Sylvania 27" tv Brightness Flickers

The "Flyback to cathode wire"!? Jeez.....

No it is caused by the brightness to darkness tube failing.

Sorry. I couldn't remember what it is called. EXCUSE ME for not beign an expert I don't do this for a job.

I was talking about the HV wire going to the CRT. (cathode ray tube) I describet quite well what I was talking about. The wire does run from the flyback to the Cathode (CRT)... "Just Another Theremin Fan" <

Hi...

Just so this doesn't happen again, AND so I can lecture you just a tiny bit...

Yep, CRT is cathode ray tube. The cathode is one of the elements in a cathode ray tube. (cathode ray = a ray [stream?] of electrons flying off a heated cathode)

All of the connections to a cathode ray tube save one are connected via the neck of the tube.

The one exception is the one you speak of, most generally recognized as the second anode.

Hope that helps, now here's the lecture :)

Seeing you admitted to "not doing this for a job" - that connection is lethal. It's lethal whether turned on or turned off, whether plugged into the wall socket or not. It's even lethal after being discharged and sitting for a short while (or a long while)

Be careful of it!!!!

Take care.

Ken

"Michael Kennedy" bravely wrote to "All" (06 Oct 05 23:52:12) --- on the heady topic of "Sylvania 27" tv Brightness Flickers"

MK> From: "Michael Kennedy" MK> Xref: core-easynews sci.electronics.repair:344333

MK> I have a 1987 27" Sylvania tv and it had some cold solder joints which MK> I fixed. It works great except the picture gets slightly brighter and MK> dimmer. Could this be caused by the wire going from the flyback to the MK> cathode? When I first put it back togeather I could hear it arcing a MK> little like the suction cup wasn't all of the way down. It doesn't MK> make a arcing noise anymore.

MK> The model number of the tv is RNH4601 WA01 MK> The Chasis model # is 26B1-06AA MK> Manufacture date October 1987

Mike,

It could be the flyback assembly alright. The flickering might be the the g2 voltage jumping around. If you smell something like burnt toast around that area then the flyback *is* toast. Otherwise it may be a video problem.

A*s*i*m*o*v

... :

I know about how the tube can possibley charge its self back up even after you discharge it. I usually keep a ground wire clipped on it when working on a tv. Thanks I just couldn't remember the word anode.

That's what I was implying. The guy really shouldn't be messing with it.

I dread to think what these people do "for a job" and if they have the same attitude to their work as they do with dealing with electrical equipment.

I'm a college student and I am a computer tech and I do my job quite well. I'm sure there was a time when you didn't know everything there is to know. I'm the first to admit I don't know everything. No one does! I actually just forgot the name since I rarely work on Televisions. I'm still learning but I do know to discharge all of the large caps and the anode before you start working on a tv and to keep a ground wire attached to the anode while working on a tv.

I am very careful with electricity. I have been working with electricity all of my life and I used to work as an elctrician. I try to never work on anything hot if possible.

I hate how you just insult me like I am an idiot.

Thanks I'll check it or sniff it out.

- Mike

But you don't know a cathode from an anode? Gee that's some college you go to! There's multiple choice education for you.... How do you manage to get positive and negative the right way around?

Have you heard Kevin Bloody Wilsons song about electricians?

But you are.... You are......

FFS don't ever take up working with gas supplies.....

Hmmm...a licenced electrician once told me, emphatically, that, no matter whether the ground on the plug was on the top or bottom, it didn't affect which side the white and black wires were attached to... :-(

Tom

Thats sad.

What did I do to you? I came here to ask for help and all i get is FLAMES! Geez. And then to call me an Idiot, you don't even know me. Like I said I don't know everything there is to know and I'm trying to learn, but from what I can see nobody wants to help out anyone in this group..

Not to mention scary...

Tom

This has gone a bit far...if he isn't in college to study electronics, whay would you expect him to remember a word related to it? Even Ben Franklin got positive and negative wrong, and it's been a source of confusion for electronics education ever since. His explanation for his use of the word "cathode" was reasonable.

I know we all care about safety and liability here, but this guy has already passed my test. Model and chassis number, plus the month of manufacture, shows he "knows the drill".

Michael...what test equipment do you have? There are a number of things that could cause what you have described (weak capacitors being right up there, given its age). Have you done any measurements? A 1987 TV, it's likely an Admiral chassis, I think (?).

Tom

LOL I understand that a few years ago in London that one of these college educated "electricians" wired up two of the stars of a 3 phase supply feeding the lift system to the domestic supply in an 18 storey block of flats!

Smoke could be seen for miles around!

Bet any money you like that by this time next week you will know the difference between an anode and a cathode. How's that for help? ;-)

No it wasn't but I do appreciate your "which way does electricity flow" point Tom.

It is a very old and basic argument which after a lifetime of electronics, I can never answer but an anode is still connected to the electron surplus.

Dave

Just to add to this discussion...I always used the word "pancreas" to help me remember...PositiveAnodeNegativeCathodeREAS.

We apparently agree to disagree...about Michael, but not about which way the electrons flow.

Tom

I wonder how these kids would have got on playing with EHT pumped straight out of a 50 Hz mains tranformer at several mA?

Loads of fun!