HP 9114A floppy drive


I've just acquired one of these, but there's a problem with the power supply inside the unit. I can charge up the 6 V battery, but I don't get power to the output socket. I suspect a component on the little circuit board is dead. Does anyone have a circuit diagram for the board? I think I know which component has blown, but I'd like to be sure.

Many thanks for any help.



hi david please let me have a look i have the same problems and searching for a hp 9114 a or b.
By the way check in the power suplly box (open with
screw driver (flat)) You find a big matsushita battery
6,75 V 3 amps average ( i pick up in my mind) plus a print with little diode bidge 1 tip 41c transistor and some zener or other parts: One of these is a fuse .I supposed it a long time .Recently i discover this forum
and i found Tony Duell for sample who repaired this unit with an other HP user thru the forum .Tony Duell
confirmed my supposition the resistor have already
a siver or gold ring for tolerance and which one looks
like a resistor but doesn t be one. i check in my
data and give you the colors from the fuse.Tony Duell
said it could be a 3 amps use...which is logically adapted for the battery capacity.


Yes, I have the board with the TIP41A part, and three resistor-like parts in a row, of which the bottom one seems to be open-circuit. If I know what that part is I'll replace it, but I don't know how to tell. It's not marked like a resistor.


hi david you see tony duell is looking.. plus the forum
archive ...the resistors have three ring color and one ring
tolerance gold or silver almost so if you would to help
you with something you can live with a little part
or wiring one hair thick and so mine has work too till
i knew that the fuse has 3 amp.have luck


Hi david,
look at this
hp forum archive 9 Re Is there a fuse on the main board of the 9114 a? tony duell writing...
hp forum archiv 12 Re 9114b pinout tony duell writing..
so i confirm you the other mail have luck to repair it.
and if you can give me a tip to find a 9114 to buy...?
many thanks from Europe France Basel.


There was also a LCR-226P inside my Portable Plus.
Dead and replaced by a 6V 2.1A Adapter.
Now the unit works fine and I will try this solution on my 9114.
In a previous HP-110, I saw three Cyclon 2V 2.5A batteries.
The right values should be 6V 2.5A for the HP-9114 too ?!
To be continued...



There's a schematic of the battery pack (both versions), along with the rest of the 9114A and many other HP calculators and peripherals on the HPCC schematics CD-ROM.

There's a picofuse in these battery packs on the PCB, connected between the battery +ve terminal and the output. It looks like a resistor, and is normally rated at 2A (although I have seen 5A ones that don't look like they've ever been replaced. I would check this first.


You have email.


Andreas, thank you very much for the email, and for the drawings. I've found the part I need, and it will soon be working again. I'm very grateful.



Hi David,
I am happy if I could help you.
Best regards,


Hi andreas haetten Sie die zeichnungen von 9114 a oder b?

Hi andreas do you have the drawing from mother board
from the drive or the other from the system charger included in 88014?
I m interested in.
By the way tell to David Os that Tony duell has related
in forum a simple drawing for charger with transistor
and zener .
Myself i have successfully tested a system with an
old transformer like 82066 europe system then on the
output you sold a diode bridge plus a 100 mF 25v
so you filter then you put a LM 7808 regulator
and on the output a .1mF capacitor
Simple efficient .Low cost precise. Good signal on the
Scope flat clever.It do the job.I can give the schema
it also standardin all data books.Also looking for
9114 a or b to buy and 3 hp il cables .
THANKS for help
Chris E S


Hi Chris,
What I send to David are the schematics of both versions of the charger electronics I found in my own 9114A and 9114B units. These are the only schematics I have. So, if you want them please send me an email with your email address.
Best regards,

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