Humbug, I say.

[unixronin]

Visible flyback lines on vorlon's Sun GDM5410 monitor today.  This is not a good sign.  Both of my monitors, it seems, are on their last legs, and there isn't really spare cash in the budget right now to replace them.  (Technically, there's cash in the bank, but I don't want to cut into it until we have to.)

We have one spare GDM5410 upstairs in storage, but I'm not convinced it's in much better shape than this one is.  They both seem to have the same problem — severe loss of screen saturation, requiring turning contrast all the way up to get any kind of decent saturation at all, which then forces turning brightness all the way down to have the screen not be washed out.  I suspect it's a design flaw on this monitor series, which is a terrible shame, because the completely flat (horizontally and vertically) CRT is the best I've ever used as far as image quality and lack of glare, and unlike an LCD, it continues to look good at resolutions which are not exact power-of-2 divisors of its native maximum resolution.

Comments

[mrmeval.livejournal.com]

At the top of the monitor? If so I can help fix it if you can solder, well slobber passably well. ;)

[unixronin.livejournal.com]

The GDM5410's saturation problem is uniform across the entire monitor. The GDM90W10's focus problem manifests mostly at the leftmost and rightmost 20% of the screen. Sometimes the 90W10 goes solid green. Both problems are "reset" by a power cycle, the focus problem being reset rather more temporarily than the solid-green problem.

[mrmeval.livejournal.com]

Are the lines green?

In some cases there is a 4.7uf 250v capacitor in the 200 volt line to the CRT board that goes bad which can cause some or all of those symptoms. Since I can't see them I can't say for sure.

If the lines are green it's most likely the CRT which is a Sony flaw. I'm not sure why but Trinitron's have that more than standard CRTs.

It's unlikely but I have seen the HStat block cause odd problems related to focus but it normally just shuts the unit down. It's the large red block with a clear cover, you sometimes see 'air bubbles' or charing between the cover and the potting compound. In severe cases the clear cover is cracked.

[unixronin.livejournal.com]

The flyback lines? When the 90D10 fails "solid green", yes, there are brighter green flyback lines visible, but otherwise, no ... when the GDM5410 did that, they were just slightly brighter lines superimposed on the display. So far it's only done it once.

I haven't opened up either monitor to look for visible evidence of failed components, on the assumption that if anything had failed completely enough to be visible to the unaided eye, the monitor wouldn't be functioning at all.

[mrmeval.livejournal.com]

The bright green one is probably the tube. If you can see an image with the bright green lines it's a highly likely it's the tube. If not it *could* be a bad connection on the green cathode drive transistor. With Sony's I go with CRT as I've seen it so often.

If it's the CRT I've fixed that by shorting the green cathode drive transistor from collector to emitter then turning it on. The excessive current will sometimes burn off the gunk and it will work for a time. Up to two years in one case. This will cause the safety protect circuit to activate. Not totally safe but safer on Sony's. I solder the short across it and power it on without hands stuck in the guts. It's a last ditch effort when a crt tester/booster is not available and I've only had it work on Sony's.

If the other is that intermittent you'll have to wait to track it down.

[unixronin.livejournal.com]

The bright green one is probably the tube.

Yeah, I was assuming that was an intermittent tube fault. It only ... well, ALMOST only occurs at first power-on. (I've had it occur once on waking up from powersave, but only once, I think.) The screen goes solid green with no picture and visible flyback lines. A power cycle invariably cures it.

If it's the CRT I've fixed that by shorting the green cathode drive transistor from collector to emitter then turning it on. The excessive current will sometimes burn off the gunk and it will work for a time.

A little scarier than I'm willing to attempt without a spare monitor on hand. :) Fortunately, solid-green-on-the-90D10 is an infrequent problem. Unfortunately, I'm having to powercycle the 90D10 as often as four times a day to "reset" the focus problem. (A power-cycle is probably not strictly required, but it's the only way to force a degauss, which — this is a hunch, I'll admit — is what's actually resetting the focus.)

[mrmeval.livejournal.com]

That one is odd. Focus is electrostatic, degaussing just effects the shadow mask. I suspect a CRT problem but ... I have seen a focus issue when the HV connection to the tube does not have the HStat hooked up right but that's permanent and is an assembly error.

Sony's HV resistor/divider block which has the HStat adjustment on it have a very high failure rate. If I had access to it I'd adjust the HStat and focus and see what each did while it's not working. HStat is horizontal static convergence and it will look kind of out of focus if slightly off or look like a 3D movie with three colors when way off.

I bought a 3000:1 contrast 19" LG LCD and it rocks.

[unixronin.livejournal.com]

This 90D10 has a bit of a history of not being able to get HStat perfect across the full width. If it's dead-on at one side, it's fractionally off at the other. I've always had to sett for a "good compromise". Ironically, that seems like it may have gotten a little better; convergence seems pretty close to dead-on all the way across now.

[unixronin.livejournal.com]

Are the lines green?

Huh ... the 5410 has visible flyback lines again today, and on closer examination, yes, they are green. (I also observe that picture size fluctuates wildly for a second or so when painting a large area of white er, make that "any large change in overall screen brightness" such as opening a new empty browser window. Another thing that seems to indicate imminent failure...)

[mrmeval.livejournal.com]

Green cathode problem most likely. I never have gotten a straight answer from a Sony rep.

Doing the trick mentioned earlier will destroy that for a time but can also destroy the cathode if it's a full on short. I"ve doing it several times. In one 32" set it fixed it perfectly for two years. In one smaller set that had a full short which activated the safety it did nothing. In another the green was terribly weak. Those are three examples. In most cases it fixed it for a few months. Two years is an exception. The ones that didn't work with had been severely used in bars where they were used 24/7.

Have you seen the Sun branded monitors recently? Would the be as good as yours would if new?

[unixronin.livejournal.com]

I haven't seen current Sun-branded monitors. Both of these are Sun monitors OEM'd for Sun by Sony. Sun calls the GDM5410 something like 'Sun 21" FD Monitor'. The most recent Sun-branded monitor I've seen is the 24" LCD that's, oh, probably a 7-year-old model by now.
(<python>It's verra nice.</python> I wish I had one. Or two. Or three.)

[mrmeval.livejournal.com]

I looked at Apple's recent one and it's stunning. It costs more that all the electronics I own.

I'm using the 3000:1 LG and am very happy with it but it does have some differences compared to a CRT. I thought it was picky on settings but there's an autoset feature that actually works. Time will tell how long it lasts.

I bet it doesn't bet the Viewsonic I had, that one still has a good picture tube and all I need to do is replace some capacitors if I get really motivated.