Okay, here's a strange one...

[phreakout]

I am working on an SE/30 logic board. I've got it recapped and is showing normal operation symptoms. But when I connect an internal SCSI hard drive, it displays just the mouse cursor and a light gray background. When I disconnect the SCSI data cable (between the drive and the logic board), it will then advance to showing the obvious "floppy disk with blinking question mark", which is normal. To summon it up, normal booting only occurs all the time when I have the internal hard drive disconnected, but success with internal drive connected will occur maybe 1 or 2 in 5 tries. I haven't tried the external SCSI port yet, so I'll have to post back with my results.

I checked out here(#10), but I doubt that the SCSI chip is bad. I was wondering if it may be one of the Bourns network filters, like RP3 maybe? Anyone out there have the same problem on any 68k Mac?

Your thoughts are greatly appreciated.

73s de Phreakout. :rambo:

 

[Scott Baret]

First thought--have you tried another hard drive? I've had Macs hang on that screen for a while if the drive is bad, yet not bad enough the Mac can't attempt to access them. This seems to be extremely common with MiniScribes in particular (I've had two in the past year alone do this to me). What kind of drive are you using?

Second thought--have you tried that drive in another Mac? This could narrow the problem down a bit, especially if you have an external drive to try (or any external SCSI drive; if you have the driver and can run it from a floppy it would be a good way to test). Note that an SE/30 can't boot from a CD.

 

[phreakout]

The hard drive is a 700MB Quantum brand using an Apple driver. The only bad thing about the drive is the occasional stiction, then I just slap the side to get it working again. I'll try a different hard drive to see if the problem still occurs. I'll also check the external SCSI port tomorrow as well.

73s de Phreakout. :rambo:

 

[techknight]

those older quantums will take a beating. I had 4.3gb quantum vikings seize up from sticktion, i took them apart and cleaned the goo off the platters on all the drives, back in 2004.

They still work today. no bad sectors, only issue i ran into was one of them was dying from bad berrings. but all the others still work.

 

[Unknown_K]

Goo on the platters would be bearing grease? The only time I ever found anything on the platters of a drive I took apart was metal/magnetic dust from a head crash.

 

[techknight]

Well if sticky goo counts as berring grease. then it might have been. but regardless, nasty stuff for the head to get stuck in. surprisingly, it didnt damage the head or platter enough to cause an issue. But the drives came out of a server, that one of the backplane fans failed. so that was probably the cause of it all....

 

[phreakout]

Luckily for me, this isn't a stiction problem; more or less a communications problem. I'm still working on it, so I'll post more results of what I find in a bit.

73s de Phreakout. :rambo:

 

[overdriver]

have you checked the SCSI ID conflict possibility?

It could be SCSI termination problem or SCSI cable itself could be bad.

 

[phreakout]

I did swap the cable, thinking it was bad, and it finally worked, but only for a couple of reboots. Haven't had a chance yet to check it out further, since I'm at work. But I'll get to it later today.

73s de Phreakout. :rambo:

 

[phreakout]

Okay, I don't know what's going on. But now it's working fine. I hooked up an external hard drive, is recognized and mounts on the desktop; plus I can read and write to the drive fine. The internal drive was swapped with another known good drive and it too is recognized, mounts and read/write to disk fine. I'm thinking it was a bad cable or something in the ROM SIMM was screwing up the SCSI or logic board. I also tried operating both with and without a battery in place. I can't get it to fail, like it did in the past week. Really weird.

Thank you everyone for your suggestions. In the mean time, I'll tell the owner to keep a close eye out in case this happens again and report it to me.

73s de Phreakout. :rambo:

 

[trag]

Okay, I don't know what's going on. But now it's working fine. I hooked up an external hard drive, is recognized and mounts on the desktop; plus I can read and write to the drive fine. The internal drive was swapped with another known good drive and it too is recognized, mounts and read/write to disk fine.

Have you checked for bad/old solder joints on the internal SCSI connector header? I could see a pin on the cable header going from not-connected to connected as you swap the cables in and out. It's kind of far fetched though.

 

[phreakout]

I'll take a look at it. I had the board running fine all of yesterday and couldn't dupe the problem. I'm still leaning on possibly a bad data cable. I found that the two I tried gave the same symptoms and a third one got it working finally.

73s de Phreakout. :rambo:

 

[phreakout]

Okay, I spoke too soon. It's happening again. If I have the internal hard drive connected up, the only way I can boot is to insert a floppy and do Cmd + Option + Shift + Delete. The floppy will boot as far as "Welcome to Macintosh" and then just sit there doing nothing.

If I disconnect the hard drive, it will boot from a floppy like normal, without Cmd + Option + Shift + Delete.

It doesn't matter if I swap internal hard drives or have external SCSI hard drives hooked up, it will still produce the same initial symptom of this (#10). The only way it will boot normal is if I disconnect the internal HDD and use a floppy. I still think it has something to do with the SCSI controller ship or maybe one of the Bourns network filters, probably RP3.

73s de Phreakout. :rambo:

 

[H3NRY]

Just to state the obvious (which is easy to overlook) the internal HD may be loading the power supply too much to boot. Old power supplies' voltage can drift and then the Mac is very screwy. Old drives can also throw an error when booting which Apple's ROM routines aren't good at recovering from, though the SE was not the worst offender in that regard. Let us know what you find.

 

[phreakout]

I did try hooking up the hard drive to a separate power supply, but I get the same results. So I am ruling out the internal power supply. I'm going to try replacing RP3 (Bourns Network Filter), and if that doesn't work, it has got to be the 53C80 SCSI Controller Chip (UI12). I'm trying to find any vendor that will sell me these replacement parts individually, and not in bulk; Digikey can get it, but I have to buy a minimum of 175 @ $2.00 each. I just don't have that kind of cash and I don't need 175 of 'em either, just 1.

I'll be working on it this week, trying to wrap it up, so I'll keep you posted.

73s de Phreakout. :rambo:

 

[Scott Baret]

H3NRY mentions power supplies. SEs came with either an Astec or Sony power supply. As with the IIcx and IIci, which can also have a GE, the Astec is the inferior of the two, having issues both when the machines were new and especially today. I have not encountered a fully functional Astec power supply in 15 years. They weren't as common as the Sony, so this could be one reason, but the reliability is a huge factor as well. Even the Macintosh Bible, Fourth Edition cautioned against purchasing a used SE with an Astec supply. I'd rate them in the same category as the original beige-switched 128K/512K/Plus power supplies in terms of reliability.

There's an easy way to tell the difference between the two brands. The rocker switch on an Astec is white, while Sonys sport a black switch.

If you are lucky enough to have a working Astec supply, be warned about problems with voltages drifting (as H3NRY indicated). If you happen to have an extra power brick, you may want to swap it just to rule another component out. The SE, SE SuperDrive/FDHD, and SE/30 all use the same power supply type.