Crown PSA-2 - Page 106

SA2PSA2020780
SAZ/PSAZ Intermittant Instability
10000-11343 (PSA-2) 111947-112551 (SA-2)
On the output of every SAZ/PSA2 Amplifier is a RLC output terminating network
(LIO0/L200, R125/R225,C119/C219). It has come to our attention that because
of the wrapping and soldering techniques used in production an instability
problem can develop. The following are two possibilities to look for:
1.) The leads of the 2.7 ohm 10w resistor were cut too short
sa the resistor sits rather snug on the mother board
(located inside chassis). If excessive pressure is used
to install the output modules, the resistor could be damaged
(the resistor lead breaking away from the resistor itself.
Replacement of the resistor is in order.
CPN DESCRIPTION
Part (3813-0 2.7 ohm 10w
2.) The torreid coils (L100,L200) were produced with the con-
necter leads wrapped to tight. When soldered, the Insula-
tion heats and a break in the insulation takes place; causing
a@ short and eliminating the coil/resistor network from the
circuit. Unsolder the leads from the coil and unwrap one or
more lead windings to seperate the wire ends where the insule-
tion is broken through.
if you have a SA2 or PSAZ that exhibits instability, excessive heating and the
high speed fan turns on between 5-10 seconds after the instability shows itself,
the above may be the cause of the failure. if you have any further questions,
please call or write.
Dave R. Engstram
Product Specialist