Preset Memory Disappears

INSERT CASSETTE TAPE
1. Can cassette tape be inserted in the tape player?
OK: REPLACE RADIO RECEIVER ASSEMBLY

NG: Go To Next Step
INSPECT FUSE (AMP, RADIO)
1. Remove the AMP fuse from the engine room junction block.
2. Remove the RADIO fuse from the cowl side junction block RH.
3. Measure the resistance of the fuses.
Standard resistance:

Below 1

NG: REPLACE FUSE

OK: Go To Next Step
CHECK WIRE HARNESS (STEREO AMPLIFIER - BATTERY AND BODY GROUND)
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go To Next Step
CHECK WIRE HARNESS (RADIO RECEIVER ASSEMBLY - BATTERY AND BODY GROUND)
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: REPLACE RADIO RECEIVER ASSEMBLY