Apple Tape Back Up 40SC Not Working

[MacintoshMan1999]

I've recently gotten an Apple Tape Back Up 40SC off of eBay that isn't working, The power light was on in the photos but now it's not.

I've tested the two LED's and fan and can confirm they're working.

Could I have some advice?

 

[LaPorta]

By “not working” you mean…

It does nothing?

It is recognized by the computer but does nothing?

It tried to function but won’t read/write a tape properly?

 

[MacintoshMan1999]

The Power supply seems to not work, I've verified that power is getting to the board by checking the voltage across the fuse, other places on the board have power also but it's not getting to the connector.

 

[Byrd]

It's often the PSU in these external Apple drives (optical, tape, HD) - crack it open and see how damaged it looks, replace caps if OK, otherwise look into a modern replacement to fit inside the existing case.

 

[MacintoshMan1999]

It Looks fine but there are some wiggly components, 3 capacitors and a large resistor. One capacitor is a solid plastic block (Last picture, being pointed at with screwdriver)

Here are some pictures of the PSU:

 

[Iesca]

"Wiggly" components are fine, if what you mean is that they bend over when you press on them, not so much if they're actually loose from their solder joints.

At first glance, the two caps on the daughter board are definitely dead, what with the leaked capacitor fluid. As has been said already, you may want to begin with just re-capping the whole thing, and then going from there.

 

[MacintoshMan1999]

"Wiggly" components are fine, if what you mean is that they bend when you press on them, not so much if they're actually loose from their solder joints.

At first glance, the two caps on the daughter board are definitely dead, what with the leaked capacitor fluid. As has been said already, you may want to begin with just re-capping the whole thing, and then going from there.

Since the PSU is identical to the HD20SC I'm going to use a video by JDW on his.

 

[MacintoshMan1999]

While disordering the Capacitors i found this resistor...

 

[MacintoshMan1999]

I put the resistors color coding through a calculator, its a 3.3 Ohm with a 5% tolerance.
Ive been looking on mouser and can't seem to find a replacement, could I have a little help please?

 

[Iesca]

Here's a page of results from DigiKey that matches your specifications (I included both 1/4 and 1/2 Watt resistors).

https://www.digikey.com/short/tpj25v5v

That said, it looks mostly dirty, I would be kind of surprised if it wasn't still working. Did you measure its resistance after you removed it?

 

[MacintoshMan1999]

Here's a page of results from DigiKey that matches your specifications (I included both 1/4 and 1/2 Watt resistors).

https://www.digikey.com/short/tpj25v5v

That said, it looks mostly dirty, I would be kind of surprised if it wasn't still working. Did you measure its resistance after you removed it?

No, I did not. There was a chip in it, so it probably needs replaced anyway.

 

[MacintoshMan1999]

Turns on now, I'm going to hook it up to my SE.

 

[luRaichu]

I put the resistors color coding through a calculator, its a 3.3 Ohm with a 5% tolerance.
Ive been looking on mouser and can't seem to find a replacement, could I have a little help please?

In my experience Mouser isn't very good for finding specific parts. In the future you might want to use DigiKey for that instead.

Turns on now, I'm going to hook it up to my SE.

Cool! I'd like to see a video of it working.

 

[MacintoshMan1999]

The activity light is flashing and the computer is giving me this message:

 

[Iesca]

It could be that the power supply was able to be resurrected just enough to power "on" the device, but when sent commands and putting the device under load it's not able to draw enough power. There could of course be something else entirely that is wrong with it as well.

 

[MacintoshMan1999]

It could be that the power supply was able to be resurrected just enough to power "on" the device, but when sent commands and putting the device under load it's not able to draw enough power. There could of course be something else entirely that is wrong with it as well.

A rubber wheel that's supposed to move the tape in the cartridge has no grip, its hard and smooth.

The tape isn't moving so I guess the drive can't find the BOT...

 

[stepleton]

A pretty classic problem. At least the wheel hasn't done the other thing they sometimes do, which is turn back into petroleum.

An IBM 5100 in my collection has a gripless wheel like yours: on that machine, I can press the tape cartridge firmly in the drive and force better traction. If I were less lazy, then I'd do what YouTubers like CuriousMarc and Jerry Walker do, which is replace the wheel. For his HP tape cartridge drive, Marc knows a certain kind of rubber tube IIRC that he can cut into rings that serve as replacements; he might also paint on some kind of rubber goo that widens the wheel and dries to something grabbier. Walker also starts with a rubber tube, but I think he fits it onto the post and then machines it down to the correct size in a lathe. This may yield a rougher, grabbier surface.

Good luck!

 

[MacintoshMan1999]

A pretty classic problem. At least the wheel hasn't done the other thing they sometimes do, which is turn back into petroleum.

An IBM 5100 in my collection has a gripless wheel like yours: on that machine, I can press the tape cartridge firmly in the drive and force better traction. If I were less lazy, then I'd do what YouTubers like CuriousMarc and Jerry Walker do, which is replace the wheel. For his HP tape cartridge drive, Marc knows a certain kind of rubber tube IIRC that he can cut into rings that serve as replacements; he might also paint on some kind of rubber goo that widens the wheel and dries to something grabbier. Walker also starts with a rubber tube, but I think he fits it onto the post and then machines it down to the correct size in a lathe. This may yield a rougher, grabbier surface.

Good luck!

Thanks!

 

[MacintoshMan1999]

A pretty classic problem. At least the wheel hasn't done the other thing they sometimes do, which is turn back into petroleum.

An IBM 5100 in my collection has a gripless wheel like yours: on that machine, I can press the tape cartridge firmly in the drive and force better traction. If I were less lazy, then I'd do what YouTubers like CuriousMarc and Jerry Walker do, which is replace the wheel. For his HP tape cartridge drive, Marc knows a certain kind of rubber tube IIRC that he can cut into rings that serve as replacements; he might also paint on some kind of rubber goo that widens the wheel and dries to something grabbier. Walker also starts with a rubber tube, but I think he fits it onto the post and then machines it down to the correct size in a lathe. This may yield a rougher, grabbier surface.

Good luck!

Turns out the wheel is just metal, I've looked at the apple cartridges for this and they seem to have a deeper cutout than my cartridges.

I'm going to Dremel out some plastic and see if it solves anything...