FRIED SCSI JACK PCB!

I think I fried my SCSI jack (the part that connects external devices). I say that because I have replaced the F09 fuse on my SCSI board, replaced the SCSI board with a new one and I still can't get my MPC to recognize a SCSI device. Just wanna know if there is another machine I can salvage one from, or if anybody has one they can spare or know of a suitable computer replacement.

I don't think there is really anything on the SCSI Jack PCB that can be fried, is there?

It doesn't really do much, except convert/interface the output of the SCSI/D IN PCB, from the connecting ribbon cable, to the external DB25 port.

Have you traced it out with a multimeter, to make sure all the circuits are intact?

Have you tried different SCSI devices, and are you sure those SCSI devices are working correctly?

Are you trying the SCSI devices with SCSI IDs other than 6, as that is what the MPC SCSI controller uses?

Are you terminating the end of the SCSI chain correctly?

Here are the SCSI Jack PCB and SCSI/D IN PCB schematics...

Well, the answer's no to the multimeter. I havent tried a different scsi device, but I know the one I'm using is functional because it works on my XL. Yes, I've tried scsi ID 5 and 6. I don't have any other devices connected, so scsi chain problems arent applicable. I wanted to get it serviced, but the repair man charges a $75 bench fee. He also said the complete repair (once I explained the symptoms) would be about $150. I would do it, but for what I paid for the 3K, it wouldn't make since to repair it because I could I'd end up spending just as much money as I would buying another 3K in better condition (which is what I'd rather do).

www.reneussance.com wrote:Well, the answer's no to the multimeter. I havent tried a different scsi device, but I know the one I'm using is functional because it works on my XL. Yes, I've tried scsi ID 5 and 6. I don't have any other devices connected, so scsi chain problems arent applicable. I wanted to get it serviced, but the repair man charges a $75 bench fee. He also said the complete repair (once I explained the symptoms) would be about $150. I would do it, but for what I paid for the 3K, it wouldn't make since to repair it because I could I'd end up spending just as much money as I would buying another 3K in better condition (which is what I'd rather do).

As long as the Zip is on SCSI ID 5, and termination on, I think it should work.

Have you tried formatting the Zip disk in the MPC3000?

I think you need a multimeter to check for SCSI fuse continuity and SCSI termination power, along with then tracing out the circuits to ensure they are continuous from their sources on the SCSI/D IN PCB through the circuits/connectors/cables and out to a bare DB 25 plug that is plugged into the external SCSI port.

That is what I would be trying.

It is a little hard without a multimeter to at least check continuity of fuse/circuits/connectors/cables/etc., and that the voltages are there and correct.

www.reneussance.com wrote:I have replaced the F09 fuse on my SCSI board, replaced the SCSI board with a new one and I still can't get my MPC to recognize a SCSI device.

You mean F901 fuse?

Someone else fixed (or maybe partly fixed?) a similar problem, by replacing a blown F2 power supply fuse, here...
viewtopic.php?f=4&t=161249&p=1520824&hilit=f901#p1520824

www.reneussance.com wrote:Just wanna know if there is another machine I can salvage one from, or if anybody has one they can spare or know of a suitable computer replacement.

Don't know, maybe the S-series rack mount samplers, one of the S3000 versions with SCSI, "might" use the same board, someone else would have to comment because I do not know.

You would not get one from a computer, as these PCBs are Akai PCBs, not general PC designs.

I tried formatting a zip disk and it keeps returning an error.

Here's where my problem started. Before I read the manual, I plugged an IDE zip into the scsi port WHILE THE DRIVE WAS ON! Yeah stupid I know. So maybe this will give a better understanding of what exactly is going on.

I don't know.

You say that you have tried a whole second MPC3000 SCSI/D IN PCB?

Where did that come from, and is it confirmed as being operational before you tried it?

Could be that a power supply fuse is blown, and that is preventing both SCSI/D IN PCBs from working?

Could be that the IDE Zip fried something deeper in the SCSI circuit or circuits it is connected to?

From this distance, and without you having a multimeter to at least do some basic tests to see if there is a continuous circuit from the external connector back to any active components, and that the SCSI terminating circuit is getting power, not sure how you can sort it out yourself.

Someone else will have to give you some ideas, good luck with it.

www.reneussance.com wrote: I wanted to get it serviced, but the repair man charges a $75 bench fee. He also said the complete repair (once I explained the symptoms) would be about $150. I would do it, but for what I paid for the 3K, it wouldn't make since to repair it because I could I'd end up spending just as much money as I would buying another 3K in better condition (which is what I'd rather do).

Please let me know where you can buy a MPC 3000 for $225.

www.reneussance.com wrote:Before I read the manual, I plugged an IDE zip into the scsi port WHILE THE DRIVE WAS ON!

The issue you have is not the fact you plugged the drive in when it was on.

The issue was that you plugged an Parallel Port device into a SCSI port. Your Parallel Port device will never work on a SCSI line.

The F901 fuse you replaced only protects the termination power line. Nothing else.

The problem should be contained within the SCSI board, although you may have also killed your 5V line in the process. You may have also destroyed the ferrites near the SCSI connector.

MPCHunter wrote:The problem should be contained within the SCSI board, although you may have also killed your 5V line in the process. You may have also destroyed the ferrites near the SCSI connector.

You can't test for any of this without a multimeter, and a little knowledge on how to use it.

I don't know if you have any hope of fixing this yourself.