you this 780 works sometimes, i
t's just that after it warms up and/or goes through a few cycles it does th
is shit, and displays a bunch of different errors, most of which come back  
to either it cannot tell what state the mech is in or the unloading is inco
mplete. I have tested the mode switch with an ohmmeter and it is either a d
ead short or open depending on the position and which terminals you check.  
When it works it does not try to overrun the loading motor or anything of t
he sort.  

The fact that it works sometimes leads me to believe the mech is fine. I st
arted to try to trace the mode switch connections back to the IC but the do
uble sided (or more) PC board makes that impossible. In fact it is more tha
n two layers because the traces from the mode switch go to vias and then on
 the other side is solid copper, a ground obviously. there must be at least
 one more layer in between.  

The print depicts IC 501 and on the board is IC 201. That is where the diff
erence starts. The board.  

I probably posted prematurely, I was going to somehow check the end sensors
 because they are involved in the loading process. But last night I decided
 to putz around with it and find the place where the mode switch actually g
ets to the IC. I'll need to test it on the actual deck I am fixing because  
the goat is all apart, and I found out that little plastic things break whe
n you remove the mode switch. So I am treading lightly because I know most  
of theparts are unobtainium. And if it is the IC, not only do I not have th
e proper equipment to change it, I don't have it to get the replacement out
 of the goat, and plus it has the same problem,or at least it was found in  
the same state, tape stuck etc.  

I might have to just say fukit and fix the 920, now that one IS dried greas
e. I have not worked on one but I am familiar enough to know the the grease
 on the one tape arm dries up and it strips the rack gear. Yes, one of thos
e. So I intend to address that before even plugging it in. I got LPS2 which
 is so good it will do it without disassembly, but I would rather do it rig
ht, get all that goop out. The grease in the 740 (the goat for the 780) is  
in such good shape maybe I should use that.  


Re: Sony SLV-780 Resurrecting The Beast
Printed circuit boards are always composed of layer pairs. So there must be at least *two* layers in between.

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Re: Sony SLV-780 Resurrecting The Beast
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Wonderful.  

I remember the days when I could look at the PC and actually draw a schematic of the circuit. Usually I could just "see" the circuit in my mind but some were a bit more complex so I had to draw it out.  

It actually got easier when they started designing the more modern, rather than hand drawn. I could count the foils "from the big one" and add and subtract as needed.  

It actually got easier than following the old point to point circuits which I used to do well. But now I am a bit lost. I find the old Tektronix type ceramic bindings a bit easier to follow, but not much. I guess I am just losing it.  

I actually could follow a two sided board until everything got too small. I had good spatial reasoning and could turn the board, or me, to see the other side and lock my eyes to the point where I wanted to see.  

Re: Sony SLV-780 Resurrecting The Beast
On 2/24/18 9:33 AM, snipped-for-privacy@gmail.com wrote:
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We've noticed.

--  
"I am a river to my people."
Jeff-1.0
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Re: Sony SLV-780 Resurrecting The Beast
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Hardy har har. Got any ideas on this VCR?  

Re: Sony SLV-780 Resurrecting The Beast
On 2/24/18 5:26 PM, snipped-for-privacy@gmail.com wrote:
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Yeah. A dumpster comes to mind.


--  
"I am a river to my people."
Jeff-1.0
We've slightly trimmed the long signature. Click to see the full one.
Re: Sony SLV-780 Resurrecting The Beast
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I have many reasons to not toss this. Namely old tapes. It is about like new save for this one issue.  

If you are the type who just throws shit out you are part of the problem. You can at least give it away on Craigslist or Freecycle, and on the latter someone might trade you something for it.

Our landfills are filling up at an alarming rate, and tons of money going to China et al to build everything for us.  

Re: Sony SLV-780 Resurrecting The Beast
On 2/26/18 12:22 PM, snipped-for-privacy@gmail.com wrote:
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I thought you said you had one just like it?

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Not hardly. I have a 5000 sq ft shop full of "Shit with wires."
Only the truly deserving get a one way trip to the dumpster.




--  
"I am a river to my people."
Jeff-1.0
We've slightly trimmed the long signature. Click to see the full one.
Re: Sony SLV-780 Resurrecting The Beast
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I have, I think a 720 which uses the same mech and chipset. With the lack o
f information it is a learning tool, iused it to figure out a few things, l
ike using only the record prevent switch and end sensors for the front load
ing mech. Nifty way they didit actually. Saved components and cost but stil
l works. Wellit did.

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Only the truly deserving get a one way trip to the dumpster. "

My yard was 3,500 sq ft. It wasn't all that nice and I abused it. The junk  
I had would have overloaded the dumpster for years. I had a junk room that  
got so full the (wood) floor broke through. What did I do ? I put more junk
 in it. the building wasn't long for this world anyway.  

But I do not deem high end VCRs worthy of a trip to the dump. Some people s
till like them, use them, and others fix them.  

