Author Topic: 1990s Television Sets  (Read 284 times)
Cole D.
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1990s Television Sets « on: February 18, 2024, 09:01:34 PM » Author: Cole D.
What were considered as good television sets in the 1990s?

I in my room used to have an RCA (Thomson) 19” TV from 1994. I remember the remote was oblong in shape and had gray and purple buttons. That set I’m guessing was a cheaper one at the time because it didn’t have any input or output besides the cable jack and it didn’t have stereo speakers.

What was funny with that set was when you turned it on, the icture would jump up and down, and if I smacked the top of the unit, it would straighten out. The sound on that set also always had a faint buzzing to it, even if you muted it, there was still a humming.

Was Zenith considered a junky brand? As most of those I ever saw had problems. I remember a 19” Zenith from 1995, that went out completely, when you turned it on, there was just a black screen with a white line.

My grandparents also had a 25” or 27” Zenith (I forget which)  from 1995, and that set nearly caught on fire. One day my grandfather was watching the news while my grandmother was coking dinner. She said that there was suddenly a terrible odor, and she went around the corner, and there was black smoke coming out of that set! My grandpa quickly set it outside. No idea how he moved the heavy thing! It was probably 5 or 6 years old at the time.
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Re: 1990s Television Sets « Reply #1 on: February 18, 2024, 11:41:39 PM » Author: RRK
Picture jumping and a bang sound is normal for all color CRT in TV's and monitors, it is a degaussing coil working.

Here in ex-USSR, SONY's Trinitrons were considered the best. Though many really 'made in Japan' sets by others like Toshiba worked very well too, and even some Korean LG's. A bit later, may be in early 2000s we were all drooling for Pioneer and Panasonic plasmas, these were super cool, but prohibitively expensive.

In the world of monitors, Mitsubishi Diamondtrons  were the top monitors, until it all get taken over by LCDs.

Interestingly, while the electronics in the early native Soviet color TVs were total unforgivable crap based on the mix of stone age semiconductors and tubes, old triangle 'delta' shadow mask CRTs had some notable advantage in image smoothness over later 'stripe' designs. Being a b. of course to adjust convergence and purity, that's it...

« Last Edit: February 19, 2024, 12:02:33 AM by RRK » Logged
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Re: 1990s Television Sets « Reply #2 on: February 18, 2024, 11:42:17 PM » Author: Patrick
I remember a Zenith sign in or around Illinois.  It might have been this one.  It stated "The quality goes in before the name goes on", but then ironically only a fraction of the bulbs would illuminate.  I'm not sure how their quality was overall, but my family had a Zenith throughout the 1990s.  I don't believe anything ever went wrong with it.  My brother eventually took it to college.  It was this model.
« Last Edit: February 19, 2024, 10:59:50 PM by Patrick » Logged

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Re: 1990s Television Sets « Reply #3 on: February 19, 2024, 07:39:09 AM » Author: Mandolin Girl
From what I was told by the guy that repaired  my Pioneer VCR, it was just a rebadged Philips unit.  :wndr:

I was very impressed with him, as had the VCR for ages before it was fixed. He told me that he had spent a long time tracing the fault, but then he realised that he had guessed wrong as to what the problem was and that he wouldn't be charging for the time he had wasted.  ;D
« Last Edit: February 19, 2024, 07:42:36 AM by Mandolin Girl » Logged

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Re: 1990s Television Sets « Reply #4 on: February 19, 2024, 09:23:52 AM » Author: Medved

What was funny with that set was when you turned it on, the icture would jump up and down, and if I smacked the top of the unit, it would straighten out. The sound on that set also always had a faint buzzing to it, even if you muted it, there was still a humming.

This sound to me like some oxidized connector and/or dirty trimmer/pot for vertical frequency adjustment (once you "smack" it, the contact recovers) - in that case the picturewould be wildly rolling up or down and after the smack becomes immediately stable.


It won't be any normal function (the demagnetization,...), as that won't need you to "smack" the set.

However it may be bad contact on the demagnetization control PTC: It uses to contain two pucks (valid for a 3-pin PTC), one in series with the coils controlling the demagnetization current itself, second directly across mains, designed for a bit higher temperature and intended to keep the first one hot enough it really does not conduct anything.
But if the second one has a bad contact (internally, within the PTC assembly), the first continues to draw some small current to maintain its temperature, this current is then causing the picture to shake when the picture source is not synced with mains (so usually when coming from VCR or so). Once the contact gets restored, the second PTC warms up, causing the first one to stop conducting at all, so the shaking disappears. If this is the case, the shaking would be disappearing rather gradually (over about half a second, so still pretty fast, but it won't be snap-immediate).

