IBM System/360 2050 User Manual

Marginal Voltages
Progrcrn
Program
Normal
Ch CPU Local Storage Main Storage S toroge Prott>C r
Section
Description
Voltage
6M1 6M2
6TC 6VAR
56 XY 60Z Vsl Vref
Number
+6,0v
+6.0v Opt
Opt
Opt
Opt Opt
l .4v
+0.5v
+0.5v
±5%
±5%
±4.5% ±4.5% ±6%
• 10%
-0.5v
-0.5v
MIDAS
CPU Tests
l Poss 1 Pass
5340X
Diagnose and
1 Pas1 1 Pass
5341X
ErTOr Circuits
5342X
E381X
60 Cycle Int Timing
1 Poss l Pass
E383X
50 Cycle Int Timing l Poss l Pou
F38FX
Meter Timing 1 Pass 1 Pass
5391X thru
Main Storage
1 Pou 1 Pass 1 Pass
S397X
Tetts
5066
53C1X
Local Storoge 2 Min
2 Min 2 Min
53C4X
Bump Storage
2 Min 2 Min 2 Min
!---·-
I-·
·--
E3C9X Storage Protect
2 Min
2 Min
2 Min
2 Min
E421 x thN
Mpx Channel l Poss 1 Poss
E426X
1.Js;ng 1442
E428X thru Mpx Channel
1 Poss 1 Pass
E42BX Using 2540
E441 X thru Sri Channel
1 Poss 1 Pou
E446X Using 2400
Each Channel
F4DOX Channel-to l Pass 1 Poss
F4D1X
Ch..,nne I Feature
F4E1X
Direct 1 Poss 1 Poss
F4E2X Control
5F01X 1~10 Emulator
1 Pass. 1 Poss
5F02X Instructions
~-
1410 Emulator 1 Pass
l Pass
5F04X
Ch Translators
5F21X 7074 Emulator 1 Poss
1 Pass
5F23X thru Instructions
5F2AX
5350 ROS R;pple 1 Poss I Poss at limits of .. 12 ROS voltage
FIGURE 50. MODEL 50 DIAGNOSTICS
Flashing Lights
AAAAAA and 555555 in IAR alternating every four
seconds indicates output device not ready.
FFOOOO and OOFFFF in IAR alternating every sec-
ond indicates crisis.
MARGINAL CHECKING
Marginal checking is a technique used to detect the
marginal operation of the most voltage-sensitive
circuits in the system. These circuits have nominal
levels of voltage and current at which they are de-
signed to function. Each circuit operates within
certain margins (reir.ilator output voltage limits
above and below the nominal rating). However,
aging and other factors cause a gradual deteriora-
tion in the operating characteristics of the circuits.
By raising and lowering the regulator output voltage
within the design margins, it is possible to inspect
all the circuits powered by that voltage. On the
basis of this inspection, any circuit approaching a
failure condition may be replaced. This type of
check is made periodically as a preventive-mainte-
nance technique. Marginal checking is useful also as
an aid in locating operator-reported failures.
Costly down time and many trouble calls can be
avoided by using marginal checking to make failures
less intermittent and more recognizable.
Maintenance Features (3/71) 75

IBM System/360 2050 Specifications

General

Brand	IBM
Model	System/360 2050
Category	Computer Hardware
Language	English