Oh, it's ultra weird then. Did you successfully go through the geometry procedure after the replacement ?Let me take a look at the schematic.
Edit: Actually, it was one of these 2SK3262 ones
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Oh, it's ultra weird then. Did you successfully go through the geometry procedure after the replacement ?Let me take a look at the schematic.
Edit: Actually, it was one of these 2SK3262 ones
Yeah, it was a one off that the mode got garbled up and the horizontal frequency went out of range during the procedure I think. It works and looks fine having replaced the one mosfet that burnt out.Oh, it's ultra weird then. Did you successfully go through the geometry procedure after the replacement ?
The problem is that given the schematics there are capacitors internal to the flyback as well, and the type isn't specified (no way to know if it's likely to age or fail). That issue is a needle in a haystack. I read about insulation issues inside flybacks, temperature differences cause expansion/contraction cycles that may cause intermittent shorts (with the arc possibly melting some insulation material and fixing the problem for some time).Oh, by the way, I think you might be on to something about the popping issue. After heating up the room where I have my monitor, there isn't any popping during the initial warm up. So it might very well be a cap issue only and not flyback or tube shorts, if there is any logic to that. Would heat tighten up a cracked flyback or keep the elements in the tube from shorting out? I haven't bothered to pop the case and check, in keeping with the philosophy of not fixing what isn't broken.
Very interesting findings, thank you for writing this up. Presumably my issue and that of many others is the same as yours, wherein the loss of focus/restoration of focus is associated with the popping sound that you have localized to that spark gap. The issue seems to be progressive yet intermittent so all of these factors, thermal degradation among them, may contribute to the eventual failure of the monitor. If we were to do an autopsy of one that has actually failed due to this phenomenon, we might learn more about it, I think.The problem is that given the schematics there are capacitors internal to the flyback as well, and the type isn't specified (no way to know if it's likely to age or fail). That issue is a needle in a haystack. I read about insulation issues inside flybacks, temperature differences cause expansion/contraction cycles that may cause intermittent shorts (with the arc possibly melting some insulation material and fixing the problem for some time).
What I can tell is that my assumption about the grey foil capacitors was probably wrong (unless the popping issue you describe is different from mine). I finally put back my ill FW900 in use after doing the 2nd part of the restoration job I had planned since it was open. It had a random habbit of sparking SG901 sometimes with a brief expansion of the display area and out of focus, fixing itself a second later. It still has it now despite having replaced all of those grey capacitors with top notch polypropylene ones. I could measure voltages with less noise with the new capacitors though (not surprising given the performance level of the originals), but it's not sure the change is noticeable visually.
What I figured out is that the ground tracks in the power supply are extremely noisy. I suppose electromagnetic interferences are emitted by the switch mode part up to transformer T630 and picked up by any metallic part around. The only way I found to mitigate that is to add extra chassis connections on ground tracks all over the G board *edit* and add an extra 680nF/25V ceramic cap between pin 2 and 3 of IC651 to help stabilizing heater voltage. Maybe that's nitpicking but cleaner power supply cannot be bad for an analog device.
5 connection points with 2.5mm² cables fasten on clips which are connected to the 2 appropriate strips present on the G board chassis. Vs one single, maybe 1mm² cable originally. On the top of that there was a ferrite cylinder around it which prevented high frequency noise from being grounded, I don't see any smart reason for that.
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Oh, and BTW let me introduce a pet I adopted some time ago for electronic investigation. Of course with cathodic display.
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This is a nice try but you got everything wrong.Because of the unusual G2 drift effect we have with these monitors being caused by a circuit that compensates for the low emissivity of the CRT during warmup, maybe the overbrightness and excessive compensation on the "cutoff amp" is related to the focus loss somehow through the FBT?
As described in the second link in the paragraph above, maybe disabling this circuit on the FW900 may impact the state of affairs? I'm only looking at it from the word association point of view here since my electronics knowledge is limited, and I'm really only tracing the lines on these schematics here.
Edit3: Attached CR1 chassis (F520) service manual as reference. The design in that area seems more advanced at a first glance, but the 520 series also introduced a "picture effect" feature akin to the picture mode settings on modern TVs with professional, standard, and dynamic modes altering contrast and color via presets, I suppose.
I don't mean to be flippant, but to me there are two issues here that may be conflated by the terminology regarding G2 etc., etc. after having read further in the badcaps thread. There is the gradual change in calibrated brightness over time going out of whack that is probably a result of the progression of these components as you said, and then there is the overshoot at cold temperatures caused by this "drift correct" circuit on G_ chassis designs. The "drift" referred to here I guess is different from the long-term G2 drift problem we are familiar with, and refers only to the low output on startup of the tube. By that hypothesis, I'm still thinking that the temperature dependence and sporadicity of the snap, crackle, and pop we are getting has some relation to the characteristics of whatever that transistor 2SC2412K (spec sheet attached) has in that circuit. It would be possible to test this by grounding pin 17 on that IC and then varying the environment at startup to see if the problem could be induced by changes in air temperature with the circuit active or not, as I seem to think. This purported phenomenon of course interacts with the aging of the components overall so we can expect the issue not to have occurred when the monitors were relatively new.This is a nice try but you got everything wrong.
