You wrote...
> Thanks for the info. I tried to call you yesterday.
Sorry, work has been such a royal PITA I turned my cellphone off yesterday
and when it's on I've recently taken to not answering calls from numbers I
don't recognize. My apologies! :\
> The 2114 was one of
> the things that I wanted to talk to you about. I have a couple of other
> questions. How hard is it to find media for the 7900?
Fairly difficult. I may have one or two spare we can talk trade, if you can
find them in a real shop that deals in media, expect $140 each.
> (BTW I do have a PT
> reader and the 7900 PSU is there and it's all in an original HP cabinet.)
Very nice!
> How do I get the 7900 open? Aren't you supposed to apply power get them
> open?
You have to apply power to get the front door to open so you can remove the
media, that is safe to do. What I was referring to about don't power it up
until cleaning and inspection is really dont hit the LOAD switch. You also
have to be VERY carefull about removing the media in an unknown condition
drive. If the heads did come out (the carriage extended during moving), when
you open the front door it tilts the media up. You grab the media and pull
it out. If the heads loaded, this action will bend the head arms and scrape
the heads across the media and then you're pretty screwed!!! Here is what I
would suggest:
1) extend the drive out of the rack on it's rails all the way. Make sure the
anti-tip legs are out, if the cabinet has them. Be carefull about tipover.
1a) make really sure the drive is unplugged from any power source
2) Take the top cover off the drive, it's about 4 or 6 screws on top
3) Visually inspect that the carriage is all the way back. It's ok to move
it forward (if they are all the way back) maybe 1 inch, you'll feel the
detent. Of course, watch that you don't move the carriage so far forward
that the heads go out on the media - you can see if they do pretty clearly.
Then push the carriage back - you should again feel the detent and you'll
see the heads get spread apart slightly on the plastic block thingy between
the head arms.
4) Now that you're sure the heads are back, you can apply power, and in
about 3 seconds the "door unlocked" light should come on. Ok to open the
door and pull the media out then, and power off. While it's on and "door
unlocked" you probably want to look and see if the "drive fault" light comes
on or not.
5) As you'll tell from the detent pressure when you move the carriage, it
doesn't take much of a jolt for the carriage to come out, so be carefull
moving this drive.
6) If you can't move the carriage by hand at all, look around the carriage
assembly to see if there is a metal bracket screwed in that obviously
prevents the carriage from moving. Remove it - well, once you're ready to
work on the drive.
7) Be cognizant of the detent - your detent may be tighter than mine. Just
be aware as you try to move the carriage forward that once it does pass the
detent it will move very easily, and you dont want to yank it suddenly
forward so the heads go over (on) the media.
8) While the drive is extended, open the bottom of the drive, again, should
be about 4 or 6 screws. With the bottom cover removed you should be able to
see the power regulator board. On this board are some nicad batteries, I
think about 3 or 4. Take these out and go buy new ones. They are not a
particularly hard to find battery, batteries plus should have them. These
batteries are what retracts the carriage if power is lost while the heads
are loaded. You want to be very sure you have a good set, or if you trip a
breaker or hit the power switch before the unload switch you'll be very
sorry :)
9) As a result of the new nicad batteries, once they are installed, turn on
the drive and let it sit for a few hours (do not load the heads [do not hit
the load switch]) so that the batteries get charged up well.
10) I can't stress enough how clean the inside of the drive must be. Clean
everything you see very very thoroughly. Be carefull of the head wires on
the right, they are quite thin and fragile. Just one spec of dust is all you
need to destroy your heads and platter. HP suggests masking tape around your
fingers sticky side out and touching everything to get dust & particles -
also 91 iso and kimwipes.
11) Under the drive take out the filter, and the big orange blower tube.
Clean the filter best as you can, and run a big brush through the tube
several times, get it all out. Clean the squirrel cage blower very
thoroughly. I usually take the squirrel cage out and use a toothbrush with
solvent, the dust on the squirrel cage fan is usually compacted and hard.
Pay attention to the chamber where the squirrel cage fan is too. When you
take out the filter, the bottom (fixed) platter will be exposed. Be VERY
carefull not to knock any dust up there, or drag a wire or tool across it. I
normally tape a cut to fit file folder card over the opening while I'm
cleaning the rest.
11a) clean the upper and lower heads on both the fixed and removable
platters with a qtip and 91% ISO. Be very gentle!
11b) it's best to clean the fixed platter. I seem to recall there is an
opening in the casing to do this. I'll check where it is when I get home.
12) Disassemble your media cartridge, and clean it thoroughly. Get EVERY
spec of dust out. Put a padded towel on a table, put a few kimwipes down,
and put the bare platter on it. Clean both sides thoroughly with ISO 91 and
kimwipes. Good idea to buff it too. Do NOT use anything other than kimwipes.
Reassemble the cartridge.
13) It's ok to run the drive with covers off for short periods. Leave the
top cover off and put in the media and power up. Hit the load switch. The
heads will load in 25 seconds. Count till about 23 seconds, or, when the
heads start to extend, and hit the unload switch immediately. Repeat this
process several times. What you're trying to do is, when you hit the load
switch the blowers come on, thus expelling any particles from the fixed
drive chamber and the media cartridge. Doing this a few times gives a good
blowout before you actually try to let the heads fly.
