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Old 07-30-2017, 10:37 PM
CPQ5360 CPQ5360 is offline
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Casio TV "green screen of death"

As the years go by, and I occasionally look at Casio portable LCD TVs on eBay, I find more and more of them with the "green screen of death", in which the only sign of life the set gives is a green screen and no sound when powered on. It's normally just a symptom of the batteries going dead, but on afflicted sets, it's permanent, even with new batteries.

I find that the mid 90s sets (TV-470, TV-480, TV-600, etc) are starting to have it happen, and sets from before then (TV-400, TV-430, TV-800, TV-1000, many others) are pretty much guaranteed to have it now.

I've never been able to find a single account of someone attempting to diagnose or fix this problem. So I thought I'd throw it out here - has anybody here? Does anyone figure it's probably bad SMD capacitors, or something else?

I've got a TV-400 that was working fine when I acquired it in 2012. A couple of years later, it inevitably went green. One of these days I want to crack it open and see what's up, although god knows I'll probably never be able to fix it since I've never worked with SMD stuff.
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Old 08-07-2017, 10:40 PM
CPQ5360 CPQ5360 is offline
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I decided to bite a bullet recently, and bought a "working perfect" Casio TV-1400, mfd. August 1990, on eBay (only because it was part of a lot that included a Sony Watchman). As I predicted, it was totally non-functional (I'll never understand what possesses eBay sellers to declare an item they know nothing about as "perfect working").

This one behaves a little differently, though - instead of the green screen of death, this one simply emitted a horrific full-volume screeching noise from the speaker (volume control did nothing) whilst green lines flickered across a white display. After a few minutes of doing that, now it just shows a blank white screen and no sound, with no tuning indicator or any other sign of life.

I decided to tear into this set, as well as my dead TV-400, and see what they look like inside, and I discovered a commonality between both of them which, for some reason, I didn't expect - quite extensive corrosion. Both sets had what appeared to be just minor corrosion in the battery compartment, but the corrosion of the circuit boards inside is quite severe.

Between this and the fact that I do occasionally find early Casio sets still working normally on eBay, I'm now wondering if the numerous dead sets I find isn't due to age-related failure, but rather damage-related failure. And I wonder if the many on eBay showing the green screen of death isn't simply sellers trying dead batteries in them. Interesting, nonetheless. I'm now more motivated to find a good working early Casio set.
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Old 08-08-2017, 09:18 AM
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etype2 etype2 is offline
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For what it's worth:

I have a good collection of micros. Many are Casio. The green screen disappears once a signal is imputed, or a common problem the OFF/VHF/UHF switch is bad or needs cleaning. Giggle the switch and the image pops in and no green screen.

Other times, the set just needs to "wake up" for several minutes after power is applied.

Battery compartment cleanup usually works.
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Old 08-09-2017, 08:00 AM
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Bad caps, been there, not worth wearing a magnifier.
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Old 08-09-2017, 04:39 PM
CPQ5360 CPQ5360 is offline
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Quote:
Originally Posted by etype2 View Post
The green screen disappears once a signal is imputed
That's not how they normally work. When there's no signal, the set is supposed to show a white screen with the tuning indicator at the right scrolling down as it scans for channels. When the green screen happens, it covers the entire screen, even the tuning indicator, which is supposed to be a permanent fixture of the display.

When my TV-400 started to fail a few years ago, I did indeed observe that it would take a few minutes to wake up when you turned it on. Then eventually the green screen became permanent.
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Old 08-09-2017, 08:54 PM
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This isn't specific to Casio TVs, but in my experience, SMD electrolytics from the 80's until about 1995 have a 100% failure rate. Most leak causing corrosion, but some just dry out and go open circuit.
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Old 08-09-2017, 09:11 PM
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etype2 etype2 is offline
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Quote:
Originally Posted by CPQ5360 View Post
That's not how they normally work. When there's no signal, the set is supposed to show a white screen with the tuning indicator at the right scrolling down as it scans for channels. When the green screen happens, it covers the entire screen, even the tuning indicator, which is supposed to be a permanent fixture of the display.

When my TV-400 started to fail a few years ago, I did indeed observe that it would take a few minutes to wake up when you turned it on. Then eventually the green screen became permanent.

Your exactly right. Just acquired a Casio TV-7. Unpacked it, popped in batteries and had the green screen with active scan. Attached my DCB and boom, nice clear signal with sound on Ch. 3. I've had other sets do this as well, but still work. I guess I don't use them enough to watch them fail.

These sets are so cheap on EBay, not worth my time to try and fix when one of them fails, I just get another one on EBay.
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Old 08-12-2017, 02:56 AM
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Quote:
Originally Posted by andy View Post
This isn't specific to Casio TVs, but in my experience, SMD electrolytics from the 80's until about 1995 have a 100% failure rate. Most leak causing corrosion, but some just dry out and go open circuit.
Second this. I've become surprised just how much of my collection of everything from portable TV's to handheld GPS units to early ebook readers has fallen into needing capacitors replaced because the SMD's are all failing.
There's a JVC GY-X2 in the other room that needs it done. There's over 150 capacitors in that son of a....
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