Lambda LL Series Instruction Manual page 13

Symptom
2. Unable to adjust out-
put voltage
3. High ripple at line
frequency or twice
line frequency and
unregulated DC output
4. Same as 3, except
intermittent
5. High ripple at. fre-
quency other than
line or twice line
frequency
6. Large spikes at out-
put
IM-LL
TROUBLE SHOOTING CHART (cont'd)..
Probable Cause
Fl and/or F2 open
Series regulator section
open
Open CR8 or, as appli-
cable, CR11 or CR12
Open CR4 or R1
Current sensing resis-
tor open
Aux. rectifier CRl open
Damaged VOLTAGE ADJ.
controls
Series regulator tran-
sistors shorted
Defective main recti-
fier causes ripple at
twice line frequency
Foreign matter fallen
into unit
Oscillation due to defec-
tive component in filter
network
Capacitors C3 and C4 open
Remedy
Replace Fl or-F2; if it
blows immediately, check
for shorted transistors
Q1, Q2 and capacitors C5
and C7, replace as neces-
sary
Check Ql and Q2 for open,
replace as necessary
Check CR8 or CR11, CR12
for open, replace as nec-
essary
Check CR4 and R1 for open,
replace as necessary
Check R7 for open, R6 for
short; R9 for open; re-
place as necessary
Check CR1 for open; re-
place as necessary
Check RS and RIS for short
and/or open; replace as
necessary
Check 01 and Q2 for short
and replace as necessary
Check for open and/or
short CR2 and CR3
Check for loose bench hard-
ware and wire clippings
that may have fallen through
cover
Check for
check for
in C8 and
defective
open C7, C2 and
open and/or short
R14. Replace
component
Replace C3 and C4 as nec-
essary