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SE/30 SCSI Not Detected

SuperSVGA

Well-known member
I have an SE/30 that works great, except I can't get it to detect the internal SCSI hard drive.

Booting from a 7.0.1 Disk Tools disk, I can run HD SC Setup but it tells me that no suitable SCSI devices were found.

The drive spins up fine, but the activity light never blinks. I tried pulling a working 42 S drive from a Classic II, but it does the exact same thing as the 80 S originally in the SE/30.

I thought the issue might be the caps, so I did a full recap of the logic board using the following:

1x 1uf 50v Radial Electrolytic

1x 220uf 16v Axial Electrolytic

1x 470uf 50v Axial Electrolytic

10x 47uf 16v Radial Non-Polarized Electrolytic

I used SMD291 in removing the SMD Electrolytic caps and in replacing them.

I also replaced the PRAM battery.

Once everything was back together, I flipped the switch and... exact same issue. Except the sound works now. I forgot it was even broken.

So I'm pretty much back in the same spot. There's always a chance I did something wrong, since this is the first recap I've ever done.

At what points could the issue be?

 

BadGoldEagle

Well-known member
Good thing you recapped that logic board. It had to be done anyway. Since you're new around here (and by the way, welcome!), I take the opportunity to warn you about the Maxell "Bomb". Some 3.6V ½ AA batteries explode and boards which suffered from them are usually beyond repair. So, if you haven't already done so, I advise you to remove the battery now. The Mac will run fine without it. You can buy a replacement if you want.

Back to the SCSI issue... Here are a few suggestions: 

- Wash the board if you haven't already done so. Some old cap goo might still be bridging contacts. I usually wash my boards before I recap them (after I remove the old, perished caps), but you should still be able to wash it after you put the new ones on. Take a large bucket, fill it with hot tap water, add some washing-up liquid, mix and immerge your board. Get an old toothbrush and gently scrub the board. After that, rinse it with clear water and dry it immediately (otherwise it'll rust!). I use a hair dryer for that. Dry it really well. You don't want to fry any components after you put it back in the /30.

- Have you tried a different SCSI cable? Did you keep the cable from the Classic II? Sometimes cables die or aren't the appropriate ones, I've seen that happen before.

- I would have told you to use another piece of software (for example Lido. It works a lot better than Apple's HD Setup, especially on non Apple drives), but since your known working drive doesn't work in the /30, it's probably not a formatting issue.

If none of the above work, then you probably have a bad SCSI chip or blown fuse... This can happen if, for example, the previous owner plugged in a parallel device to the SCSI port. You can still buy NOS ones without cannibalising a dead Mac, I think...

Edit: Yes, you can still buy ones on ebay...

https://www.ebay.com/itm/QTY-1x-NCR-53C80-609-3400257-SCSI-Interface-Controller-PLCC-/140919602890?_trksid=p2349526.m4383.l4275.c4

https://www.ebay.com/itm/1pcs-AM53C80AJC-BULK-AM53C80-PLCC44-AMD/263277308606?hash=item3d4c8ceabe:g:7bUAAOSw7z1Z7gzf

 
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Bolle

Well-known member
Check the term-power fuse next to the SCSI port first. It can blow easily when devices are attached or detached while the machine is running.

I had a board that would only see SCSI devices on the internal connector when a terminator was plugged into the external port. This resulted from a blown fuse as well.

 

techknight

Well-known member
the 3 caps leak really bad by the molex connector. More times than not, it takes out a connection or two to the SCSI IC. Known problem. Youll need to buzz them out against the schematic, and run patch-wires. 

 
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SuperSVGA

Well-known member
Since you're new around here (and by the way, welcome!), I take the opportunity to warn you about the Maxell "Bomb". Some 3.6V ½ AA batteries explode and boards which suffered from them are usually beyond repair. So, if you haven't already done so, I advise you to remove the battery now. The Mac will run fine without it. You can buy a replacement if you want.
It had a Tandiran battery in it when I got it (looks like it's dated 1990), and I replaced it with a Tenergy battery (the only thing I could find at Fry's, almost missed it too. Hopefully it's not as bad as the Maxell battery, but I was considering some way to get it further away from the board or protect it.

Wash the board if you haven't already done so.
I sprayed it pretty well with electrical contact cleaner spray, I'm not sure if that quite did the job though. Maybe I'll try fully washing it.

Have you tried a different SCSI cable? Did you keep the cable from the Classic II?
I went back and pulled the SCSI cable from the Classic II today, didn't solve the problem unfortunately.

I would have told you to use another piece of software (for example Lido. It works a lot better than Apple's HD Setup, especially on non Apple drives), but since your known working drive doesn't work in the /30, it's probably not a formatting issue.
Yep, I tried Lido, it doesn't give any errors but it doesn't detect any drives.

If none of the above work, then you probably have a bad SCSI chip or blown fuse... This can happen if, for example, the previous owner plugged in a parallel device to the SCSI port. You can still buy NOS ones without cannibalising a dead Mac, I think...
Hmm, I might try that if I don't have luck with anything else. I'll probably try to order a rework station first, probably a bit easier than my heat gun.

Check the term-power fuse next to the SCSI port first. It can blow easily when devices are attached or detached while the machine is running.

I had a board that would only see SCSI devices on the internal connector when a terminator was plugged into the external port. This resulted from a blown fuse as well.
The fuses are F1, F2, and F3 right? They aren't like any fuses I've ever seen. I checked them with a multimeter in resistance mode (my multimeter with continuity mode needs new batteries) and all the fuses seemed fine.

the 3 caps leak really bad by the molex connector. More times than not, it takes out a connection or two to the SCSI IC. Known problem. Youll need to buzz them out against the schematic, and run patch-wires.
Hmm. That's an idea. I'll have to see if I can make sense of these schematics I found online.

 

SuperSVGA

Well-known member
So I gave a good washing, but it didn't seem to do any good. Actually I thought I ruined it at first, since I was getting simasimac when I booted it up, but then I found some unseated RAM when I opened it back up (and then more the second time I opened it back up).

I ordered a replacement SCSI chip that should be here by the end of the week, just in case that's the issue.

Can anyone help me a little with testing connections against the schematic? I've looked over the BOMARC and the Apple versions of the schematic and tried testing a few points, but I guess I'm having trouble making sense of the schematics.

 
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