Broken Hard Drive

[VMSZealot]

I'm a menace and an idiot. I'm sorry, but it's true. I have a hard drive, from the early nineties, that was used in a store demo Mac in the UK (back then they were called Apple Centres). It worked, I moved it into another Mac, I used the wrong screw, and I popped the oscillator on the circuitboard. It had loads of demo software on it, all locked down with At Ease so that customers couldn't wreck it. I want to get it back!

The oscillator is a KDS 2M 24.000, which I guess is a 24MHz oscillator - but it appears to have 4 pins. I haven't seen a 4 pin oscillator before, and I can't find the part online at all. What part can I replace it with? Any suggestions?

(I have tried looking for a drive with the same controller board, an IBM WDS L80, but they're all selling for stupid money online.)

 

[Phipli]

I'm a menace and an idiot. I'm sorry, but it's true. I have a hard drive, from the early nineties, that was used in a store demo Mac in the UK (back then they were called Apple Centres). It worked, I moved it into another Mac, I used the wrong screw, and I popped the oscillator on the circuitboard. It had loads of demo software on it, all locked down with At Ease so that customers couldn't wreck it. I want to get it back!

The oscillator is a KDS 2M 24.000, which I guess is a 24MHz oscillator - but it appears to have 4 pins. I haven't seen a 4 pin oscillator before, and I can't find the part online at all. What part can I replace it with? Any suggestions?

(I have tried looking for a drive with the same controller board, an IBM WDS L80, but they're all selling for stupid money online.)

Do you have some photos please?

Where are you located approximately?

 

[Daniël]

Take off the oscillator entirely if you're able to. Then check which pins have traces running to them. It's not unlikely that only two pads are in use. Find a fitting oscillator of the right frequency, either four pin with the right orientation (check the datasheets), or a two pin that you can bodge between the two active pads.

EDIT: On an IBM DCHS drive with a similar 40MHz oscillator (same package), it appears the pinout is the same as this one for an Epson 32KHz oscillator:



Check if this is the same for yours. If so, getting a crystal between pin #1 and #4 is sufficient to get the drive going again, if you can't find one in this package. Doesn't need to be pretty, just functional.

 

[VMSZealot]

Take off the oscillator entirely if you're able to. Then check which pins have traces running to them. It's not unlikely that only two pads are in use. Find a fitting oscillator of the right frequency, either four pin with the right orientation (check the datasheets), or a two pin that you can bodge between the two active pads.

EDIT: On an IBM DCHS drive with a similar 40MHz oscillator (same package), it appears the pinout is the same as this one for an Epson 32KHz oscillator:

View attachment 61789

Check if this is the same for yours. If so, getting a crystal between pin #1 and #4 is sufficient to get the drive going again, if you can't find one in this package. Doesn't need to be pretty, just functional.

Thank you for this advice. I'll give it a go.

 

[bigmessowires]

I think this is more likely to be an oscillator with an integrated driver circuit, rather than a simple crystal in a 4-pin package. Something like this maybe: https://www.digikey.com/en/products/detail/txc-corporation/7W-24-000MAB-T/2354939 or this: https://www.ebay.com/itm/372849736653

With this kind of 4-pin oscillator, pin 1 is usually an enable input or NC, pin 2 is GND, pin 3 is the clock output and pin 4 is VCC.

 

[Phipli]

A photo would help.

 

[VMSZealot]

The popped oscillator is bottom right in the image, next to the power connector.

 

[VMSZealot]

I'll whip the logic board off when I get a moment, and get a shot of the underside.

 

[bigmessowires]

OK, I'm guessing that's a DSX151GS package, in which case @Daniël is correct it's just a simple crystal, but the pinout is different. See attached datasheet.

 

[VMSZealot]

Thank you - that's brilliant. I still can't see where to buy the matching part, but no matter. I'll find something compatible I hope.

And thank you for your work for the community. I have my floppy emulator next to me right now - and it's a brilliant piece of kit.