Those are polyfuses. they are supposed to blow, and self-reset.
-
Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.
One more SE/30 saved ! But strange HDD behavior
- Thread starter Ozymandias
- Start date
would you believe I worked in Boruns electronics in mahon, cork , Ireland, and we made trimpots, network resistors and those fuses.
I never knew at the time that the network resistors were in macs or the polyfuses. I don't know if the polyfuses in the macs were from boruns though
-
the brother worked up in apple in hollyhill in cork as well........he was in debug. He told me his job was debugging the se/30 that were just built. He brought me in there on a tour of the factory
Still cant forget the pick and place machine building the boards....the speed of the thing......the solder bath...........
I remember the place being so white...clean.......looked like a great place to work. Last time he was down I showed him and se30 board and after 20/30 years he could tell me what each chip did......was well impressed
-
he said to keep and eye out on the boards I have for the initals POK. He said that every time he fixed a board he signed it.
-
and here I am 20/30 years later a complete mac head...............funny the way things happen!!
I never knew at the time that the network resistors were in macs or the polyfuses. I don't know if the polyfuses in the macs were from boruns though
-
the brother worked up in apple in hollyhill in cork as well........he was in debug. He told me his job was debugging the se/30 that were just built. He brought me in there on a tour of the factory
Still cant forget the pick and place machine building the boards....the speed of the thing......the solder bath...........
I remember the place being so white...clean.......looked like a great place to work. Last time he was down I showed him and se30 board and after 20/30 years he could tell me what each chip did......was well impressed
-
he said to keep and eye out on the boards I have for the initals POK. He said that every time he fixed a board he signed it.
-
and here I am 20/30 years later a complete mac head...............funny the way things happen!!
Last edited by a moderator:
I remember before 9/11 meeting a guy from that area who also worked for Apple, Falen. He commented how he loved the 5300ce (which I had out at Barnes & Noble Coffee Shop at the time) and that he used to build them and other laptops along the line. But between food and family, he could never afford to get one until after he moved to the states.
Last edited by a moderator:
Ha! So was I to some extent. People remember me as the first one in the 'hood to own a computer!
But like you said, lets not hijack... So...
TechKnight - I knew there was mention of the SCSI Fuse somewhere. But it is on the Mac II, which the SE30 came out sometime later and uses the same fuse. See Page 233 of Dead Mac Scrolls. What is funny is Page 177, where the same problem is for the SE & SE\30 but references the SCSI Chip as the problem, it says "Also see prior entry" but there is none for the SCSI Problem. On Page 234, where is references the problem as the SCSI Chip for the Mac II also says "Also see prior entry" where the fuse is referenced. So the page for the fuse on the SE & SE\30 is missing.
I remember this because I've repaired a few of those fuses by replacing them. If they are polyfuses that self-repair, they must have gotten such a surge that they were blown to Hades!
Ozymandias - got the SCSI Chip yet? I want to see this mad puppy howling.
But like you said, lets not hijack... So...
TechKnight - I knew there was mention of the SCSI Fuse somewhere. But it is on the Mac II, which the SE30 came out sometime later and uses the same fuse. See Page 233 of Dead Mac Scrolls. What is funny is Page 177, where the same problem is for the SE & SE\30 but references the SCSI Chip as the problem, it says "Also see prior entry" but there is none for the SCSI Problem. On Page 234, where is references the problem as the SCSI Chip for the Mac II also says "Also see prior entry" where the fuse is referenced. So the page for the fuse on the SE & SE\30 is missing.
I remember this because I've repaired a few of those fuses by replacing them. If they are polyfuses that self-repair, they must have gotten such a surge that they were blown to Hades!
Ozymandias - got the SCSI Chip yet? I want to see this mad puppy howling.
polyfuses will open up permanently if the current flowing through far exceeds the maximum rating, itll blow the reed apart.
Last edited by a moderator:
Back again everyone,
I received the new chip today and soldered it. Then I checked all the connections again just to be sure.
First try using the new HDD I bought, it did the exact same thing as before.
Then I tried with the old HDD and it started several times.
The system boots up after exactly 25 sec each time, don't know of its normal.
Could it be a jumper config issue with the new Disk? What should be the jumpers config on the SCA to CSI 50 pins adaptor to match this one:
I received the new chip today and soldered it. Then I checked all the connections again just to be sure.
First try using the new HDD I bought, it did the exact same thing as before.
Then I tried with the old HDD and it started several times.
The system boots up after exactly 25 sec each time, don't know of its normal.
Could it be a jumper config issue with the new Disk? What should be the jumpers config on the SCA to CSI 50 pins adaptor to match this one:
Booting on a Mac takes time. I noticed that on my systems with a SSD, that there is a 20 second or so pause between the "Welcome to Mac" sign and the first extension loading. And some extensions also take time to load up as well.
What system are you loading? And what type of drive is on the pic above? It looks like it is on SCSI Address 6 which should not be a problem but it takes a few seconds for the mac to find it as it counts up the scsi id's to find a drive. If you remove the jumpers on A1 and A2, the Mac should find it faster.
Another question - is the system folder on that drive blessed?
What system are you loading? And what type of drive is on the pic above? It looks like it is on SCSI Address 6 which should not be a problem but it takes a few seconds for the mac to find it as it counts up the scsi id's to find a drive. If you remove the jumpers on A1 and A2, the Mac should find it faster.
Another question - is the system folder on that drive blessed?
The picture above is of the old but still working 1990 70MB Quantum drive that came with the mac.
I removed the A1 A2 jumpers on it and it indeed started loading System 7.5.5 instantly.
I removed the A1 A2 jumpers on it and it indeed started loading System 7.5.5 instantly.
When the Mac (any SCSI Mac and PCs with SCSI too), the SCSI chip tests each address (0 - 6) for a boot device, with each test about 3 to 5 seconds long. So to get to A6 (jumpers A1 and A2 adding up to A6 in binary), it takes about 18 to 30 seconds. While going to A0 (the first address in the binary chain), goes right there immediately.
I need your help because the new drive I bought still isn't working.
Here is what I get from Apple Personal Diagnostics with the old (above) and the new (below) drives:
No name found for the new one.
Any ideas ?
Here is what I get from Apple Personal Diagnostics with the old (above) and the new (below) drives:
No name found for the new one.
Any ideas ?
It is detecting the drives. I dont see what the problem is?
the IBM drive may need formatted. Also, you will need to change its SCSI ID back to 0, but that wouldnt stop the drive from mounting IF... its formatted correctly.
the IBM drive may need formatted. Also, you will need to change its SCSI ID back to 0, but that wouldnt stop the drive from mounting IF... its formatted correctly.