14) Now, hit the load switch, and pray. Watch carefully after 30 seconds and
see the heads load. Listen very carefully for any sounds of HDI and soon as
the heads are over the surface, hit unload. Do this a few times (getting the
heads off soon as they start flying). Then, hit load and let the heads come
out and sit. Listen very carefully for HDI. If you hear any wisps or clinks
or drags, hit unload and find out why.
15) If the heads load and fly for 30 seconds after the load switch is hit,
look at the front of the drive. If you see "drive fault" hit unload and
power the drive off. You'll need some help troubleshooting from there. If
instead of drive fault, after 30 seconds you get the "drive ready" light,
you're all cool. Of course, you MAY have a burned out "ready" light, be
aware of that.
Those are the big points I can think of. It was a long time ago that I
refurbed my 7900A, some of the specifics above may refer to a 7906 which is
more recent in my head, but the main gist should all be correct.
> What is the capacity of the 7900 drive?
5mb. 2.5mb on the removable platter, and 2.5 on the fixed platter
underneath. Unless you have a 7901A, which doesn't have a fixed platter in
which case it's 2.5mb.
> Where do the IO cables come
> out of the 2114? There were NO cables connected to this one. I pulled the
> entire chassis out of the rack.
I'm not up on the 2114. It's the same as the 2100 and 21MX, only slightly
different :) There should be one section of the card cage for the memory
subsystem, and another section of the card cage for I/O cards, and another
section for the cpu cards. The disc drive should hook up to a "13210" disc
controller (two card set) in the I/O section, same place roughly where you
see the buffered tty board.
> There are Buffered TTY boards and such in
> the chassis. I suspect that the IO cables plug into those kind of cards
and
> are supposed to run directly out the back. If so then it's missing the
> cables.
Again, I'm not up on the 2114, totally different series than the 2100 and
21MX series. But, as I said, if there's no cables running from the drive to
the cpu, then check the back of the drive. On the back right of the drive,
there should be two slots. One slot should have a terminator card plugged
in, usually with little extraction handles. In front of this, 1/2 inch
closer to the back of the drive, should be an edge card connector sticking
straight up, this is what your drive to cpu cable would connect to. This
cable may be connected to the drive but the other end may be just loose in
the bottom of the rack. Or the cable may be in the bottom of the rack not
connected to anything. The cable, on both ends, should say "7900" or "13210"
on the hoods, but this frequently wears off. If you don't have a cable set,
I can get you the pinouts for the cable, but it's not easy to find the end
connectors. I may or may not have a spare 7900 cable, they aren't common at
all.
> BTW here's list of the cards that are in it. Note that the ,s in this
> list are as shown on the cards. I'll use ; to separate the items. A1,2;
> A1,2; A3,4; A5; A6; A6,7; A8-11; A8-11; A8-11; A8-11; A8-11; A12; A13;
A14;
> A15;
Hummm... those are most likely the cpu cards. Are you sure you read these
off the card extractor handles, and not off the chassis? They sound like
slot designations. No, wait... Ax should be cpu cards. But I'm very suprised
there is so many cpu cards in a 2114. Maybe they combined the cpu and memory
sections on the 2114. Memory boards should be pretty obvious visually. I
know the 2100 and 21MX but not the 2114. Should be similar, but my knowledge
may be a bit off for the 2114.
> Bus IO; Bffr'd TTY Reg; Dual D/a Conv; Relay Out Reg; Gnd True I/O;
> Bffr'd TTY Reg; Multiplex I/O; Time Base Gen.
Bus I/O - pretty sure this would be the board that connects to the expansion
chassis
buffrd tty - this is a 12531 board, for a system console. Depending on the
exact part number, could be 20ma current loop, could be rs232, could be
both, I forget the max baud rate, I think 2400. Depending on the exact part
number, you probably have to solder jumpers to change settings.
Dual D/A conv, relay out reg, gnd tru I/O - these are all data acquisition
stuff, perhaps one for the paper tape reader
multiplex I/O - good question, can you get part numbers for this? My first
blush guess would be multiple serial ports?
TBG - provides system interrupt via programmable delay - a clock of sorts.
Used by most everything.
This is odd - there should be a 13210 two board set for the 7900. The paper
tape reader should be using an 8-bit duplex register, forget the part
number, something like 12566. However, I have heard really old HP's hooked
the paper tape up to a different kind of board than I'm used to using, maybe
the multiplex I/O.
What I need are the part numbers off the I/O boards. This were normally
written on the extractor handles. If not, take out the card and look for a
number like the following format "13210-60002". The first number is the
board type, the second number means many different things - options, field
replacement vs. factory install, etc.
>
> On the I/O Config Chart it shows "HP Data 70", "TTY 70" and
"Multiplex
> IO".
Doesn't ring any bells to me. Maybe RTE device addresses.
> There are only three cards in the IO Expander. They are; A112, A112 and
> Univ Intrf.
That's just odd to me. I/O cards are not called Axxx, I/O card are called
things like 13210, 13181, 13183, 13215, etc. Look on the cards themselves.
Hope this helps!
Jay
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Received on Wed Jan 14 2004 - 10:03:03 GMT