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IBM PS/2 Model 70 Hard Drive Error?

Conmega

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Recently I've picked up a model 70 with monitor and keyboard and mouse for about 50 dollars.
Other then it being one of the dirtiest computer I've gotten and the front plate being cracked and missing holding clips inside to keep it on (which I have since found some of the clips inside and glued them back on and glued the crack up) it was all there.
I got it and it had a long older style designed token ring card (actually wanted one and didn't know it was in there so that was good) and an EtherLink III card. It also has a math coprocessor installed and usually that's a rare addon to have in older machines but I'm not sure if it was rare for the PS/2? This is my first PS/2 so...
It was advertized as 'won't boot' and there were no pictures of it even being powered on so it could have been anything.
I turned it on and it was just CMOS battery errors. So I got a battery with charge threw it in and burned a Reference disk.
Everything was going smoothly so far, then I ran the 'test your computer' everything went fine all the way up to the 'fixed disk test' then I got this...
DSCF1950.jpg
So this is why I'm here.
When I start up the machine I hear the disk spin up and move it's arm around a bit which makes me think it should be fine but I guess it's test tells me otherwise.
I'm already on the hunt for a new HD if this one is dead. But I wouldn't mind trying to save this one as it seems to spin up fine... I already checked on it's board the (through hole) resistor values and that the 3 electrolytic caps weren't shorted and everything seemed fine...
Any idea's?
Thanks in advance!
 

Conmega

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I thought the controller was the board on the bottom of the HD... Sorry is it somewhere on the motherboard because it just slides in on a rail plugging into that weird 72pin MCA card on the riser board for the FD AND HD card edge connector.
DSCF1951.jpg
I guess I'll take a look at the motherboard. Sorry for my ignorance and thanks for the help!
If someone can describe where the HD controller area of the motherboard is that would be great too!
 

Stone

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I thought the controller was the board on the bottom of the HD... Sorry is it somewhere on the motherboard because it just slides in on a rail plugging into that weird 72pin MCA card on the riser board for the FD AND HD card edge connector.
No, that's only for IDE drives and still only partially so. MFM, RLL EDSI and SCSI drives have controllers that are on expansion cards.

I guess I'll take a look at the motherboard. Sorry for my ignorance and thanks for the help!
If someone can describe where the HD controller area of the motherboard is that would be great too!
It might not be on the motherboard. It could be on one of the expansion cards that are visible in the pic.
 

Conmega

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IDE? The PS/2's (or most of them at-least from what I know) Didn't use IDE for their Hard Drives.
I know they could have expansion cards to use IDE but that's not what I'm working with.
This Hard Drive is probably the drive it shipped with new.
http://en.wikipedia.org/wiki/IBM_Personal_System/2
Go down to storage they used ESDI drives which plug into a riser board which plugs into the motherboard. The riser boards is pretty much just a board an plugs no circuitry on it (other then three resistors and three caps). The hard drive is not interacting with the 3 expansion cards at all as two of them are token ring adapters and one is a Kingston memory expansion board. Heres a pic of what I'm talking about.
DSCF1952.jpgDSCF1953.jpgDSCF1954.jpg
 
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Stone

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IDE? The PS/2's (or most of them at-least from what I know) Didn't use IDE for their Hard Drives.
I know they could have expansion cards to use IDE but that's not what I'm working with.
Did you even bother to look at the pic you posted? It *clearly* shows an ESDI device. :)
 

Conmega

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I was trying to say I was working with ESDI not IDE unless IDE is the same as ESDI...
I said "I know they could have expansion cards to use IDE but that's NOT what I'm working with."
I was saying it wasn't IDE and that I wasn't working with an addon card to drive it.
Sorry for the confusion... So where is this ESDI controller located then? I'm assuming it would be on the motherboard right?
Do you know specifically where it is?
 

krebizfan

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IIRC, the drive is an ESDI drive but a small card is attached that contains the ESDI controller and adapts the drive to use the IBM socket. The drive and controller are one unit. Much the same idea as with IDE drives but without the cost savings of IDE.

Save that drive. Those slides are very difficult to find and might be useful if you switch to a SCSI setup.

IBM reference suggests trying advanced diagnostics or replacing variously the riser card, the drive, or the motherboard. Replacing all that could cost a lot. I suggest reseating both riser card and drive in case they came loose in transit.
 