What I need is a beta rewinder. I shit you not. I have an SLHFR60 and HFP10
0 hifi adapter and ;lots of old tapes, some of them camcorder tapes with me
mories on them. Same with the VHS.  

More on it in my reply to Terry.

Re: Sony SLV-780 Resurrecting The Beast
Don't you find watching old tapes on a modern TV painful?

I've gone down that route, and the picture quality stinks, even with very good equipment. Unless the screen is small, and even then.....

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Re: Sony SLV-780 Resurrecting The Beast
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I find new shows and movies much worse. They switch the video so much so fa
st that you can't see anything. Flashing on the screen - ifit was red and b
lue you would think you sre getting stopped by the cops. Thoroughly annoyin
g, as if some little kid is working the board. Not to mention effects that  
almost make you think your TV is malfunctioning. And they can't seem to get
 the picture size and aspect ratio right on some channels.  Plus there is n
o creativity anymore. Simply unwatchable.  

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 good equipment. Unless the screen is small, and even then..... "

The picture quality was fine for most of my life. On my projo KPR36XBR the  
display from the  Sony SLV920HF had the smallest test I ever saw on a stand
ard NTSC TV. On that set  it was sharp and clear. I had aligned the COMB fi
lter to perfection. The convergence was perfect. It was actually better tha
n a direct view. Even though the screen pitch of the lenticular wasn't that
 fine, each section reproduced all colors in the exact same space, a color  
CRT can't do that. In the stores they had these things right next to the di
rect views and they looked as good except for the vertical viewing angle. T
he horizontal viewing angle was about 170 degrees or something like that. T
he small text was broken up on a direct view, my projo reproduced it perfec
tly, and that is without even an SVHS (Y/C) input.  

The Sony VHS video performance is superb, for standard HQ VHS it is only su
rpassed by beta. Of course later formats were better, higher frequency vide
o carriers on the tape, less white clipping and compression, and a few othe
r things. With only SVHS it  only went through COMB filter instead of 3. No
w that I am more used to the Y/C input I am even more sensitive to a poor C
OMB filter.  

But the quality is actually fine. I don't even have an HDTV anyway, and don
't really want one. I can't see much difference unless it is very large scr
een anyway. My sister has an HDTV in the upstairs apartment, I can always w
atch that but I don't see enough difference to make it worth it. Maybe she  
does because she has better eyesight.  

I remember fixing VCRs, I did alot of them. On soem I had to call the custo
mer and give them the bad news that fixing theirs would cost almost what a  
new one would be. Some of them OKed the job, why ?  

For one they finally learned to work the timer. Those were the days when yo
u could use that, now you have to rent a DVR to effectively record or you a
re stuck to one channel until you physically go and change it. That would h
ave been nice when there were good programs on. Now it is hard to find anyt
hing worth watching. Back then though sometimes there were multiple things  
on at the same time. With multiple VCRs and raw cable you could do it, and  
not worry about losing everything in a crash. You had the physical tape out
 of the machine.  

It wore out, sometimes the machine would damage them, they had their drawba
cks, but for what I want they fit. I also have a turntable that plays 78s.  
A Dual 1216, a decent quality one. I bet you would have to go at least a mi
le to find another one who can play a 78. And I can transfer it to the PC a
nd burn it to a CD. I don't really play 78s, but I do play some vinyl once  
in a while. And on audio forums (fora ?) there are people who have $ 10,000
 turntables, soem even more. It does have a certain quality to it, though t
hat might not be so objective. However there is onre thing, the frequency r
esponse does not drop like a rock right at 20 KHz, it rolls off smoothly. S
ome people may be able to hear the difference. In fact I was reading that s
ome people can actually see light wavelengths that others can't. Into the U
V or IR or whatever. They might be the people with superior night vision. M
y buddy is like that. We were walking out in the stix and he had no problem
, I was practically blind.  

My ex-boss could see the numbers on planes in flight. Later though he neede
d reading glasses. He was a licensed pilot, something I would have loved to
 do but I was born with bad eyes. I was about to join the air force like my
 Father and Uncle but found out that I was not likely to ever fly because I
 needed glasses.  

Last but not least, most of what I watch was originally recorded in standar
d NTSC. There is no way to get back the lost quality of that system. There  
is only one system worse in the world, the old one they used in the USSR. E
very other country in the world either has NTSC, and many have something be
tter. Well had, with digital that is all out the window.  

Everything I own is over 10 years old except my PCs and printer, and they a
re getting close. And I like it.

Re: Sony SLV-780 Resurrecting The Beast
On 2/27/18 8:45 PM, snipped-for-privacy@gmail.com wrote:
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Easy enough, I got a Technics SL-2000 all it took was a
simple change to the direct drive feed back. Instant 78
RPM, then a Shure M78 cartridge.



--  
"I am a river to my people."
Jeff-1.0
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