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HP Forum Archive 17

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9114A woes
Message #1 Posted by PeterP on 9 May 2007, 1:31 a.m.

Hi,

Thanks to Tony's wonderful article (and lots of other goodies I found here in the archives) I mustered the courage to open up my 9114A drive to try to get it to work. I carefully disassembled the drive and cleaned all things out. Now when pressing the eject button an inserted disk comes out very easily (I actually was lucky as I did not have to disassemble everything, grease-lock was not that bad)

However the original problem persists:

When turned on (no disk) both of the LEDs turn on (the one marked power and the one marked fault) and stay on. The little LED underneath the disk flickers a little bit once in a while but no sustained light.

When turned on with disk inserted the behavior is exactly the same. I also hear no movement of the head or anything the like. Erie silence is all I get...

naturally I have the charger plugged in and while I understand that this might not be enough to use the drive (though the postings in the archive diverge on this point at times...) at least I would expect the fault light to go off...

I measured the power coming out of the charger and it is 8.8V (my voltmeter is not very accurate).

So with my limited latin at its wits end I turn faithfully to the group for advice on the next steps. I read posts about how to replace the battery pack yet at this point I'd like to avoid having to try this without knowing that this even has a chance of being the sole culprit. And somehow this does not seem to likely at this point.

Steve mentions in his article in the article section that there is a chance that the HP-IL interface in the drive is faulty/broken. How could this happen and how could I test that the HP-IL in the drive is fine? I do have Extended IO and the Devil for the HP 41 and Data Acq and Data com for the 71 (but I'm greener than spring grass behind my 71b ears!) in case that would help.

Thanks a lot for all you who have listened until here and even more to those who kindly are willing to offer some advice!

Cheers

Peter

      
Re: 9114A woes
Message #2 Posted by Tony Duell on 9 May 2007, 6:01 a.m.,
in response to message #1 by PeterP

Firstly, the battery must be good for the 9114A to pass the self-test. During the self test, the unit spins the disk and moves the head about (which are the operations that take the most power from the battery, of course), so if the battery is bad, it'll not manage to do that. The charger will NOT be enough on its own.

You can get my schematics for the 9114A from the Australian site. I would start by looking at pages 1 and 2 of the controller PCB schematic, which are the PSU section. There are 3 power rails in a 9114A -- Vc, which is 5V all the time the unit is switched on (it powers the RAM chip, etc), +5V, which powers the rest of the logic and which is turned off when the unit goes into powersave mode, and +12V, which is only turned on to the drive power connector when the unit needs to operate the disk drive motors.

Check the output of the battery pack when the unit is turned on and performing the self-test. A convenient way to do this is to connect the -ve side of your meter to the drive chassis (this is connected to the unit's ground rail) and the +ve side to one of the wires on the back of the power switch. You should get 6V here, it should not drop during the test.

Then measure Vc on TP8. Then check 5V on TP10 (this should be present during the self-test). And finally check the +12V line on TP9 (TP11 is the common ground connection for the -ve side of your voltmeter).

If all that checks out, then I think you're going to have to get into the controller board logic circuitry. Do you have a logic probe, logic analyser or oscilloscope?

            
Re: 9114A woes
Message #3 Posted by PeterP on 9 May 2007, 11:46 a.m.,
in response to message #2 by Tony Duell

Tony, Luiz,

Thanks so much. Again. :-)

So the first thing I did is to search for the right replacement battery in the archives. Many people seemed to have used the Powersonic PS-628 with great success. It still can be found here for 20 USD.

So my next step will be to replace the batter pack and try again. In the meantime I'd love to try study the suggestions from Tony, yet I do not know the Australian site? Can you point me in the right direction, please?

BTW - I was amazed at the level of detail and care in your article about the cleaning of the drive, quite exceptional! I almost failed before I even started due to those deeply recessed torx screws to open the drive, as I have no torx drivers. Turns out I had an exact fitting flat-head (?) screw-driver which worked as well. I read in a post that the 71b need a 6 and the drive is an 8, but there is also a thread which claims it is a 9. Would you happen to know the size Torx needed for the drive?

Thanks again, and I will most definitely keep you all in the know of how your student is doing.

Cheers

Peter

                  
Re: 9114A woes
Message #4 Posted by Tony Duell on 9 May 2007, 1:47 p.m.,
in response to message #3 by PeterP

Quote:
So the first thing I did is to search for the right replacement battery in the archives. Many people seemed to have used the Powersonic PS-628 with great success. It still can be found here for 20 USD.