Some CRT monitors used a 2-pin PTC and a timer switch (a relay controlled from the main function control microcontroller), so did not suffered from any such shaking. In such case that relay could be defective.
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Re: 1990s Television Sets « Reply #5 on: February 19, 2024, 12:21:09 PM » Author: Laurens
The buzzing you heard likely comes from the vertical deflection coils which make a faint humming sound at either 60 or 50hz.

Both Philips and Sony made great televisions. However, in the 90s, the quality of TVs had already started to dwindle, with color TVs having become a commodity appliance with tremendous competition on the lowest price. Even quality manufacturers felt the pinch. B&O bought Philips chassis for their lower end products instead of their own designs. Still good stuff, just not as over engineered i guess. Loewe and B&O were considered the best of the european brands, but Philips was also really quite good. From outside Europe, Sony was one of the best. I have a little 37cm Sony Trinitron TV with built in VCR, and it has beautiful vivid colors, better than any of my LCD monitors. Of course resolution and sharpness are worse, but for certain applications (watching old tapes or 480p video from Youtube) it's not necessarily a downside.

What people often forget, was that it was completely normal for a TV to break after like 8 years and to get it repaired for a quite significant sum of money. The 90s (and older!) TVs could survive for decades, but that does not mean that nothing had to be done to keep them alive.

A very common fault in *any* brand of TV was broken solder joints at the 27.000v high voltage transformer. Easy fix. Also common were dodgy contacts of side contact circuit boards, dodgy tuner preset potentiometers, and broken contacts on the CRT neck circuit board.
A rolling picture until you smack it, means that the vertical hold potentiometer is either dirty or has a loose solder joint, or in general a loose solder joint somewhere in the vertical deflection circuit.

Smoking TVs were also common. Rifa or Wima filter capacitors (similar to the ones in some fluorescent ballasts) would burn out after 15-30 years. The aforementioned loose solder joints in the HV/flyback section could also char the circuit board, if left to arc and sputter for a while 'because it worked again after i slapped it'. If left to arc and char the board, whole sections of the board had to be cut away and repaired manually, which is a significant amount of work. And especially notorious were the mains switches in the Philips K40 chassis TVs, which tended to catch fire. The solution to prevent that problem was easy enough - either replace the entire switch, or cut away some specific piece of plastic on that switch. I don't know exactly - those TVs are 20 years older than i am. Despite that, the K40 is considered to be one of the best TVs ever made by Philips. 

Analog color TV is one of the most amazing inventions of all time. There are so many clever engineering tricks, so many things could be slapped onto the existing signal while still retaining backwards compatibility. In my eyes, it's the pinnacle of analog electronics engineering. Yet, it's become so mundane, that people walk by any old CRT tv and probably don't think a second about the highly refined technology that's in there.
« Last Edit: February 19, 2024, 12:25:59 PM by Laurens » Logged
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Re: 1990s Television Sets « Reply #6 on: February 19, 2024, 01:13:29 PM » Author: RRK
But I hate interlaced rasters of analog TV! Causing annoying flicker and generally incompatible with any digital video processing. SECAM color in the USSR was even more hateful. Extra 25Hz flicker and bright color 'flares' on even mild phase distortions. Those idiots followed some French invented idiocy on adopting it...

Older tube-based color TVs were natural fire-bombs. One of the most problematic part was high-voltage regulator circuit. Color CRTs dislike anode voltage variation, but anode current changes with picture brightness. Modern circuits cope with this using low-impedance high voltage rectifier, but it was not possible in the early years. The solution was to use a shunt regulator triode tube which ran in parallel to the CRTs and consumed all the HV power when the CRT was dim. The circuit was horrendously dangerous and inefficient, this tube dissipated up to 25W and worked at 25kV anode voltage. A chassis edge where this was mounted was subject of high heat, high voltage and ozone, at the same time, so plastic insulation quickly deteriorated, leading to breakdown and fires. This regulator tube also emitted a significant amount of x-rays (!) and required metal shielding, exaggerating heat problems...
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