Phase Linear 200 S2 Service Manual

Page 2

POWER TRANSFORMER PRIMARY WIRING DIAGRAM

240 VAC 120 VAC
0

BLU g

BLU IYEL LBLU) BLU YEL IBLU}

{BRNJ
BRN ,IYEI.

IF THE PRIMARY VOLTAGE IS CHANGED THE LINE FUSE MUST BE CHANGED AS FOLLOWS:

120 VAC: Use 5 AMP, Type AGC
240 VAC: Use 2V2 AMP, Type AGC

Phase Linear Service Department
20121 48th Ave. West
Lynnwood , WA 9 80 36
Tel.(206)774-8848

(206)774-3571

prepared 10/78
revised 7/81

Page 19

Verify approximately 0.4 VDC, :0.1 V. Adjust'
bias pot R24 as necessary.

6-5.2. Excessive THD Measurement.

a) Excessive crossover distortion: possible shorted
bias transistor; check and replace as necessary.

b) Defective protection circuit: see section 6-3.3.
c) THD analyzer interface problems:

-activate the 80K Hz filter on the analyzer if
it is so equipped; repeat the THD measurement.

-examine the test bench grounding system for
possible ground loops. Ground the analyzer
directly to the ZOOII output ground, not to the
load, scope or meter grounds.

6-6. EXCESSIVE OFFSET
a) Replace Z1.

b) Verify :15 VDC across D9 and D10; replace if
necessary.

c) Replace C2 (lOOmf 6.8V)
Note: refer to section 6-3.1c for further information.
6-7. PROTECTION CIRCUIT MALFUNCTION
6-7.1. Supply fuses open when amplifier is shorted. This
indicates that the protection circuit is not
shunting drive current properly.

a) Check Q7, QB, D3, D6.

b) Check R14, R16, R18, Rl9.

c) Perform current sharing test 6-1.4 to determine if
the current sensing transistors for the protection
circuit (95, 910) are open.

6-8. OUTPUT RELAY MALFUNCTION.
6-8.1. Output relay will not open with low frequency signal.

a) Check 01, C4 on the relay control PCB PL31.

b) Check wiring connections from PL31.

l9