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Hitachi VTS-722A SVHS record problem

 
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mghia



Joined: 06 Mar 2008
Posts: 9
Location: NJ

PostPosted: Wed Mar 12, 2008 3:08 pm    Post subject: Hitachi VTS-722A SVHS record problem Reply with quote

Hello,
After trying to record, during playback, what does a blue screen, perfect audio and some image in FF or RR while in play mode? The image I see has bars of static in front of the image.

After figuring out my remote issue I am was finally able to test the SVHS player I bought cheap off ebay.
It does not record well in EP on SVHS tape. The manual states you can record in EP. Since I still do not have the factory remote, It is stuck in EP as default record mode.

At first I had a blurry screen with black lines darting all over it.
After running a maxwell VP-100 cleannig tape (the one that looks like a tape not a white cloth) The image went to as described.

PLAY BACK of EP or SP tapes are very clear. This has 5 heads.
I took the cover off and note tape streaks/smear between the heads on the drum head. These will not come off even with Xylene.

First i tried with a chamios and 91% iso alcohol to clean the heads by gently holding the cloth to the upper and lower assemembly. I rotated the head CC slowly. Nothing came off on the cloth. It seemed I could only feel one or two of the heads make contact. One was certainly prouder than the rest.


Are the heads just worn away? Nothing broke off when I did this and I have no experience what these should look like?

What other issue could it be.
Someone I know said to try in SP mode but I can not get the unit to record in SP until I find a universal remote with that button.

If the heads are worn for record, is there a way to find out the model and maybe find a replacement head?
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Wed Mar 12, 2008 3:24 pm    Post subject: Reply with quote

Without seeing it, may infact be a worn out head. In general if there is no synch.signal detected from the playback video, the unit will switch to video mute(blue screen). ofcourse dirty video head can also cause that. If you can playback both prerecorded SP & EP, it is NOT a cleaning issue as the same heads are also used for recording.

Any distorted playback video can obviously cause that as well as worn out heads. Again judging by the age of the unit, it is possible to have a head problem.

... can you post a picture of what you see/have?
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mghia



Joined: 06 Mar 2008
Posts: 9
Location: NJ

PostPosted: Wed Mar 12, 2008 4:28 pm    Post subject: Reply with quote

Sure I can send photos. WHat do you want me to shoot? How do I up load them?
I want to be clear that tapes made in EP or SP from other machines Play fine and clear. When I use this unit to record in EP I have good audio, blue screen and visible but static covered video in play with FF or RR button pushed.
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Wed Mar 12, 2008 5:26 pm    Post subject: Reply with quote

here is a quick check ;

when you notice the blue screen , does the counter advance or it only advances when you play/FF? (Basically it tells you whether the CTL head is working or not)
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mghia



Joined: 06 Mar 2008
Posts: 9
Location: NJ

PostPosted: Wed Mar 12, 2008 5:57 pm    Post subject: Reply with quote

Ok made the check. At first I was not sure I could call up the counter. Not sure how I did it but now it is active. In blue screen the counter does move and the word tracking blinks trying to fix it. (I would not expect it would)

So then by your post the control head is working?

Next step? Very Happy
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Wed Mar 12, 2008 6:46 pm    Post subject: Reply with quote

k... Not lookin good ...was hoping that it may be the problem. beginning to sound like either a head amp issue or still may be a wear issue? did you say you tried diff tapes?

better yet, canU play that recording on a different vcr to see how it looks?
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PostPosted: Wed Mar 12, 2008 9:59 pm    Post subject: Reply with quote

Maybe this next test will help trouble shoot.
You asked if I can play it in another machine. Unfortunately I do not have another SVHS. However I tried something. I turned off SVHS and recorded on and SVHS tape as well as VHS tape. I think this unit can record in VHS since there is a button that turns the on screen letters SVHS.

Results. I have a full picture with out the blue screen. The picture is grainy and not crisp. I have recorded better on a VHS just to give you an idea. The picture flickers or jumps every so sleightly from time to time.
Again. this is in EP mode since I do not have a way of switching it until I find a remote that has my codes and tape speed.
and come horizontal black lines the streak off from the black areas.

So maybe this give you any idea that picture is visible if recorded in VHS.

Of course I tried recording in VHS on the SVHS and putting it in the VHS player and that did not work. I did try using the SVHS to record on a VHS and that did lay in my VHS player at the same quality as described above. No blue screen but not the greatest.

Did you still want photos of something and how do I up load them to you?
Thanks again for helping.

If you want to see the manual for this here is the link
https://merchant.satisfusion.com/sf/WarrantyCenter/registration/secure/Hitachi/Manuals/ModelNumberManualLinks.jsp?masterModelOID=SF-990332718-2116&random=1205358850922
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Thu Mar 13, 2008 3:18 am    Post subject: Reply with quote

Ok, so basically SVHS record setting is where you see the problem on a SVHS tape.(As a rule of thumb, you can not make SVHS recording on a VHS tape as the unit can sense the difference between the two cartridges as soon as loaded in the vcr & will automatically disable SVHS recording if VHS detected)

The fact that you can record & playback in VHS mode, there are two possibilities; either there is an electronic problem with SVHS record circuitry OR you may infact have a video head wear issue where it is not putting out enough RF amplitude--thereby creating enough distortion to trigger the video mute--
(this may also explain grainy video w/VHS as it is the same heads are used for both formats). At this point, I'm afraid there isn't much more that can be done over the net.

Any further diagnosis really needs to be done with test equipment or perhaps if you can get a VCR tech to look at it for you.
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mghia



Joined: 06 Mar 2008
Posts: 9
Location: NJ

PostPosted: Tue Mar 18, 2008 8:25 pm    Post subject: Reply with quote

Thanks for the input.
Which is more likely, worn heads? Any way you might know of the part # for a new head and the chance of finding one?
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Wed Mar 19, 2008 2:32 am    Post subject: Reply with quote

sorry, haven't had access to old vcr manuals for some time now.

Can't say for sure on this model but I specifically remember that on a lot of SVHS hitachi's, video head was only available as a drum assembly(upper+lower) which litterally made a lot of them uneconomical to repair even back then.

Seriously doubt if you can find the info or even the part with such an old unit.... Just may have to use it as is & eventually look in to some form of disc or hard drive recording instead.

Wink
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