Bad Video Head on Hi8 Deck?

[packr...@gmail.com]

I have an old, but rather nice Sony EV-S900 Hi8 deck that I would like to use for transferring old tapes. After some very tricky mechanical repairs, it seemed to be playing nicely until I noticed a problem. Very bright objects, such as a sky behind trees, or a sunny window in a room, tend to have random black streaks (looks like static) trailing to the right. The trails are just obvious enough to be annoying. Otherwise the picture is rock-solid, with no snow or other issues.
I'm tempted to suspect a bad head, but I can't recall seeing one fail like this on any video format. Usually I would expect snow, to some degree, over the entire picture. Cleaning the head did not resolve the problem.
I made a test recording with this deck, using a camcorder as a source, and when the tape is played back on another unit (camcorder etc) the picture is perfect. The problem only seems to be occurring during playback, not record.
This deck has 6 heads - 2 for SP, 2 for LP, and 2 for flying erase. I suspect the LP heads are bad - it produces snow over the entire picture in both LP record and playback.
Pausing the tape produces a perfect image, but I suspect that pause mode is only using one of the two heads. I'm wondering if I could swap the A and B heads (by rewiring the board on the upper drum) to rule out or confirm a bad head.
I also checked for bad caps but came up empty. This unit doesn't use any surface-mount electrolytics like the later Sony decks, fortunately.
Any advice would be greatly appreciated.

[jurb...@gmail.com]

Black streaks in the whites is a classic symptom of worn heads. They will record fine at this point I would say but the playback requires a smaller head gap, which is too big because of wear.

It is possible that the LP heads wore faster because they re smaller but there could be a problem in the switching if you get it good in freeze. See freeze does usualy use the smaller LP (or EP in VHS) to pick up a clean field. there are a couple of ways they do it.

Did you ACTUALLY record in LP and havee in not play back on a DIFFERENT machine ?

[amdx]

I made a post about an hour ago, but I don't see it.
Anyway, I have had experience (11,000 VHS repairs) of the little
bar that rubs on the center of the cylinder head motor shaft, can get
dirty or have non contact and cause this problem. I don't know if Sony
uses this on the EV-S900 Hi8 deck or not but it is an easy fix. Just
clean and or adjust.
The little bar is shown in this picture.

> http://i.ytimg.com/vi/46jbW5qJz14/maxresdefault.jpg

Also, my VCR now does almost the same symptom (not regular snow) and
the problem is the RF out connection, I wiggle it and the problem goes
away. One more just push on areas where the head signal is processed,
could be a shield connection in that area.

Mikek

Time flies, those repairs were done between 1984 and 1994!
I stopped when prices hit about $200 for a machine.

[Cydrome Leader]

You have to share some stories of crazy repairs or problems you ran into.

The stupidest problem I saw multiple times was with some sort of Sanyo?
VHS mechanism that required you to drill and cut the chassis apart to get
to the idler. Newer revisions had the cutout in place from the factory so
it could be replaced by a tech. Otherwise you attached magnets, drilled
dozens or so holes and broke out a piece of that diamond stamped metal.

People really liked to spray WD-40 into VCRs when they sqeaked too. Kids
liked to "feed" VCRs as well.

[amdx]

Oh ya, dozens of items found inside the VCRs. We were warranty repair
for Sanyo, but I don't recall that idler problem. I had one great repair
on Fisher (FVH906?) tuner had one bad cap, I just happened to find one
day with freeze mist. Replaced a $1 capacitor instead of a $120 tuner.
Funny how so many porn tapes of all persuasions got stuck in VCRs, and
they never requested them back :-)
I once replaced 12 parts in a VCR before finishing the repair, then was
told it was hit by lightning.
I had a nice situation, supposedly an independent contractor, although
all the work was done in his shop, used his part inventory and manuals,
(large selection of many brands). I worked any hours I wanted, and had a
pretty good shield from the crazy public. Had a 60/40 split until $800
then it went to 50/50.
Once had a complaint the remote didn't work, no problem found,
customer took unit home, set it up and remote didn't work. I went
through a few different things and then recalled an article I recently
read about some light bulbs (fluorescent?) that were overloading the
infrared sensors making the remote unusable. I told the customer to shut
the light off, it worked. I suggested he could make a shield over the
sensor so the light didn't hit it.
I got my start around 1974, with 1/2 inch reel to reel Sony VTRs, AV
3600, and AV3650 with flying erase head! :-)
Then came the top loading RCA with the florescent blueish display.
https://www.youtube.com/watch?v=SAJ94SEVBTw
Then we started with the Sony 3/4" Umatic VCR.
http://www.rewindmuseum.com/umatic.htm
I had several other repair jobs before I got into consumer repair
of VCRs just at the right time, VCRs were just getting popular. The VCR
revolution propelled several retail chains to large growth. ABC
Appliance, Fretters and a third I can't recall the name of. We did
warranty and service contracts for all three. I was crazy busy, one week
after Christmas, I did 124 VCR repairs and billed just over $6,000.
I did great during the Reagan administration!
Got to go, if I think of some other repair stuff I'll post again.
Mikek

[Chuck]

Was the other company Highland Electronics? When they went up against
Best Buy, they took a royal thrashing.

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[amdx]

That's it! Highland was a bigger store in my area. I must have been
out of VCR repair before Best Buy arrived. I never saw one in Lansing
Michigan.
Mikek
Mikek

[Chuck]

I was at Best Buy's headquarters in Minneapolis when Highland entered
the Twin City market. Going head to head against Best Buy was their
downfall even though their stores looked nice, tv ads were ok and
their prices weren't bad. Chuck

[Cydrome Leader]

I love stories like this.

I never figured out how, or why, but I had to fix a bit of stuff with
cracked phenolic PCBs, like somebody dropped their VCR, back when they
were still rather expensive. It may really have been shipping damage that
just took a while to cause a failure. They did have large heavy boards for
a while there too.

"Just stopped working" for a camcorder always meant "dropped". There was
also the ultrasonic cockroach repeller, with cockroaches living inside.

[Cydrome Leader]

They had Highland in Chicago. There was also Fretter and Silo, although I
don't recall if they existed at the same time.