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What's the trouble with that SE/30 ?
Posted by: galgot on 2016-01-07 04:36:55 Caps ? Thks.
Posted by: uniserver on 2016-01-07 05:48:15 yeah … nuked UE8 too more then likely. Charles
Posted by: 360alaska on 2016-01-07 05:56:26 Couldn't that possibly be an A/B issue?
Posted by: Paralel on 2016-01-07 06:03:00 Doesn't one horizontal line mean a loss of horizontal deflection? Although that line looks a little wider than I'd except for a complete loss of horizontal deflection. If I remember correctly, a total loss of horizontal deflection is a bright, pencil thin horizontal line.
Posted by: galgot on 2016-01-07 09:08:30 Thanks. Was wondering if it's easily fixable... Dunno anything about these. I usually buy laptops.
Posted by: Paralel on 2016-01-07 09:34:24 Easily fixable is always up to debate. One set of symptoms can have multiple causes. Given a certain pathway for a circuit, any point can be a potential source of failure, or even every point on that pathway could be a source of failure, but the given results will be the same, the circuit failing. So you could fix one thing, and its fixed, or you could fix thing, after thing, after thing, and still not have it corrected. You can't know until you get into the guts and get your hands dirty. Its sort of like saying "My car doesn't start, is it easily fixable?" Maybe, maybe not.
Posted by: Elfen on 2016-01-07 09:47:19 I agree with Parallel. Time to dig up the ancient scrolls and look up what could cause this. More then likely its the A/B but UE8 can also be a culprit.
Posted by: galgot on 2016-01-07 09:57:35 Easily fixable is always up to debate. One set of symptoms can have multiple causes. Given a certain pathway for a circuit, any point can be a potential source of failure, or even every point on that pathway could be a source of failure, but the given results will be the same, the circuit failing. So you could fix one thing, and its fixed, or you could fix thing, after thing, after thing, and still not have it corrected. You can't know until you get into the guts and get your hands dirty. Its sort of like saying "My car doesn't start, is it easily fixable?" Maybe, maybe not. I see , thanks...It's not yet my "car" btw 😉 posted the picture here to know if that kind of fault with the line on screen could be known to some of you before buying the thing.
Posted by: apm on 2016-01-07 13:58:57 Doesn't one horizontal line mean a loss of horizontal deflection? Although that line looks a little wider than I'd except for a complete loss of horizontal deflection. If I remember correctly, a total loss of horizontal deflection is a bright, pencil thin horizontal line. It's a loss of vertical deflection. Could be the analog board, even the yoke connector, but just as likely caps on the logic board. I had an SE/30 with this problem (no VSYNC from logic board) which went away with recapping. Also check UF8 and UG8 which are involved in generating VSYNC. UE8 failure would lead to corrupted video or possibly no video, but looking at the schematic it probably shouldn't cause this particular problem. Horizontal sync is fine. Without it there would be no high voltage so no picture.
Posted by: uniserver on 2016-01-08 04:02:10 to me it looks like dead caps on the mainboard, with a cooked UE8, and its out of focus, with the brightness knob turned up all the way. C15 3.9uf cap is known to pop on the SE/30 AB but that normally causes a vertical line. if it was a 128k, 512k, plus i would say yes the problem is in the Analog board. however because of my massive experience with the se/30 and seeing these pattern failures time and time again that is the reason behind my suggestion.
Posted by: Paralel on 2016-01-08 07:23:51 I would trust Uni on this, he's one of the masters of this kind of thing
Posted by: raoulduke on 2016-01-08 07:32:03 http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html#HorizontalLine #6? Vertical sweep circuit on A/B? Uni, it's a horizontal line.
Posted by: Paralel on 2016-01-08 07:48:48 But, as I said above, its not thin enough to be a pure vertical sweep failure (Sorry for getting horizontal and vertical deflection inverted, my brain was obviously not working 100%). I've seen pure vertical sweep failures, the line is literally pencil line thin, much thinner than that.
Posted by: raoulduke on 2016-01-08 08:30:24 Well so this is what you mean? https://68kmla.org/forums/index.php?/topic/23721-help-with-macintosh-se30-horizontal-line/ Is it possible the difference in width is a camera issue/parallax or something? Here's the manual's entire debugging process: "Single horizontal line is displayed 1 Replace analog board. 2 Replace video board. 3 Replace logic board. Retain customer’s SIMMs. 4 Replace CRT." So Apple's presumption was that the issue was in the analog board for this general symptom. Or alternatively it was cheaper to replace the analog and video boards before dealing with any issue, which would undoubtedly have been true. And then I guess sort of regardless, if there is a vertical sweep problem, might that not have to be dealt with in order to elucidate what else is failing?
Posted by: Paralel on 2016-01-08 08:37:54 It could certainly be a difference in imaging device, I can't discount that.
Posted by: uniserver on 2016-01-08 09:26:53 yes raoulduke, the op's problem is a horizontal line. yes.
Posted by: techknight on 2016-01-09 15:20:39 Horizontal line = vertical sweep failure. Period... Cause? Mostly whats named above... yoke connector, the TEA chip, logic board, etc....
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