New problems with Samsung SV4000 multi-system VHS

the power supply died

which seemed like good advice. Except that I found a used SV4000 on ebay for a few bucks which was described as non-working but which did in fact work fine and has continued to work for a year or so

dots tearing away across the screen horizontally, which I take to mean the heads are dying.

powers up fine now. Except that on insertion of a tape, for some reason (before I try to play) about a foot of tape spews out into the interior of the unit.

the idler wheel please? It doesn't look like an RCA (etc) unit where the idler is obvious. I have the whole other unit for spares now. I do know that one can revive a worn idler with rubbing alcohol to get the rubber to matte again for 6 months or so and that for a longer term repair, the idler tyre can be turned around to present an unworn surface; if we are convinced that this unit has an idler and that this problem is the idler.

older machine to the newer one and is this something which can be done with a minimum of technical knowledge and no instrumentation?

Try rotating the head cylinder with a head cleaning cloth saturated with 99 % isopropyl alcohol pressed against the head cylinder with your finger before trying to change out the head assy. Also check the tension assy. band on the supply reel to see if the cloth pad has fallen off. Chuck

hey thank you for your response but I have a few questions:

Is switching the whole head assembly a difficult procedure? (there doesn't appear to be a YouTube for it!) and doesn't it require some form of alignment with instruments after installation? Or is all that handled by the auto-tracking?

Is there a picture anywhere of the interior on this, - or any similar, - unit which would show me where the fallen off cloth pad is please? (the unit was working fine before the PS blew and has just been sitting on a shelf for a year)

As I have already done the spinning the heads against a static Q-Tip, is rubbing alcohol not strong enough to clean heads properly?

I was told to flip burgers till I could pay for a new one and then carry on, which seemed like good advice. Except that I found a used SV4000 on ebay for a few bucks which was described as non-working but which did in fact work fine and has continued to work for a year or so

This week, the picture started giving wavy vertical lines and flashing white dots tearing away across the screen horizontally, which I take to mean the heads are dying.

So I put its power supply into the otherwise working original SV4000 and it powers up fine now. Except that on insertion of a tape, for some reason (before I try to play) about a foot of tape spews out into the interior of the unit.

Is this the standard idler wheel problem and does anyone know how I identify the idler wheel please? It doesn't look like an RCA (etc) unit where the idler is obvious. I have the whole other unit for spares now. I do know that one can revive a worn idler with rubbing alcohol to get the rubber to matte again for 6 months or so and that for a longer term repair, the idler tyre can be turned around to present an unworn surface; if we are convinced that this unit has an idler and that this problem is the idler.

Or with these symptoms, would I do better trying to move the head drum from the older machine to the newer one and is this something which can be done with a minimum of technical knowledge and no instrumentation?

Find one of those kids plastic microscopes and remove the barrel. Cut back, angled-in to the objective lens so you can lay it against the heads with the barrel nearly vertical, assuming there is a gap somewhere to do so, and visually inspect the heads, one may have a chip out of it or you can see some crud or something sticking to one

some pics of what they look like, it is the gap section that is most critical

Thanks for that but what I need is some indication of where the idler wheel= is in this particular transport. (I didnt see one when I took the cover of= f to switch the power supply). Although quite a lot of tape comes out of th= e cassette when I simpy put it in the unit, the problem might still be with= the idler wheel or indeed as has been suggested, the pad.

There is no serious risk that Samsung manufactured their own transport mech= anism and that it was peculiar to this low-production multi-system machine = is there?

The heads were fine when I last used this machine. Or are you really saying= that this machine is a goner and I should concentrate on getting the other= one working on the basis that heads dont actually fail all that often and = whatever the symptoms, I should just clean them better than I have been doi= ng with rubbing alcohol? (There IS a possibility that the old Recoton (cle= an LOOKING) head cleaner deposited crud on those tiny heads which is now st= opping it from working properly)

Yes, on the old machine which was giving the horizontal flashing white dots= and vertical wavy lines, that is pretty much what they look like, though t= hey do look a bit newer on mine than the ones you show. There is no encrust= ed anything on them. I wonder if moving them with more 91% isoproplyl alcoh= ol would achieve anything or should I concentrate on the other machine whic= h may well work but which spews out tape? I can't see a (felt?) pad anywhe= re on it either. [I have taken some photos but doubt I can post binaries on= this forum]

Interestingly, either I am incompetent or I have identified the idler wheel= . It is in the same place and moves similarly to the one on a normal RCA un= it. There is no rubber tyre on it and the whole thing seems to work with c= ogs/teeth.

vertical wavy lines, that is pretty much what they look like, though they do look a bit newer on mine than the ones you show. There is no encrusted anything on them. I wonder if moving them with more 91% isoproplyl alcohol would achieve anything or should I concentrate on the other machine which may well work but which spews out tape? I can't see a (felt?) pad anywhere on it either. [I have taken some photos but doubt I can post binaries on this forum]

is in the same place and moves similarly to the one on a normal RCA unit. There is no rubber tyre on it and the whole thing seems to work with cogs/teeth.

As a last ditch cleaning effort, a business card pressed against the head assy will unclog very dirty heads. The felt is on a thin tension band which wraps around the supply reel. Chuck

El jueves, 2 de agosto de 2012 00:05:24 UTC+2, Amanda Riphnykhazova escrib= i=F3:

ite dots tearing away across the screen horizontally, which I take to mean= the heads are dying.

tighten the drum static earthing strap, this is a common scenario. It may b= e above or below-deck. usually the heads produce black horizontal tearing t= o the right of the image, and the hi fi audio will crackle well before wear= deteriorates the picture.

-B-