22288Re: [midatlanticretro] How can I tell if my SMD disk head is crashing?
- Aug 12, 2011Darn, I was hoping the heads might just make some kind of whistling noise when loaded or something.
I didn't notice any kind of oxide flakes/chunks/powder inside the dust cavity when I removed the pack (although I have not tried wiping the inside with a clean white cloth to check for really fine particles yet). I will look for a way to remove the dust cover - I haven't been able to figure out how to get around the interlock thing yet (although I haven't tried much).
If you lift up the drive's main shell, there is a little window that lets you look into the drive cavity and see both the disk platters and the head assembly if you shine a light into it, although it was impossible to determine if a head was making contact or floating just by looking.
I do actually have a 2nd drive (in pretty bad condition) that happens to have a full set of heads, as well as 1 spare head still in a box. I'm not sure if the 'servo' head is identical to all of the others, but I believe it is. I also have a tester with head alignment card, as well as the little head adjustment tool thing, and a CE pack for calibrating things. Unfortunately I'm also pretty pressed for time.
One final comment - I reconnected the voice coil and attempted to let it go through its automatic startup process. The drive powers up, gets up to speed, and then attempts to do a 'load seek' operation, where the coil drives the head assembly forward about 2 inches or so, and then retracts quickly and triggers the 'fault' light. No whining noise or anything, though. I think this means that the servo head is failing to detect the dibit pattern on the out
-ChrisOn Fri, Aug 12, 2011 at 7:31 AM, Mr Ian Primus <ian_primus@...> wrote:Eek. That sure does sound like a head crash...
--- On Thu, 8/11/11, c f <christopher.h.fenton@...> wrote:
> When I loaded it, everything was fine for a minute or so, but then I
> began to notice a high-pitched whining noise coming out of the drive.
You can remove the dust cover to get a better look. I'm not sure about the smaller packs, but on the 300mb disks, look inside the center spindle - there will be a round hole in the center. By inserting something into that hole (like a pen), you can disengage the ball bearing catches that hold the top cover on, and lift off the dust cover. From there, use a flashlight to check for scratches on the disk surface.
> I retracted the head assembly, stopped the disk, and attempted to
> inspect it and the head assembly. Everything looked fine as far as I can
> tell (the disk is a bit difficult to examine, as you need to look at it
> through the tinted plastic of its cover).
> I then retried the same procedure, and the high pitched whining noise
> started again right away when I loaded the heads.
It's possible you're hearing something else... but a head crash should sound like metal on metal. A real terrible head crash would result in lots of brown oxide dust. Examine the pack for any trauma.
Even if it did crash, all is not lost - heads do turn up. I know a guy that might have some. I've never done a head replacement though - but it is documented in the manual (and it's a lot of work...).
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