SE/30 FDD stopped working correctly

[megabyte]

Hi all.

Recenlty my FDD stopped being able to format 1.4 floppies. But 800kb formatted perfectly.

I tried to:

• replace FDD from my Classic II
• replace FDD cable
• clear small puddles of electrolyte around capacitors on motherboard

Computer correctly determines the type of diskette, so sensor working correctly.

After formatting of 1.4 diskettes Mac OS show message about defective diskette, but another computer formatting it without any problem.

 

[bigmessowires]

Maybe the SWIM chip isn't working properly, or the logic board traces connected to it. I don't remember if the SE/30 has Bourns filters, but those could also be a problem. 1.4MB floppies use a faster data rate than 800K, so if the floppy data path is degraded, it might fail at 1.4MB speeds but still work at the slower 800K speeds.

 

[megabyte]

So the only solution will be the motherboard replacement?

 

[bibilit]

• clear small puddles of electrolyte around capacitors on motherboard

If your logic board has not been recaped yet, don't look any further....

 

[Scott Squires]

So the only solution will be the motherboard replacement?

No, have this one repaired. At this late date it is a surprise to find any non-recapped SE/30 that works at all. As time goes by, more and more of these boards will become unrepairable. Get it fixed while it still has a chance.

 

[megabyte]

Today I recapped a motherboard of my SE/30 - computer started working better, now I can hear a sound from a speaker

But FDD still can't work with 1.4 diskettes...

 

[techknight]

Probably because the damage has already been done. 

Try washing the board and getting all the residue off as well, and then youll have to buzz out all the connections on the SWIM IC. 

 

[Unknown_K]

Try cleaning the drive head, and then check the sensor that detects the HD notch on the disk is working.

There is a difference in media between the two:

DD: 2 µm magnetic iron oxide

HD: 1.2 µm cobalt-doped iron oxide

 

[megabyte]

Today I checked all lines that going to FDD connector on PCB. I used a scans of official Apple schematics.

No one of the lines are damaged. I also removed a bourn filter from PCB.

But still my SE/30 can't format 1.4 and 800k floppies...

 

[techknight]

what about all the connections to the SWIM itself from the various areas on the BUS? 

 

[megabyte]

what about all the connections to the SWIM itself from the various areas on the BUS? 

Good idea. I will check this tomorrow

 

[lubert]

@megabyte I'm encountering the same issue on my SE/30, just curious, did you ever fix yours?