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Conmega

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Well I checked the riser card the three resistors on it are ok but the three caps that are in series with the resistors are completely open... or atleast by what my fluke multimeter reads... They are little yellow through hole caps that resemble resistors but they are labeled C1,C2,C3 so... Have these been known to go bad? Can I just short them to see if it fixes it? Just trying to trouble shoot... Also I know how uncommon the 'sleds' are for the bottom of the drives even if the drive was bad I think I'd keep it as a paperweight or something and take the sled of the bottom so don't worry about me tossing anything ;)

I have a feeling it actually has nothing to do with it... Hm... I have someone looking for a new hard drive for me so if its not the hard drive itself it must be the motherboard... That would suck... I don't know why it would be the motherboard though considering nothing else seems to have had a problem and it seems fine... Just the ESDI controller gives me an error... You said it should be the board on the bottom of the actual HD right? So if I can get my hands on another one similar then I can swap the boards and it should work... Hm... Well I guess I have some tinkering ahead of me... Hopefully its not the motherboard...
 
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krebizfan

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You have the drive so examine it carefully and see if there is a board that can be removed and normal drive connectors underneath. I am operating from memory and the few reference books I have. Don't spend lots of money without verification.
 

Conmega

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There is no such adapter board. As I said this looks like the original drive that was in the machine at purchase it being an IBM drive.
Here are some pictures:
DSCF1955.jpgDSCF1957.jpgDSCF1958.jpgDSCF1959.jpg
 

NeXT

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I can second that I've heard before that the ESDI drive itself is an MCA device with a single channel controller onboard.

On the 55SX you literally have a ribbon cable that linked the top of the MCA riser card to the drive.

IBM_PS2_MCA_Model_55_SX,_hard_drive_cabling_and_riser.jpg
 

hwrdmltn

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This is an ESDI as everyone is in agreement with. Your problem: it is in IBM proprietary connection scheme between the card and the drive that IBM introduced with the MCA in an effort to get customers away from buying third party add-ons like they did for the XT/AT architecture which was much less expensive than IBM's, forcing customers to purchase IBM only hardware. Fortunately (unfortunately for IBM) it never "caught" on. So back to your problem - this controller hooks into the BIOS through software during BIOS boot, much like the XT did (because the interface was 8 bit only) and what this is telling me is the PROM code is running on the card (hence the error message) but the card does not see the drive (what the prom on the card does when the bios makes a call to the HD software hook) so my suggestion is to make sure you have a very clean connector on BOTH ends of that edge connector - I use an ordinary pencil eraser to clean the edge contacts - and alcohol IF there is some soluable gunk present (be sure it is dry before reassembling the connectors to the edge connectors). I have also used ordinary BRAKE cleaner from your local autozone or what ever - but be warned - while brake cleaner will not harm pc boards, it will eat some plastics. DON'T try to put some in a Styrofoam cup and expect it to be there in a few seconds. Also nail polish remover is also a great board solvent - similar chemical to what is used to remove (wash) excess flux after solder flow so that the flux used in the soldering process is removed and doesn't become a contaminant in time.
BTW these drives need to be low-level formatted before they can be used in any operating system - it is similar to RLL encoding but supposed to have much better error correction.
Just my two cents worth.
 

jharre

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I had this same problem with a drive that I picked up on fleabay for a song. The brown ribbon cable from the heads to the corner of the board (4th pic, on the right) had some white gunk in the connector that was preventing contact. Some quality time with an xacto knife to scrape it off the pins and some alcohol and swabs to clean up afterwards got mine going again. If you are lucky, just cleaning the connectors will help.

Mine went into a 55SX like NeXT shows above.
 

Conmega

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Well now I have another problem... I took everything apart to clean it up more then put it back together and flipped the switch and nothing... Nothing at all...
I reseated the Co-processor and I blew the dust out of the long power-supply with a compressor. Do you think I damaged the power-supply blowing the dust out? Maybe something happened when I reseated the Co-processor? Any ideas? I don't have the screw bits to open the power-supply at the moment but I did order them and should be here in a day or two. But what are these symptoms of? Just nothing at the flick of the power switch just silence. Ideas?
 
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Stone

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It could be an improperly seated component. Power supplies tend to shut down immediately upon sensing a short. See if something is mis-socketed.
 

Conmega

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I reseated all the chips all the ram modules and cleaned the edge on which the power-supply attaches to and still nothing...
I cant even hear a little bit of a whine from flipping the power-supply on it seems as if its not even getting wall voltage fro the wall but I know it is because I can hook the power cable to the monitor, monitor powers on, put the plug in the PS/2... Nothing...
 

smeezekitty

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Oops misread. You can try disconnecting the outputs of the PSU to see if it comes up.
Otherwise I suspect there is a problem inside the PSU.
 

Stone

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Plug another drive and nothing else into the power supply. Some PSUs won't fire up without a load. If nothing lights up the PSU is probably dead.
 

Conmega

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The power supply has a card-edge connector there's no place for me to hook up a drive separately. Hmm well I guess I'll have to wait till I get the security torx in the mail and pop it open. I must have done something when I was blowing out the dust.
 
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