_ DEC-O-LOG for DNSBX_O001

_ DOL, DNSBX-O001, Potential for short in transformer

FEB 94

APPLICABILITY: This is an "O" coded FCO and it 
should be installed on all   DECnis 600 platforms: 
DNSBX-AD, DNSBA-BC/BD, DNSEA-BC/BD, 
DNSEB-BC/BD,   DNSEC-BC/BD, DNSED-BC/BD, 
DNSEE-BC/BD, DNSEF-EE/BD, DNSBB-BC/BD, 
DNSBD-BC/BD.  This FCO will replace the H7720-AA 
(30-36324-01) with revision "C01".	

PROBLEM & SYMPTOM: Under certain failure 
modes, there are indications for   a potential cause of 
an electrical short in the transformer. This could   re
sult in the power supply overheating. The symptom is 
an unexpected failure  of the device due to loss of 
power. This may be accompanied by release of smoke. 
This is not a safety hazard.

SOLUTION: The solution for this problem is to re
place every power supply H7720-AA below revision 
C01 with revision C01 or higher. However, because   
the DECNIS 600 is a key high-end networking prod
uct, FCO implementation will need to be scheduled in 
advance with customers. The customer and Field   
Service will need to agree and schedule a "non-critical" 
time to have the PSU replaced.	

QUICK CHECK: All good and fully tested PSUs will 
be at revision C01 or   higher. All "suspect" PSUs will 
be at lower revisions; either A01, B01, B02   or B03. 
The revision number is situated immediately under 
the AC input   socket.	

FCO KIT ORDERING:
EQ-01683-01   30-36324-01 Power Supply, Rev C01
FA-05020-01   FIELD APPLICATION  (FA) DOC