If the issue were related to the G2 it would need a massive spike to cause such focus problems, and the activated sparkgap would be SG402, on the neck of the tube.
Also, even if the warmup compensation circuit impacts brightness like G2 does, these are two circuit parts completely unrelated. The trick used for compensation is pretty simple, it just keeps a low voltage using a transistor opening itself on the ground pin when that pin should remain grounded. And as the resistors/transistor lot heat up their characteristics change a bit, the balance state varies, that low voltage changes a bit, and what was a "bright" screen when starting the monitor becomes darker some time later.
The real G2 drift is probably related to the aging of components involved in the G2 regulation. A likely candidate is C919. It might have increased leakage current, lowering the G2 voltage at the A board input, or decreased capacitance leading to a less stable G2 voltage at the A board input which may then disturb the G2 regulation circuitry there. Or it could be any other component of that regulation circuitry aging.
Regarding the out of focus issue, it's apparently somewhere on the D board since replacing it entirely fixes the problem as far as I remember people reporting. I might find the culprit one day or another anyway, because my guinea pig 21" originally also had that zooming and out of focus brief issue from time to time. But after experimenting a lot on it and literally replacing half of the D board I do not remember to have seen it doing that again. So the answer might be in a change I did there but I didn't do on the FW900. Or maybe it was just a calm period before the issue comes back again, who knows ?![]()
Excellent. I'm glad to see you kept the Artisan, I thought you'd gotten rid of it or were trying to at least. Considering the above, have you ever had any issues with pops and the screen going out of focus that could be attributed to the flyback with the CR1s?CR1 user here (I still have my GDM-C520K Artisan). Picture modes do the following:
Using Professional as a baseline for contrast and brightness level, Standard boosts Contrast (white level), Dynamic boosts both white and black level. Dynamic's white and black level are brighter than Standard, and look washed out. I leave my monitor on Professional. Ditto with the F520 when I used to have one.
I don't mean to be flippant, but to me there are two issues here that may be conflated by the terminology regarding G2 etc., etc. after having read further in the badcaps thread. There is the gradual change in calibrated brightness over time going out of whack that is probably a result of the progression of these components as you said, and then there is the overshoot at cold temperatures caused by this "drift correct" circuit on G_ chassis designs. The "drift" referred to here I guess is different from the long-term G2 drift problem we are familiar with, and refers only to the low output on startup of the tube. By that hypothesis, I'm still thinking that the temperature dependence and sporadicity of the snap, crackle, and pop we are getting has some relation to the characteristics of whatever that transistor 2SC2412K (spec sheet attached) has in that circuit. It would be possible to test this by grounding pin 17 on that IC and then varying the environment at startup to see if the problem could be induced by changes in air temperature with the circuit active or not, as I seem to think. This purported phenomenon of course interacts with the aging of the components overall so we can expect the issue not to have occurred when the monitors were relatively new.
It may be better to disable this circuit to prevent the brightness overshoot on startup in general. I'd prefer a dim screen warming up to temperature on a slow curve to the harsh greenish looking image that you get when it oscillates above target considering it isn't mission critical whether the image is ready to go in 30 minutes or an hour for most of us.
Bear with me, I'm a rank amateur with no experience at all to be sure, and what seems like an intuition to me could be simply ignorance.So hopefully it's not annoying to hear me rehash the subject again and again based on my uncertain understanding of the issue. Let me know what you think.
I certainly don't intend to pop the case any time soon while my monitor still works well enough so corroboration may be left to future users. A few pops here and there won't damage things, right? Any chance of the spark gap going bad, and would that eventually lead to catastrophic failure in this case?
I see. In that case it comes down to the capacitors in the flyback itself being a major limiting factor on the lifespan of these displays. I wonder if there was a bad batch or if the operating environment is too harsh for them to survive very long without degrading. The flyback issue is common enough that most of the ones that have died (out of the ones that made it this far) seem to have it as a proximal cause. It's too bad that they stopped making them. I wonder if there's a warehouse somewhere with a bunch of these rare parts lying around.Don't worry, I was an amateur too a couple of years ago.
And with that monitor restoration project I've learnt a lot, piece of information after piece of information (and mistakes too), I think I have a good understanding of many things now, but not everything.
Anyway, really, don't focus on that transistor, it's nothing important, and it can't cause voltage spikes anywhere. It just creates a little offset, instead of having 0V on the ground pin of the amplifier to be the reference voltage, it keeps something like 1 or 2V using the current leaking from that ground pin of the amplifier and that transistor/resistance lot. Even if the transistor had an issue, the current can still leak through the resistance path.
You can short the transistor and connect the ground pin directly to the ground if you like, it's not harmful. But you may have to perform a WPB procedure after that so that the cut off values are set properly.
Regarding the sparkgap I can't swear it, but it's a very simple safety device, I don't think it can fail. It just uses the resistance of the air (or void) so that an arc is created if the voltage between both electrodes is too high. The focus loss and other display variations is just the consequence of the sudden voltage variation when it happens.
