1. Home
  2. Electronics Repair
  3. Bad Video Head on Hi8 Deck?

Bad Video Head on Hi8 Deck?

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 obje cts, 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 lik e this on any video format. Usually I would expect snow, to some degree, ov er 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, an d 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 rec ord. This deck has 6 heads - 2 for SP, 2 for LP, and 2 for flying erase. I sus pect the LP heads are bad - it produces snow over the entire picture in bot h 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.

Reply to
packrat1979
Loading thread data ...

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

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

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

Reply to
jurb6006

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.

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.

Reply to
amdx

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.

Reply to
Cydrome Leader

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.