Also in the original thread, we had discussed some voltage measurements taken at the external floppy drive connector on the SE/30. A member by the name of "tt" submitted the following...
SE/30 configuration: Daystar Turbo 040 @ 40Mhz, Asante MacCon, Daystar Adapter, 8 GB Baracuda HD, Sony stock unadjusted PSU, IIfx ROM, cleaned but not re-capped logic board, keyboard, mouse
Voltages:
Idle: 4.78V
HD floppy disk access: 4.78-4.74v
During warm boot from HD: 4.78-4.74v
Idle with HD spun-down: 4.80-4.79v
I posted my voltage values as follows...
SE/30 Cold Boot, Welcome to Macintosh screen, VOLTAGE READINGS:
1) Everything Installed: 4.83v
2) Everything but internal HD connected: 4.83v
3) Keyboard Removed: 4.84v
4) Keyboard & Internal Floppy Removed: 4.85v
5) Only MacCon Removed: 4.91v (keyboard and floppy still connected)
6) Keyboard connected with MacCon/TS Adapter/Daystar Removed = 5.09v
Based on the above, you can see the following is true:
1) IIgs Keyboard Voltage Drop when connected: 10mV
2) Internal SuperDrive Floppy Voltage Drop: 10mV
3) MacCon Voltage Drop: 80mV
4) Daystar Turbo 040 40MHz + TS Adapter Voltage Drop: 200mV
Another Voltage Observation:
Even with my SONY PSU cranked up to maximum voltage (via the variable resistor inside the PSU), I still only get 5.1v max output. I know my HD isn't dragging this voltage down because the HD is powered by another supply. And I tested to confirm that my secondary HD PSU in no way affects the voltage readings measured above. So then question then is, is 5.1v the maximum output of the SONY PSU? Obviously, I will need some of you to test this in order to compare.
And finally...
I conducted more tests in an effort to resolve my internal floppy drive issue. Sadly, I was not able to resolve it to my liking. As reported before, I cannot read/write 1.4MB HD floppies when a IIsi or IIfx ROM is installed along with the Daystar card; but I can read/write 800k & 400k disks just fine in the same configuration. With the Daystar installed and the stock SE/30 ROM installed, the HD floppies work fine. Again, I have reported all this before. Today, I removed the Daystar and tested with a IIsi ROM installed. HD floppies work fine!
What does this test prove? Well, we cannot simply say it is the Daystar card causing my floppy drive to flake out because HD floppies work fine with the Daystar card installed IF the stock SE/30 ROM is also installed. And we cannot simply say it is the result of using a non-stock ROM because I verified a IIsi ROM works IF the Daystar card is removed! So it appears to be a combination of things, BUT WHY?!?!
Another member by the name of "Tyler" posted that his voltages covered at close to 4.60v. I then replied to Tyler as follows...
Jag (from Jag's House) claims the "spec" says the SE/30 motherboard will work without crashes within plus/minus 0.5v from the nominal 5.0v level. I then asked Jag where he got the information and all he could say was "from memory." Not liking that answer, I posted here to see if others could post their voltages to compare. Now that two of us are showing fairly low voltages (and yet the computer works), it does give some credence to Jag's claim.
But let's assume Jag is correct. This means that anything below 4.50v will assuredly result in a system crash or other anomaly. In this case, it is very possible that some operation could result in a low voltage spike, just below 4.5v for a few milliseconds, resulting in a crash. This is especially true, I would think, on your machine, Tyler. Since you are showing only 4.6v.
On my machine, I measure 4.8v or so for a while, but as the machine is left on the PSU warms the the voltage drops. After about two hours, I starting measuring voltages as low as 4.70v at the external floppy connector. So you may wish to conduct the same experiment. I assume your voltage check was down at cold boot. That's good, but now leave the machine on and the DMM connected. Run Norton or some speed check utility and check the voltage level at regular intervals. If your machine is like mine, as the PSU warms the voltage will drop. I would be curious to hear how low your voltage can get without a crash.
