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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

3061.0. "Hub 900 modules & microswitches." by KERNEL::WARDJO () Tue Dec 12 1995 08:21

    Hello,
    
    A customer has called to register his concern about the quality of the
    microswitches in our Dechub900 range.
    
    He has purchased a variety of modules and on a high proportion he has
    had problems getting the units to power up (this is in different hubs).
    He has also had modules loose power while in the hubs.
    
    I was hoping to get some serial numbers of the devices concerned but
    the customer is unable to provide this.
    
    Are there any known issues regarding these microswitches?
    
    Regards,
    
    Jon
    
    UK CSC
    
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3061.1Seated properly?SCASS1::TERPENINGTue Dec 12 1995 11:392
    Are the modules properly seated and the latch fully closed? The problem
    you discribed happens often when the modules are not seated properly. 
3061.2Customer said yesKERNEL::WARDJOMon Dec 18 1995 08:138
    
    The customer has said he is inserting the modules correctly & pushing
    the catch down. He sees this as a design problem, but I am not convinced 
    he is inserting the modules correctly & was wondering if anyone else is 
    seeing this or if it is a problem just for this customer.
    
    
    Jon
3061.3STRWRS::KOCH_PIt never hurts to ask...Mon Dec 18 1995 10:419
    
    Well, occassionally the handle on the DEChub 900 don't always engage
    but just a slight pressure seats the handle which engages the
    microswitch. However, this is only when I lift the handle. Having my
    own demo gear, I literally slam the unit into place and the handle
    always engage. 
    
    I think the only way engineering might see what you are talking about
    is to videotape the customer doing it and sending in the tape. 
3061.4Try straightening out the lever instead of "slamming"NETCAD::BATTERSBYTue Dec 19 1995 12:0623
    I have watched people "slam" units into the HUB (much to my 
    dismay). It doesn't take too much of this "slamming" before
    the result is bent pins on some of the modules, or cracked
    and broken connector shrouds. I personally don't advocate the 
    "slamming" approach. Yes I know Ma Bell designed the telephone 
    such that people (frustrated by a busy signal at the other end), 
    can "slam" the receiver down and not have to worry about breaking 
    the phone, but I'd prefer to see a less aggressive approach to 
    installing modules in a HUB backplane. Try plugging the module
    in a gentler fashion, and then try repeated "snaps" of the little
    guillotine latch to get the module to power up. Failing this take 
    the module, hold the end of the module with the little lever near
    your ear so you can hear the "click" of the microswitch as you press
    down on the lever. If the "click" isn't heard until almost the end
    or at the end of the physical travel of the lever, then the lever
    must be straightened out a little so that the curved end of the 
    lever will make contact with the bottom edge of the guillotine latch
    sooner in its travel. This is usually the source of the problem. That
    is the curved end of the lever is bent too much, and needs a little
    subtle straightening out.
    
    Bob
    
3061.5STRWRS::KOCH_PIt never hurts to ask...Tue Dec 19 1995 13:2314
    
    OK, but I've had my units for well over 1 yr now and they regularly
    take a beating. I've heard of one sales rep who take a DECrepeater
    900TM out of a demo hub, jumps up and down on it and then replaces it
    into the hub and shows the customer how it powers up. 
    
    The modules are built like tanks. It's one of the edges we have in the
    marketplace by demonstrating our superior module engineering. I use to
    carry my modules around in a cardboard box until I found these real
    nice Rubbermaid storage containers. 
    
    I agree that a less agressive approach might work for this problem, but
    the sales end of this requires an agressive, push it as far as you can,
    approach to demonstrate why Digital engineering is the best.
3061.6To each their own.....NETCAD::BATTERSBYTue Dec 19 1995 14:067
    Oh I don't mind the standing on them and jumping up & down on 
    them. The box is built to take a certain amount of that. :-)
    I'm more concerned about the fragility of the plastic around the
    connectors, and bending pins when "slamming" a module while taking
    one eyes off what one is doing.
    
    Bob :-)
3061.7Thanks for the advice...KERNEL::WARDJOThu Dec 21 1995 07:2612
    Thanks for all the replies,
    
    I don't think I will advocate the customer jumps up & down on his modules
    or slams them into the hub. 
    
    As I have not actually witnessed him inserting them, I cannot be sure if 
    he is doing anything wrong. Perhaps he has been unlucky in having
    several modules where the switch only just engaged.
    
    Thanks again,
    
    Jon