Working on a 9114B HP-IL Disk Drive

[Gerry Schultz]

To All:

I recently purchased another 9114B floppy drive from that unmentionable place as it was sold "As Is". There was something banging around inside when it arrived so before testing, I opened it (it's so much fun finding the right spline tool) and found a metal tag of some kind. Anyway, it appears to be a pristine unit internally as indicated by a small amount of tape still holding the front of RF shield on the floppy drive itself.

The unit accepts and ejects floppies fine but reluctantly. I tested it with EMU41 and it read a floppy directory so it appears to work. The battery is bad and have ordered a replacement. I am concerned about the extra effort required in ejecting a floppy so I went here to this site and read PeterP's excellent article (876) and Steve's excellent article (78) about repairing the 9114.

It appears most of the problems are with the 9114A version, so should I be concerned with cleaning and lubing the eject mechanism? I have no problems tearing into this unit as I was buying it for parts but it seems to be in great shape so I'm thinking of getting it back in shape. Is there anything special I need to be careful of that is not covered in the articles mentioned before?

Any input about your experiences with the 9114B are appreciated.

Thanks,

Gerry

[Sean Connor]

Gerry,

Where did you order the replacement battery from ? Are you just replacing the internal cell/s ?

I have a 9114A with no battery at all that I run from a power supply.

Sean

[PeterP]

Gerry, congrats on finding a good unit, they are rare!

When writing the article (thanks for your generous words) I was actually repairing a B-unit - with the invaluable help of the master himself, Tony Duell. The B-Unit seems to be generally in better condition etc then the A-units, especially with regards to battery live. I'd try to determine where the stuck eject is coming from. As you have read, forcing a disk out when it is stuck rips off the head and that is, well, bad...

So I would try to figure out where the eject is stuck and lubricate it, starting with minimal dissassembly and working my way towards more intense dissassembly.

Hope that helps.

Cheers

Peter

[Diego Diaz]

Hi there,

I think these pics may be of some help.

The "metal tag" you found rattling inside your unit is more likely the top head cover... (red circle -also missing- in the image) which is supposed to be covering, and magnetic shielding, the upper head circuitry. Your 9114B can live without that... ;-)

The eject mechanism is commanded by the gears and spring inside the green cirle. May be just a bit (use very little please) lubricating grease (not oil!) will help smoothening the ejection.

If you plan to leave your 9114 unit unused for long periods of time, it's highly advisable to put a dummy disk like the one in the picture below. to protect the heads. A cleaning disk can also be used (and are easier to find). Do not leave a real disk inside the unit as the magnetic coating may end up tearing from the disk substrate damaging the heads (as Peter has pointed out above)

Regarding the battery, although the original part (Panasonic LCR-226P) is no longer in production (AFAIK), you can easily find a matching replacement (PM631). Terminals are not in the same position but this can be worked out.

Best wishes.

Diego.

[Gerry Schultz]

Thanks, Diego. One picture is work 4K words in this case. I can't remember how many of those 3.5" dummy disks I threw away when I got new drives in. It seems that I just have to be careful when I clean and lubricate the drive mechanism. I've done it before on IBM PC floppy drives so I'm not worried.

You're right about the top head cover. It's the right size and shape. I'm just glad I removed it before I applied power. What a great way to ruin a new (to me) piece of equipment by having a piece of metal floating around in it.

Peter, your article is very good and thank you for sharing the fruits of your labor with the rest of us. I am lucky to find such a rare drive and I want to have it last for a long time.

Sean, I googled for a PowerSonic PS-628 as, according to Peter's article, it is a direct replacement battery. I ordered two from batteryplex.com as I want to replace a second one as well. They cost only $11.80 and they should get here early next week.

Thanks for all the responses.

Gerry

[Gerry Schultz]

A small follow up to close out this thread. I have received and installed the two PS-628 batteries and they work great. I wrote a small program on the EMU41 that looped through selecting and retrieving directories from the 9114B drives as a way to test the charge/discharge cycle of the power supply assembly. I was looking to confirm that the charging board would properly recharge the battery and it seems fine.

It was interesting to note that running the loop in EMU41's fast mode kept both drives lights on all the time with directory listing whizzing past on the screen. It still took over an hour for the batteries to discharge down to empty.

I will bring them to the HHC 2009 conference that starts in about 10 days.

Thanks,
Gerry