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Zenith Z-159 w/ flakey hard drive (Was: Something Interesting

k2x4b524[

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I have one for you, i have acquired an old Zenith Z-159 with a 360kb flop and a 20mb hdd, full height Authentic IBM. It spins up, then spins down. Turn off, Spins up, spins down. I whacked it, spins up, clicks, spins down. Whacked it with blunt object. Spins up, chirps cheerfully, works normally, hellaciously slow. It's the second hard drive to do that to me due to age. A New-Old stock drive i'd gotten, hadn't been spun up in 20some years did the same thing, whacked it, not it's flawless. Here's my question, is it possible that the Head Actuator / Arm gets stuck from disuse and needs come encouragement?
 

MikeS

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Dec 23, 2005
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I have one for you, i have acquired an old Zenith Z-159 with a 360kb flop and a 20mb hdd, full height Authentic IBM. It spins up, then spins down. Turn off, Spins up, spins down. I whacked it, spins up, clicks, spins down. Whacked it with blunt object. Spins up, chirps cheerfully, works normally, hellaciously slow. It's the second hard drive to do that to me due to age. A New-Old stock drive i'd gotten, hadn't been spun up in 20some years did the same thing, whacked it, not it's flawless. Here's my question, is it possible that the Head Actuator / Arm gets stuck from disuse and needs come encouragement?
Yes .
 

ZOBEX

Member
Joined
Oct 7, 2009
Messages
37
I have one for you, i have acquired an old Zenith Z-159 with a 360kb flop and a 20mb hdd, full height Authentic IBM. It spins up, then spins down. Turn off, Spins up, spins down. I whacked it, spins up, clicks, spins down. Whacked it with blunt object. Spins up, chirps cheerfully, works normally, hellaciously slow. It's the second hard drive to do that to me due to age. A New-Old stock drive i'd gotten, hadn't been spun up in 20some years did the same thing, whacked it, not it's flawless. Here's my question, is it possible that the Head Actuator / Arm gets stuck from disuse and needs come encouragement?

Yes they must be exercised. Also the bearings will take a set and if you power supply is marginal they will shut back down. MFM's will continue to spin even when the heads crash and rip off. Sounds like the bearings are getting stif from setting and need to be spun and possibly getting dry. And the power supply is marginal to start, not enough amps.
 

Chuck(G)

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With age, the "bumpers" on the actuator degrade (like all synthetic rubber, it seems) and get sticky. I've heard that the problem is that the plasticizers that make the rubber nice and soft start to exude from the surface of the rubber, gumming things up. You can see this happen on old tape drive pinch rollers.

I wouldn't expect the problem to magically go away.

Conceivably, you could repair this by going into the HDA and replacing them, but that requires clean-room conditions.
 

k2x4b524[

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Tacoma, Washington, USA. Zip code 98404
oh i understood that perfectly clear, but i also know that if you don't sneeze on the thing or stir up dust your ok. so back to my question, can the things be lubed, and if so, what lube does it use?

And Ahm. You are now to be known as "Mr. Rude." :cool:
 

kishy

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I've been told by a surprising number of people that, "back in the day", they'd open up hard drives to unstick parts then close them up, no biggie. Drives would keep on kicking for years before the next signs of problems.

While true that you can correct some issues on your desk, keep in mind any repair you make is should be considered "only temporary" if the lid is off outside of a clean room. There's a lot (read: enough to make you vomit at the thought) of stuff in the air that can, conceivably, screw up a hard drive if it doesn't get caught in the filter first.

Sure, the drive MAY then last until the motor quits...but if you approach it as a temporary solution your expectations won't be so high.
 

Ole Juul

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Coalmont, BC, Canada
You can use your shower for a relatively dust free environment. Hose it down first. Built a simple HEPA like system for 100 bucks (or less). Use a cheap to build clean box. Check out what biologists do - especially on the hobbyist level. Remember people have been doing culture transfers on petri dishes for a long time. Many myco folks do it at home.
 

ZOBEX

Member
Joined
Oct 7, 2009
Messages
37
I was actually lucky enough to pop the top on both the drives, the rubber hadnt degraded, but i'm thinking about taking the top off again to relube, is that possible? if yes, what kind of lube should i use?

IF you are getting enough current to spin the drive and there is no sticky rubber, THEN the problem is an old one. The SERVO zero stop is not aligned correct. This is or was a very common problem. For several years I had a home hobby business of recycling hard drives when people would just toss them. I could buy a "dead" hard drive for parts at $5 and then resell them for $50. On larger or better quality drives there is an adjustable stop for the servo arm to bump into and then calibrate itself for the index track. What happens is metal will change shape with time due to any number of reasons so after some use the servo arm stop and thus the position of the servo arm and head do not fully come over the zero track on the disk platters. If the stop is too far wide it will have some difficulty positioning the head over the zero track. If the stop becomes too far into the center of the drive the head can never find the zero track. On big drives such as MFM, RLL or ESDI if the drive has a hard time picking up that track or can't find it at all, this may require repositioning the bump stop. Often that is a lock down tab held down with a through bolt on a slotted guide. I would adjust the servo stop till the drive picked up servo with no problem.

I fixed one MFM this week for a guy restoring a generic XT, set the servo, lubed the exposed main shaft bearing and polished the static drag contact brush. Kind of weak on the platters but runs MFM OK but would not go RLL. I liked it when you got hard drives by the pound not mega byte.

But remember any dust will cause a head crash into the platter or cause a dead spot on the platter.

Z
 
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ZOBEX

Member
Joined
Oct 7, 2009
Messages
37
I have one for you, i have acquired an old Zenith Z-159 with a 360kb flop and a 20mb hdd, full height Authentic IBM. It spins up, then spins down. Turn off, Spins up, spins down. I whacked it, spins up, clicks, spins down. Whacked it with blunt object. Spins up, chirps cheerfully, works normally, hellaciously slow. It's the second hard drive to do that to me due to age. A New-Old stock drive i'd gotten, hadn't been spun up in 20some years did the same thing, whacked it, not it's flawless. Here's my question, is it possible that the Head Actuator / Arm gets stuck from disuse and needs come encouragement?

You did not specify the HD model number, check if there is an outisde servo index with an arm going through a photo cell or micro switch. Some of the first ones use a photo cell with an arm breaking the light circuit. That light circuit can get dirty as well. If the dirve is handled wrong that outside servo indexing circuit can get messed up. I have one here that I had to work over for just that reason. Some clown grabbed the drive and slamed it into something on a work bench. I had to epoxy and re-adjust the parts.

Z
 

kishy

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Aug 22, 2009
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Zobex, I may PM you once I get my old miniscribe opened up. It "can't find track 0" which tells me the stop has been shoved out of place and as a result the drive is "out of calibration". Hopefully you could guide me through correcting that. Need to find an extra tiny torx bit though, the size it uses is smaller than considered "standard" and may well be proprietary.
 

ZOBEX

Member
Joined
Oct 7, 2009
Messages
37
Zobex, I may PM you once I get my old miniscribe opened up. It "can't find track 0" which tells me the stop has been shoved out of place and as a result the drive is "out of calibration". Hopefully you could guide me through correcting that. Need to find an extra tiny torx bit though, the size it uses is smaller than considered "standard" and may well be proprietary.

What Model is it ?? If it sweeps when you start up and goes " weep weep weep " searching and finds nothing, it may just go and shut down. If the track under the index is wore out it might never find the servo track. That track is written at the factory and without factory equipment you can not rewrite it.

Tonight I am fixing a 30mb rodime , I never liked those, a lot of noise and vibration.

Z
 
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