| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE | 
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 | 
| Moderator: | NETCAD::COLELLA DT | 
| 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 | 
We are seeing a high failure rate of DEWGB-MA at one site. 21 units failed in 4 months. I got a sample of 4 units and found that in all cases the DC-to-DC converted and the fuse feeding it are faulty. Sometimes it is the Work-Group DC-to-DC converter and sometimes it is the Back-Bone DC-to-DC converter. In one case the converter was faulty, but the fuse was food. We resurrected 2 out of 4 faulty units, because each unit has 2 converters and only one converter is faulty. This converter has a small daughter card with a tiny transformer and a couple of transistors and some capacitors. The BOM shows the P/N of this transformer as 20-45319-01. I vaguely recal seeing a similar daughter card on the H4005 transceivers that were manufactured in Australia, but I am not sure if it is the same part. Is there a quality issue with these DC-to-DC converters ? Could the fuse be over-rated, that by the time the fuse blows the daughter card is damaged or did the damaged daughter card blew the fuse ? This site has had these units for several years and it is only in the last 4 months 21 units have failed - I have been told. I don't know for sure if the remaining 17 units that were not given to me had the same problem. The LED would read as follows on the failed units: TOP MOST - GREEN ON 2nd from TOP- Green ON 3rd from TOP- Green OFF TOP Amber - ON Rest all OFF. Connecting to bridge via NCP or NCL through the working Ethernet Port would show the bridge continuously failing loop back testing. 1802:00-00-00-00 01 I connected via NCL or NCP to only one unit. The others I just looked at the LEDs. Alphonse
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 4372.1 | I just saw note 2172 | GIDDAY::STANISLAUS | Tue Apr 22 1997 22:33 | 7 | |
| Note 2172 has the same issue. In my case the revs are all D3. Probably the fuses are preventing the burning smell, etc. In my case there is no burning smell as written in note 2172 of this conference. There is no answer to note 2172 to say there is a fix. Alphonse | |||||
| 4372.2 | My customer has also had this for 4 years or so. | GIDDAY::STANISLAUS | Tue Apr 22 1997 22:35 | 4 | |
| My customer has also had this for 4 years like note 2172 says. Is this a 4 years lifetime Dc-to-DC converter ? Alphonse | |||||
| 4372.3 | Yep, there is an issue.. | PTOSS1::DANZAK | Pittsburgher � | Tue Apr 29 1997 22:13 | 5 | 
|     There is a DC-DC converter problem - call Michelle Bigelow DTN 226-5168
    for more info...but I think that it has to do with some parts from a
    3rd party which were out-of-spec etc.
    
    
 | |||||
| 4372.4 | ECO DEWGB-LKG006 solves this Problem | ZUR01::ACKERMANN | Wed Apr 30 1997 06:08 | 31 | |
|     
    
    Hello together,
    
    We had here in Switzerland on some Customer Sides the same Problems
    with the burned DC-DC Converters. We replaced the Modules with higher
    Revisions.
    I went to our Local Digital Repair Center. From there i have get
    the following Infos:
    
    There are known Problems with the DC-DC Converters with DEWGB/DEWGF
    Units and there are ECOs implemented to solve these Problems:
    
    The DEWGB ECO:
    --------------
    
    ECO#            DEWGB-MA        DEWGB-M    Etch FW Rev. ROM Rev
    
    DEWGB-LKG006    F04             E04        H1   V3.9    V2.2
    /6A             F02             E02        F1   V3.9    V2.2
    
    With the  ECO#  DEWGB-LKG006 the DC-DC Converter Rework is done.
    
    
    Regards,
    
    Daniel MCS
    
    Network and Communication Support Switzerland
    
    
 | |||||
| 4372.5 | And another ECO for the DEWGF | ZUR01::ACKERMANN | Wed Apr 30 1997 06:10 | 25 | |
|     
    
    Hello again,
    
    Here is the ECO Info for the DEWGF:
    
    
    The DEWGF ECO:
    --------------
    
    ECO#            DEWGF-MA        DEWGF-M   Etch  FW Rev. ROM Rev
    
    DEWGF-LKG003    C05             E03       D1    V3.9    V2.1
                    C03             E01       C1    V3.9    V2.1
    
    With the  ECO#  DEWGF-LKG003 the DC-DC Converter Rework is done.
    
    
    Regards,
    
    Daniel MCS
    
    Network and Communication Support Switzerland
    
    
 | |||||