Hi there guys,
I´m new here, but an "old" CRT-collecting nerd. I have found 3 of these over the years and just snapped one with very low hours today. It is from 5/2003 and in perfect new-like condition externally and functionally. What I am using now is from 2000 and it is also in fantastic condition geometrically. Both are from Japanese production. The others (one of them SGI-rebadged) have seemingly severe problems in image, and with my knowledge in electronics and components I cannot say whether they are repairable.
In addition of FW900´s I have one brand new hp p1230 (rebadged Mitsubishi 2070SB), GDM-F520, 3 x GDM-W900, 2 x Iiyama Vision master pro 454 and Iiyama Vision Master Pro 514.
best,
mod
Hi there guys,
I´m new here, but an "old" CRT-collecting nerd. I have found 3 of these over the years and just snapped one with very low hours today. It is from 5/2003 and in perfect new-like condition externally and functionally. What I am using now is from 2000 and it is also in fantastic condition geometrically. Both are from Japanese production. The others (one of them SGI-rebadged) have seemingly severe problems in image, and with my knowledge in electronics and components I cannot say whether they are repairable.
In addition of FW900´s I have one brand new hp p1230 (rebadged Mitsubishi 2070SB), GDM-F520, 3 x GDM-W900, 2 x Iiyama Vision master pro 454 and Iiyama Vision Master Pro 514.
best,
mod
Seems like the adapters like even numbers.
Also, here’s a good tip for those using Sunix adapters (forgot what the other brand is called but they’re essentially the same thing):
if you experience image doing that whole buzzing thing or occasionally blanking to black (I only experience this in prime mode aka 1900x1200 @ 85hz), just run the monitor @ 84hz. Did this a couple months ago and I’ve never experienced any blanking or screen artifact ever since. 86hz should work as well. Seems like the adapters like even numbers.
I was playing Battlefield 4 at 2048x1536@85hz on my Sunix and was working fine. FWIW
If you mean things like convergence then WinDAS will be able to help you, at least somewhat.dont be so literally bro, by "perfect' I mean good enough where i cant tell the difference to the naked eye. im just trying to get the last bit there, its just slight uneven wobble on the sides, when my monitors warms up Ill retake some photos.
Have you tried 1920x1200@96Hz?if you experience image doing that whole buzzing thing or occasionally blanking to black (I only experience this in prime mode aka 1900x1200 @ 85hz), just run the monitor @ 84hz. Did this a couple months ago and I’ve never experienced any blanking or screen artifact ever since. 86hz should work as well. Seems like the adapters like even numbers.
I might consider selling that, yes. The one from 2003 with around 2000 hours of usage is coming here next week. Where do you live?Would you be willing to sell the mint condition FW900s?
Actually it seems Freesync is possible at least with some CRTs:This topic is a sad descent into madness. I just wish they started making crt's again. Crt with freesync would be just balls
Actually it seems Freesync is possible at least with some CRTs:
https://forums.blurbusters.com/viewtopic.php?t=3234
I don't know if it works well on the FW900, it seems to be "our" spacediver on that forum but I don't remember him telling it works so there may have been a failed attempt.
I never got the time to undertake that particular project!
thanks,
what surprised me was that they didnt mention any of the sunix DPU3000 D2 or D3 and only claimed to test at 70hz when i asked them. also they just referenced those 3 adapters which seem pretty ordinary:
http://www.sunixusa.com/product/h2v37c0/
http://www.sunixusa.com/product/d2v17c0/
http://www.sunixusa.com/product/d2v27c0/
is this the delock you mean? https://www.delock.com/produkte/G_87685/technische_details.html
i cannot find that Delock 87685 you say in amazon or pages in the US.
also do you know if that sunix D2 can be connected to a geforce RTX card as it is with just that wire it comes with?
anyone know what happened with the sunix DPU3000-D3? cannot find it anymore, or anyone know an adapter to use the fw900 with an RTX card, at 1920 x 1200 @90hz?
Probably impossible as no one ever did thatHow hard would it be to remove horizontal and vertical refresh rate caps from a CRT.?
Looks interesting!If your RTX card has a USB-C output and you don't need more than 1920x1200 96 Hz you can buy on the USA market these adapters:
Plugable USBC-VGA https://www.amazon.com/Plugable-Compatible-Thunderbolt-resultions-1920x1200/dp/B015X0CV1C
tested by other users with a pixel clock of 330-335 MHz
i asked sunix what happened with the D3, the replied:
"Our DPU3000-D3 has sold out due to shortage of the bundled DisplayPort cable. You may look into this model, DPU3000-D2, which is exactly the same model just with a different set of bundled DisplayPort cable;"
thank you Derupter for that valuable info, i dont have an rtx card but thinking about getting one since my graphics card got burned and smoked out
it worries me that no adapter seems to work without issues from what i am reading from users... so, i m thinking about getting both the suninx suggested by
jka and that "plugable" branded as well. and cross fingers