By the way, my Sony PSU in the SE/30 had its voltage adjusted up to max, and yet I was still measuring those rather low voltages.
SE/30 configuration: Daystar Turbo 040 @ 40Mhz, Asante MacCon, Daystar Adapter, 8 GB Baracuda HD, Sony stock unadjusted PSU, IIfx ROM, cleaned but not re-capped logic board, keyboard, mouse
Voltages:
Idle: 4.78V
HD floppy disk access: 4.78-4.74v
During warm boot from HD: 4.78-4.74v
Idle with HD spun-down: 4.80-4.79v
I posted my voltage values as follows...
SE/30 Cold Boot, Welcome to Macintosh screen, VOLTAGE READINGS:
1) Everything Installed: 4.83v
2) Everything but internal HD connected: 4.83v
3) Keyboard Removed: 4.84v
4) Keyboard & Internal Floppy Removed: 4.85v
5) Only MacCon Removed: 4.91v (keyboard and floppy still connected)
6) Keyboard connected with MacCon/TS Adapter/Daystar Removed = 5.09v
Based on the above, you can see the following is true:
1) IIgs Keyboard Voltage Drop when connected: 10mV
2) Internal SuperDrive Floppy Voltage Drop: 10mV
3) MacCon Voltage Drop: 80mV
4) Daystar Turbo 040 40MHz + TS Adapter Voltage Drop: 200mV
Another Voltage Observation:
Even with my SONY PSU cranked up to maximum voltage (via the variable resistor inside the PSU), I still only get 5.1v max output. I know my HD isn't dragging this voltage down because the HD is powered by another supply. And I tested to confirm that my secondary HD PSU in no way affects the voltage readings measured above. So then question then is, is 5.1v the maximum output of the SONY PSU? Obviously, I will need some of you to test this in order to compare.
And finally...
I conducted more tests in an effort to resolve my internal floppy drive issue. Sadly, I was not able to resolve it to my liking. As reported before, I cannot read/write 1.4MB HD floppies when a IIsi or IIfx ROM is installed along with the Daystar card; but I can read/write 800k & 400k disks just fine in the same configuration. With the Daystar installed and the stock SE/30 ROM installed, the HD floppies work fine. Again, I have reported all this before. Today, I removed the Daystar and tested with a IIsi ROM installed. HD floppies work fine!
What does this test prove? Well, we cannot simply say it is the Daystar card causing my floppy drive to flake out because HD floppies work fine with the Daystar card installed IF the stock SE/30 ROM is also installed. And we cannot simply say it is the result of using a non-stock ROM because I verified a IIsi ROM works IF the Daystar card is removed! So it appears to be a combination of things, BUT WHY?!?!
Another member by the name of "Tyler" posted that his voltages covered at close to 4.60v. I then replied to Tyler as follows...
Jag (from Jag's House) claims the "spec" says the SE/30 motherboard will work without crashes within plus/minus 0.5v from the nominal 5.0v level. I then asked Jag where he got the information and all he could say was "from memory." Not liking that answer, I posted here to see if others could post their voltages to compare. Now that two of us are showing fairly low voltages (and yet the computer works), it does give some credence to Jag's claim.
But let's assume Jag is correct. This means that anything below 4.50v will assuredly result in a system crash or other anomaly. In this case, it is very possible that some operation could result in a low voltage spike, just below 4.5v for a few milliseconds, resulting in a crash. This is especially true, I would think, on your machine, Tyler. Since you are showing only 4.6v.
On my machine, I measure 4.8v or so for a while, but as the machine is left on the PSU warms the the voltage drops. After about two hours, I starting measuring voltages as low as 4.70v at the external floppy connector. So you may wish to conduct the same experiment. I assume your voltage check was down at cold boot. That's good, but now leave the machine on and the DMM connected. Run Norton or some speed check utility and check the voltage level at regular intervals. If your machine is like mine, as the PSU warms the voltage will drop. I would be curious to hear how low your voltage can get without a crash.
By the way, my Sony PSU in the SE/30 had its voltage adjusted up to max, and yet I was still measuring those rather low voltages.