Sony D-5 - Notes on Replacing IC801 (Model D-5 Only); Caution on DC-DC Converter Replacement

D-5/D-50
NOTES ON REPLACING IC801 (MB88541-120M)
(MODEL D-5 ONLY)
CAUTION ON DC-DC CONVERTER
REPLACEMENT
Be sure to check PLL free run frequency when
replacing the DC-DC converter. (Refer to page 36)
DC-DC converter —5V output voltage changes when
the DC-DC converter is replaced, causing PLL free
run frequency to change.
Part of the program and the clock frequency have
been changed on this model’s microcomputer.
(Old) (New)
MB88541-120M mi = =MB88541-124M
clock frequency: 1.2 MHz clock frequency: 1.3 MHz
Reference:
Converter Output Voltage Variation
The repair IC supplied for IC801 is a new type of
MB88541-124M. Therefore, when replacing IC801
on a set with serial No. up to 104,000 which uses the
old microcomputer (MB88541-120M), be sure to
change resistors R513, R809 as shown below.
Conditions Specifications
mechanical
voltage
+5 V output: DC +5.2 V+ 50mV
DC +5 —12V —5 V output: DC-5.2 V + 50 mV
Parts to be replaced:
metal film resistor (chip),
20 k2 5% 1/10W
metal film resistor (chip),
9.1k2 1% 1/10W