On Sat, 10 Oct 2009 11:11:08 +0100, "N_Cook" wrote:

:Went to use it this week , first time for ages and not a dickybird, no magic
:smoke/ ominous noises. Just single cycle slow repeat ping/clicks from the
:inverter transformer. Was working fine last time of use.
:Anyone happen to have schematic of the ABI DDS-40XP Digital Diagnostic
:System or more pressingly the SMPS, I only have the ABI user manual
:I may be able to get away with 2 SMPS replacement fitted in there, the
:Coutant (maybe type number B91510 ) from 1988 uses a lot of early days SM ,
:seems very high power, I suppose for the situation if all 118 relays are
:active at the same time plus CRT plus floppy drive.
:-12V,1A
:+12V, 3A
:+5V,12A
:and a separate +5V,5A
:I'll have to confirm this ps does not require a load to start up, unlikely,
:but not done so yet , no obvious fuses on main board .
:So far cold checked the smps and nothing amiss on Rs,Cs or large active
:Uses UC3842 supervisor, plenty of data, so should be able to confirm the
scillator part of things easy enough.
:


Have had similar symptoms form older SMPS which have lain dormant for years. I
would look for faulty components around the 3842. Usual things such as electro
caps and you may find a high value startup resistor open circuit.