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DB25 BlueSCSI died!
Posted by: ExplorerZ on 2023-03-06 05:22:46
Right after fixing one of my SEs, my only BlueSCSI died. Don't know what happened, but when tested on both of my working macs the lights don't come on and it does nothing. Tried using the usb port to power it but also nothing. I think I broke it by plugging it into my SE while running. Is it fixable or should I buy a new one?
Posted by: 3lectr1cPPC on 2023-03-06 05:49:39
These have known issues with termination that case the microcontroller to become overloaded. It usually doesn’t kill them but it’s always possible that something happened and it just died. Probably best to get one of the improved V2 models, or a ZuluSCSI. Both are much higher quality.
Posted by: Phipli on 2023-03-06 05:52:51
Right after fixing one of my SEs, my only BlueSCSI died. Don't know what happened, but when tested on both of my working macs the lights don't come on and it does nothing. Tried using the usb port to power it but also nothing. I think I broke it by plugging it into my SE while running. Is it fixable or should I buy a new one?
Putting the BlueSCSI to one side, do not hot plug connectors on vintage computers. Very few things were designed for hot plugging. Serial is the only thing you can hot plug on the back of an old Mac (if that), and hot swapping can blow chips on the board. Be patient and power down, switch the plugs, power up.

BlueSCSI wise? You're lucky it was the BlueSCSI and not the mac as they're much cheaper to replace. BlueSCSIs do that, they're not long lasting, especially if mistreated.

If you're able, I recommend replacing it with a ZuluSCSI. They are more expensive, but also a better, more resilient and long lasting, design.
Posted by: Paralel on 2023-03-06 06:26:37
From what I know, it has a fuse, it probably was blown. I don't know where its located or if it can be replaced.
Posted by: Phipli on 2023-03-06 07:25:52
From what I know, it has a fuse, it probably was blown. I don't know where its located or if it can be replaced.
If this is what they look like, They don't have a fuse on the SCSI circuit :
Posted by: ExplorerZ on 2023-03-06 11:33:11
If this is what they look like, They don't have a fuse on the SCSI circuit :


Thats what i have
Posted by: Paralel on 2023-03-06 11:33:17
I wonder if its internal to the microcontroller? I could also have misunderstood what someone mentioned.
Posted by: Phipli on 2023-03-06 11:36:45
I wonder if its internal to the microcontroller? I could also have misunderstood what someone mentioned.
But a fuse blown in a microcontroller wouldn't be any use, because if you had to replace the microcontroller to replace the fuse then there is no purpose in having the fuse?

I suspect there might be polyfuses on the USB port and that is what your friend meant?

They wouldn't come into play in this instance.
Posted by: Paralel on 2023-03-06 11:45:44
But a fuse blown in a microcontroller wouldn't be any use, because if you had to replace the microcontroller to replace the fuse then there is no purpose in having the fuse?

I suspect there might be polyfuses on the USB port and that is what your friend meant?

They wouldn't come into play in this instance.

I remember they said that whatever type of fuse it is was meant so that the BlueSCSI always died rather than allow any inappropriate electric excursion into the system. So, in that context, if it is inside the microcontroller, and it stops the machine from being damaged, it's doing its job. However, if the fuse gets blown and the machine wasn't at risk then it just sorta sucks since your BlueSCSI is dead. I guess the safety would be worthwhile even if a false positive is possible.
Posted by: Phipli on 2023-03-06 11:49:42
I remember they said that whatever type of fuse it is was meant so that the BlueSCSI always died rather than allow any inappropriate electric excursion into the system. So, in that context, if it is inside the microcontroller, and it stops the machine from being damaged, it's doing its job. However, if the fuse gets blown and the machine wasn't at risk then it just sorta sucks since your BlueSCSI is dead. I guess the safety would be worthwhile even if a false positive is possible.
That circuit isn't designed to intentionally fail before the computer. But it is a blessing that they do.
Posted by: avadondragon on 2023-03-06 21:53:02
SMT32 boards are super super cheap just grab another and slap it on there.
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