JVC AV-S33MS6 - help getting inside

[steerpike2]

I've got a JVC AV-S33 (33 inch, about 60kg (130 lbs)) with purity & convergence errors (nothing that the geometry menus in the service mode affect).
I want to open it & check the yoke & degaussing, BUT the cabinet is nasty & plasticky. The two rear feet are part of the cabinet 'back half', so I suspect some weight rests on this.
How is the safest way to get that back cover off, without compromising the cabinet's ridgidity, and having it fall over backwards?
Am I being too cautious, and are they built to have a technician just pull the back off? Wooden cabinets were much easier!

Any tips please?

[bgadow]

I haven't worked on very many newer sets, but every one I have had on the bench was fairly simple-they are balanced so that when the back comes off they won't go anywhere. This is a monster. I just had a 32" Toshiba that I toyed with...it was surprising how little there was to the cabinet considering its heft. But there seemed to be no danger of it all collapsing! Maybe someone will come along with experience of that model.

[steerpike2]

Bryan, you were right - it balances perfectly - there is no weight on the back feet - they must be there as a safety measure in case it's pushed over from the front!
The back came off easy as pie... or is that pi ?

And again, the PCB is quite ridiculous sizewize, in regard to the sets overall size and weight - no bigger than that in a 14" computer monotor.

[andy]

...

[steerpike2]

I has a sony 34" briefly - it came with a special strap/hook attachment that the instructions said must be screwed to the wall or shelf behind the TV, specifically so it wouldn't fall over forwards by accident. Sony ought to buy a book on centres-of-gravity and ridgid body rotation!

Anyway - as for the JVC, its now fully fixed. The deflection yoke had spontaneously inched its way back along the neck of the tube, away from the flare. Odd, as this set hasn't been moved in any way in 10 years. Must be a heat-up/cool-down kind of walk.

[andy]

000

[MRX37]

Originally Posted by andy

I see that a lot. Even if the picture still looks ok, most older sets improve if the yoke is pushed forward.

Also, I've found that the correction magnet strips on the yoke lose strength, leading to bad convergence in the corners. Took me awhile to figure this out.

[freakaftr8]

Let me guess, the rubber yoke strips on the back of the crt fell off and laying on the PCB too? yes I think heat does this.

[steerpike2]

Let me guess, the rubber yoke strips on the back of the crt fell off and laying on the PCB

Actually, no. The only reason I knew this was the problem was I could see a band of 'clean' relatively dust-free rubber and glue where the gap between the tube flare and the deflection yoke had opened up.
The yoke's clamp around the tube neck was still really tight and I had to push quite forcefully to move it, even after losening the screw.

[Yasserbogard]

Hello everyone, I know I'm asking this in a very old thread, but I found the same crt with the same exact model number, but couldn't know what inputs it has? Does it support both ntsc system japanese and usa or only Japanese? Is it a good crt with great picture do you recommend it? Thanks ��

[Electronic M]

Originally Posted by Yasserbogard

Hello everyone, I know I'm asking this in a very old thread, but I found the same crt with the same exact model number, but couldn't know what inputs it has? Does it support both ntsc system japanese and usa or only Japanese? Is it a good crt with great picture do you recommend it? Thanks ��

I haven't seen or owned this model, but I can tell you a little bit about Japanese VS US TV standards in the analog era. Both countries used NTSC. Japanese NTSC set black level slightly different (probably not noticeable, but easily compensated by adjusting brightness) the other difference is that the Japanese VHF broadcast band is reshuffled compared to the American band. In the US broadcast FM radio is between CH6 and 7 and we deleted CH1, but in Japan there is a CH1, and their FM band is below it...So if using an American RF modulator with a Japanese domestic market TV or VCR you need to use CH7 or higher on the modulator and the TV will probably be tuned 1-2 channels off the modulator channel. Wikipedia for NTSC lists channel frequency ranges for US and Japanese VHF TV so you can use that to figure out the offset. I did a few years ago when I bought a Japanese domestic market ED Betamax deck.
Obviously cheap consumer RF modulators only have channel 3 and 4, but professional RF modulators designed for hotel, school, and small public cable TV systems such as those made by Blonder Tongue can do all channels....Some are fixed channel (built for say ch9 and can only do ch9) others are agile (can be tuned and retuned to any channel, or most of the channels). You can find professional modulators used for cheap on eBay and public surplus sites.

Also if you have ever been annoyed that you have to run a wire from your modulator to you TV because consumer modulators don't have enough power to transmit you'll be happy to know that Blonder Tongue AM60 and BAVMz family modulators have enough output power to transmit a block with a tuned dipole antenna.

[zeno]

The set MAY be changed through the service menus BUT you
would need a service manual.
BTW whenever you change anything in menus write down the old settings.

BTW # 2 US sets have to pass a forward tilt test before that model
can be sold.

Zeno
LFOD !

[Yasserbogard]

Thank you all