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Weird noise from Macintosh SE FDHD
- Thread starter MacLover
- Start date
Yes, sadly, the others are right. The hissing was the dying gasp of a CRT whose vacuum-seal nipple had just been snapped off. It is now an ex-CRT, but a beautiful objet d'art still. It can serve in poignant testimony that nature abhors a vacuum.
If you attempt to power up the Mac in its present condition, the high-voltage power supply will struggle valiantly against the loading by vast quantities of conductive, ionized gases. A beautiful audiovisual multimedia pyrotechnic display will soon be supplemented by a strong olfactory component, and then, ultimately, by extreme badness.
If you attempt to power up the Mac in its present condition, the high-voltage power supply will struggle valiantly against the loading by vast quantities of conductive, ionized gases. A beautiful audiovisual multimedia pyrotechnic display will soon be supplemented by a strong olfactory component, and then, ultimately, by extreme badness.
aww, the hiss of death...heard it, a few times, over the last several years..That would be the air being let into the CRT as the glass was cracked, sadly.I wouldn't power that machine up again until you replace the CRT.
not that hard to replace the CRT....too bad, you're not near by, I have a bunch of good used tubes, with nary a burn-in..
on some compact macs, they were cursed with severe screen ins
before the era of after dark. . . . .... . . . . . . . . . . . . . ...... . . . .... ...
This odd hissing noise: did it occur during the repair, or after you tried to turn it on? And was it fairly short-lived, or did it exist until the machine was turned off?
If it was short-lived and happened with the case off while you were fixing something, it's probably a broken CRT.
However, if it only occurs when it's turned on and disappears when turned off, it may be a bad component on the analog board.
Some more data would be useful.
If it was short-lived and happened with the case off while you were fixing something, it's probably a broken CRT.
However, if it only occurs when it's turned on and disappears when turned off, it may be a bad component on the analog board.
Some more data would be useful.
yes, I concur...but it does sound like the neck was cracked, if so,
then the CRT is toast....they are very fragile around that area.
a few yrs ago, I was working on a friend's SE, and accidently bumped
that neck, and heard the HISS of death......
lucky, I had a couple of very nice, and virtually new CRTS...and
quickly changed it out...turned out it was a gooood thing for my
pal, as his 'original' CRT, suffered from burn in..from MS word..
weird seeing those ghostly images burned into the tube....
for a few yrs, after dark sold a boat load of those programs, i.e. flying toasters, fish, etc....
Thing is, the computer went through some rough shipping (the plastics from the reset and debugger switches was coming off and when i opened the case, I saw that the video board fell off and two pins were bent on the CRT) so I bent the pins back into place, reattached the video board, and powered it up. I then heard the hiss and yanked out the power cord in panic. The noise disappeared immediately.
PS: The first time I started it up, after I got it, there was nothing on the screen, signaling something wrong in the CRT/analog board area but I did get a normal startup beep and I heard the fans, meaning the logic board and the analog board (or at least the parts that power the logic board) are OK.
BTW: how can I tell if the CRT was cracked?
PS: The first time I started it up, after I got it, there was nothing on the screen, signaling something wrong in the CRT/analog board area but I did get a normal startup beep and I heard the fans, meaning the logic board and the analog board (or at least the parts that power the logic board) are OK.
BTW: how can I tell if the CRT was cracked?
Now you're giving us key information not present in your original post. If the hissing sound only occurs when power is applied, then it's not a cracked crt. When you originally wrote that you reattached the board and then hissing occurred, you gave us no details about intervening events (leading us to believe that there were none).
Several electronic sources of hissing exist, so without a soundfile to listen to, it's hard to provide a definite diagnosis. But a common source is a high-voltage problem (e.g. a loose HV connector, damaged insulation...). Did you operate it long enough to see if the crt displayed something/anything?
Several electronic sources of hissing exist, so without a soundfile to listen to, it's hard to provide a definite diagnosis. But a common source is a high-voltage problem (e.g. a loose HV connector, damaged insulation...). Did you operate it long enough to see if the crt displayed something/anything?
Even though the noise was not air entering the CRT, I don't think you can completely rule out a cracked CRT, though. If the CRT had air in it, I imagine the analog would make some weird noises.
This little Mac must have been really jarred to knock off the video board and bend pins in the process. This much force could have easily cracked it... Most, if not all CRTs make a quick little hiss or crackle noise when you first turn them on. Are you sure this isn't what you're hearing?
This little Mac must have been really jarred to knock off the video board and bend pins in the process. This much force could have easily cracked it... Most, if not all CRTs make a quick little hiss or crackle noise when you first turn them on. Are you sure this isn't what you're hearing?
No I shut it off too quickly because I thought something would start burning in there and I didn't want any additional components being damaged or a fire being started
About the hissing, I remember it being loud and a little on the high-pitched side
BTW, sorry about my post being ambiguous, I was in a bit of a hurry