I have long been of the opinion that before you change any components -- yes, even batteries -- you should do tests to find out what is wrong. This may not be the way of the modern board-swappers, but all I can say is that my stuff keeps on working..

Before you spend $20 on a new battery, I really would check the voltage. If you take the top cover off the drive, it's really easy to do. I'd do it without the charger connected, you're more likely to show up a dead battery that way. If the voltage is lower than 6V, or if it drops when the unit tries to do a self-test, then change the battery, sure.

Quote:

BTW - I was amazed at the level of detail and care in your article about the cleaning of the drive, quite exceptional! I almost failed before I even started due to those deeply recessed torx screws to open the drive, as I have no torx drivers. Turns out I had an exact fitting flat-head (?) screw-driver which worked as well. I read in a post that the 71b need a 6 and the drive is an 8, but there is also a thread which claims it is a 9. Would you happen to know the size Torx needed for the drive?


Alas I don't know. My toolkit contains all sizes from TX3 (!) up to TX70. I know I had a tool that would fit it... Sometimes I forget that not everyone has literally hundreds, if not thousands, of tools...

It's the same size as the 2 screws on top of the battery pack. You could take that to a good tool shop and see if they can find the size that fits it.

                        
Re: 9114A woes
Message #5 Posted by PeterP on 9 May 2007, 1:55 p.m.,
in response to message #4 by Tony Duell

Tony,

Thanks for your fast response.

You are absolutely right. I forgot to mention this in my thread - I did test the output voltage of the battery. if unconnected to the charger it is just a couple of volts at best, it almost appears close to 0 (my voltmeter is not that good, and neither is the operator...). However, with the charger attached and the charger plugged in I get the full 8.8 Volt. So from that I inferred that the battery is dead. Please correct me where I did something wrong (other than not telling you about it, silly me...)

Will follow your advice on the Torx, especially as it needs the long shaft. You can buy a whole set for 10 USD over the internet, but they all have only 50mm shaft and then I'm not too sure about the quality...

last but not least, can you be so kind and point me to the australian site so that I can get my hands on your schematics?

Thanks so much!!

Cheers

Peter

                              
Re: 9114A woes
Message #6 Posted by Klaus on 10 May 2007, 1:44 a.m.,
in response to message #5 by PeterP

The Australian site has the same domain name as this site, but has a .net instead of a .org

                              
Re: 9114A woes
Message #7 Posted by Tony Duell on 10 May 2007, 4:30 a.m.,
in response to message #5 by PeterP

Quote:
Tony,

Thanks for your fast response.

You are absolutely right. I forgot to mention this in my thread - I did test the output voltage of the battery. if unconnected to the charger it is just a couple of volts at best, it almost appears close to 0 (my voltmeter is not that good, and neither is the operator...). However, with the charger attached and the charger plugged in I get the full 8.8 Volt. So from that I inferred that the battery is dead. Please correct me where I did something wrong (other than not telling you about it, silly me...)


That pretty much shows your battery is dead. It's fairly easy to replace it, you remove the 2 screws on top of the back, free the cover from the little 'clips' round the edges, and the battery just lifts out. The wires go on with 'faston' spade terminals, as expected the red wire is +ve.

Quote:

Will follow your advice on the Torx, especially as it needs the long shaft. You can buy a whole set for 10 USD over the internet, but they all have only 50mm shaft and then I'm not too sure about the quality...


All I can say on quality is that some of my Torx drivers cost over $10 each...

Quote:

last but not least, can you be so kind and point me to the australian site so that I can get my hands on your schematics?


I don't think David Hicks likes us mentioning other sites here. I did try to send you a private message giving the URL of that site, though.

                                    
Re: 9114A woes
Message #8 Posted by PeterP on 10 May 2007, 1:41 p.m.,
in response to message #7 by Tony Duell

Thank you Tony and Klaus. I added another link to my HP41 link selection, very nice and very much appreciated!

If and when the batteries arive and I have made the replacement, I will most definitely report on the outcome.

One question - I have scourged the archive for articles on 9114 and it is true that especially the question about the batterie is coming up with high regularity. As for cleaning, there is Steve's article here.

Tony, I was wondering if it would make sense for me to put together a little primer on the various subjects that can be found in the archives and the answers from the experts (you, Steve, Garth, etc) and create a little 'Review of Questions about the 9114' article that can be added to the article section and you can point to it in the future for easy reference. I must have read at least 7 posts of you talking about the the difference between 9114a and 9114b, 300rpm PC and 600rpm 9114, etc :-) Also, I was wondering what your options are with regards to the article you submitted to Datafile - does that mean it now belongs to them and it can not be posted here? I think the pictures and detailed description make a very nice complement to Steve's article here.

