HP 9121D

For more information, see this article's corresponding Wikipedia page: Device.

HP 9121D

Preliminary Information
Release Year	1982
Leak Risk	Low
Batteries	None
Mounting Technology	Through Hole, SMD, BGA, Sockets
Capacitor Types	Aluminum Electrolytic, Ceramic
Destructive Entry	No
Hardware Specifications
Storage	3.5in Single Sided Double Density Floppy Disks
Power Requirements
Power Connector	IEC C13/C14 Socket

HP dual floppy drive with Sony OA-D31V-14 model floppy drives.

Known Issues

Disk not spinning

Causes

• Magnetic hall sensors failsure
  • Test by removing motor assembly, directly powering, and nudge motor to start spinning

Solutions

• Replace hall THS103A sensors

Cracked D10 Diode

Causes

• Bent flat when reassembled and crushed by screw post

Solutions

• Replace diode

Disassembly Notes

Diode D10 next to one of the screw holes on logic board is very easily pinched when reassembling and may be cracked. Be sure to bend it upright before putting PCB back onto chassis

Original Parts

Main Logic Board

FC-6

Capacitor Specifications and Footprint Information

RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
		0 µF						0 °C

Replacement Parts

Basic PCB Name

Capacitors

RefDes	Qty	Compatible Part Number	Order Links
			Digikey

If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric searc

Related Links

• More Information: https://wiki.techtangents.net/wiki/HP-9121D_3.5%22_Double_Density_Single_Sided_Floppy_Drive