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AST 386SX laptop will not boot from floppy disk

I

itsvince725

Experienced Member
Joined
Nov 26, 2016
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446
Location
Pennsylvania
I have an AST Premium Exec 386SX/20 laptop with a faulty old Conner CP2044PK hard drive that no longer boots. However, trying to boot from a MS-DOS 6.22 floppy disk is not working. The floppy drive does not seek and when I boot the system with a disk in the drive and run Setup to set the date and time and all that, I get this screen every time and there is seemingly no way past it.

https://i.imgur.com/nq4LKDO.jpg

I have also tried to boot the computer with the hard drive disconnected and a disk in the drive but I had the exact same issue. Is my floppy drive dead or is there some other weird issue at hand here, like the fact that I don't have a CMOS battery?
 
No CMOS battery means the machine has no clue to it's own configuration. Fix that before trying anything else.
 
T-R-A said:
No CMOS battery means the machine has no clue to it's own configuration. Fix that before trying anything else.
Click to expand...

When I run the configuration utility and save the settings it just immediately goes back to that screen pictured above. If I run the configuration utility again my changes are still saved, as are the date and time, but it's just an infinite loop of booting to a hard drive error and being asked to run the setup utility.
 
Still, you need that battery to save between reboots. Shouldn't be a real problem unless it's an old Dallas module.
 
T-R-A said:
Still, you need that battery to save between reboots. Shouldn't be a real problem unless it's an old Dallas module.
Click to expand...

It is (or rather, was, I had to throw it out because it was leaking), a trio of NiCad cells solder-tabbed together attached to a red and black wire and a tiny connector that plugs into the motherboard of the laptop.
 
I don't know if I would actually NEED NiCad cells or if I could use some kind of CR2032 battery holder, perhaps with a resistor added to stop it trying to charge the CR2032.
 
Not a resistor; you'd need a blocking diode. Personally, unless there's something wrong with the charging circuit, I'd stick to the design the machine originally had. But then, of course, it's not my laptop.
 
I mean, I really, really am too nervous to solder to battery cells so I'd either have to find a way around that or pay someone else to build me a battery that way.
 
itsvince725 said:
It is (or rather, was, I had to throw it out because it was leaking), a trio of NiCad cells solder-tabbed together attached to a red and black wire and a tiny connector that plugs into the motherboard of the laptop.
Click to expand...
So, it was a 3.6V NiCad battery (3 cells of 1.2V). Per [here], for the 'CMOS' battery application, NiMH can substitute NiCad. So, a 3.6V NiMH battery, with the required connector, will work.

Searching the internet, 3.6V NiMH batteries with connectors are common. Maybe there is one that is appropriately sized for the laptop and has the required connector.

itsvince725 said:
I mean, I really, really am too nervous to solder to battery cells so I'd either have to find a way around that or pay someone else to build me a battery that way.
Click to expand...
If you cannot find one with the required connector, maybe you buy one with a different connector, then solder on the connector (with a length of its wires) from the old battery.
 
Yeah, adapting an existing battery is something I'd feel comfortable doing, but not building a battery from scratch. People who rebuild laptop batteries out of loose 18650s and solder tabs onto them have more courage in one hand than I've got in my whole body.
 
People who rebuild laptop batteries out of loose 18650s and solder tabs onto them have more courage in one hand than I've got in my whole body.
Click to expand...

Not that big a deal. There's lots of "tricks" available (tacky-flux, lo-temp solder, etc ) that make it easier. I solder stuff every day and it's not as hard as it appears.
 
I managed to obtain a proper battery but it did not solve the problem, it is saving my CMOS settings but the system still will not even try to boot from a floppy disk. I tried both "use floppy first" and "use hard disk first" (the only boot options available) but either way it never tries to boot from floppy disk.
 
Does it even try to access the floppy drive when you set it to "floppy first"? If not, could be a simple power issue or a not-so-simple controller issue.
 
So after a LOT of troubleshooting, I finally figured out the problem, and I'm embarrassed at how simple the solution was.

I noticed that if I set the hard drive type to "None" in the BIOS, the machine would boot off a floppy disk just fine. But that of course meant I couldn't use the hard drive.

So I checked the spec page for the hard drive (a Conner CP2044PK) and I noticed the jumper section, so I checked the jumpers on my drive...and my drive wasn't jumpered correctly for single drive/master operation!

Once I fixed that I was able to install MS-DOS 6.22 to the drive without issue, I'm embarrassed that I didn't check this sooner as I could have probably had this computer fixed months ago.
 
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