Naturally, I would want to ask you and/or the forum to 'proof read' that summary article before suggesting it to Dave, but I thought it might be useful for others at least as a starting point. What do you think?

Cheers

Peter

                                          
Re: 9114A woes
Message #9 Posted by Tony Duell on 11 May 2007, 1:41 p.m.,
in response to message #8 by PeterP

Quote:
One question - I have scourged the archive for articles on 9114 and it is true that especially the question about the batterie is coming up with high regularity. As for cleaning, there is Steve's article here.

Tony, I was wondering if it would make sense for me to put together a little primer on the various subjects that can be found in the archives and the answers from the experts (you, Steve, Garth, etc) and create a little 'Review of Questions about the 9114' article that can be added to the article section and you can point to it in the future for easy reference. I must have read at least 7 posts of you talking about the the difference between 9114a and 9114b, 300rpm PC and 600rpm 9114, etc :-) Also, I was wondering what your options are with regards to the article you submitted to Datafile - does that mean it now belongs to them and it can not be posted here? I think the pictures and detailed description make a very nice complement to Steve's article here.


Sounds like a good idea.

As regards the article in Datafile, I still own the copyright on that (although obviously I've given HPCC the right to reproduce it -- but not the exclusive rights).

Now, I don't have modern things like a graphical display on my PC, or a digital camera. Therefore, that article was submitted to HPCC in bits -- a CD-ROM of pictures produced by the minilab that processed and printed my film (some of those pictures had nothing to do with 9114s at all!), and a text file of captions and which photos to stick in. Bruce Horrocks (HPCC editor) put it all together for me.

I've suggested that he puts a copy on the web somewhere (I would certainly be happy with that), but AFAIK he's not had time to sort it out.

                              
Re: 9114A woes
Message #10 Posted by Dave Shaffer on 10 May 2007, 2:40 p.m.,
in response to message #5 by PeterP

PeterP: "(my voltmeter is not that good, and neither is the operator...)"

Do you live in the USA? If so, let me suggest that you check out the cheap Sears DVM. I note that here in Arizona, at least, the latest Sears sale circular shows it for $10. I have one, it works well, and is nice and small so you can carry it almost anywhere.

I don't think Sears will sell you a new operator, though!

                                    
Re: 9114A woes
Message #11 Posted by PeterP on 10 May 2007, 5:32 p.m.,
in response to message #10 by Dave Shaffer

:-) a new operator would be cool, woudn't it?

Thanks for the tip, will check it out!

Cheers

Peter

                                    
Re: 9114A woes
Message #12 Posted by Tony Duell on 11 May 2007, 1:43 p.m.,
in response to message #10 by Dave Shaffer

Quote:
PeterP: "(my voltmeter is not that good, and neither is the operator...)"

Do you live in the USA? If so, let me suggest that you check out the cheap Sears DVM. I note that here in Arizona, at least, the latest Sears sale circular shows it for $10. I have one, it works well, and is nice and small so you can carry it almost anywhere.


Having had so many problems with cheap DMMs and VOMs over the years, I now only use what are considered to be good quality brands, like AVO and Fluke. Yes, they're expensive, but they're worth it IMHO, if only in terms of the time saved by not having to worry if the readings are sane.

Quote:
I don't think Sears will sell you a new operator, though!

Alas that's a lot more important than the instrument. The best piece of test gear is a brain, as I've said many times...

                                          
Re: 9114A woes
Message #13 Posted by Dave Shaffer on 11 May 2007, 10:47 p.m.,
in response to message #12 by Tony Duell

Tony,

When it counted (i.e. I was getting paid for the job!), I did use a Fluke (paid for by my company). But when I'm paying for it, I tend to go downscale a bit. So far, my Heathkit DVM, along with its Radio Shack and Sears companions have functioned way beyond what I might have expected. I don't use them very hard, but when I need them (perhaps once a week) they seem to perform more than adequately.

The requisite brain, to make sure it is all working OK at the expected levels is, indeed, an important part of the equation, though.

      
Re: 9114A woes
Message #14 Posted by Vieira, L. C. (Brazil) on 9 May 2007, 6:19 a.m.,
in response to message #1 by PeterP

Hi;

mine had similar problems that definitely disappeared after replacing the sealed battery for a new one, as Tony clearly mentions in his post. Im adding this followup just to reinforce Tonys post with my own experience.

Cheers.

Luiz (Brazil)

Edited: 9 May 2007, 12:23 p.m.


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