Sharp MZ-80B - Page 20

Problem (4) No +5V,
Is voltage at the
other output
terminals normal?
IS8pprox.14V
present at pin
15 of IC4017
NO
NO
When R405 is NO
open, does O.2Vpp appear'>='--- ____ ~
at pin 12 of IC401?
Check Q401, 0402
and smoothing
circuit
Problem (5) -5V is abnormally high.
Check
IC201
Problem
(6) +12V is abnormally high.
Check 1C401 and
circuit
of IC401
Check 0301, 0302 and IC 301.
Problem (7) +5V is abnormally high.
Check
0401, 0402 and IC401.
Check F401, T101,
D401,C412,C401
- C404, C407
Check primary
circuit which includes
T101.