Sony ICF-SW7600GR Multi Band World Receiver Radio

An icon among the amateur radio...

 Step by step disassembly.

Remove the 5 start screws in the back.
The back and front covers are free to be removed by gently push the four plastic claws on the back cover.


The chassis - back side.

The chassis - front side.
The plastic keyboard key assembly was removed by pulling it out, leaving the key switches visible.

The chassis - front side detail.
Back supply capacitor: 2200uF / 5.5V. It is enough to maintain the clock operation for at least one minute while replacing the AA batteries.

8 Ohm / 0.5Watt Loudspeaker removed and terminal wires unsoldered.
It is secured by two plastic claws.

Key Board assembly removed from the front side of the plastic chassis frame.
The board is secured by two plastic claws.
Gently pull the flat cable from the connector.

 Plastic chassis frame - Front side ( Key Board assembly was removed).
 The flat cable interconnecting the Main board and the Key Board is visible in the central zone.

  Plastic chassis frame - Back side ( Key Board and Main Board assemblies were removed)

Main Board assembly removed from the back side of the plastic chassis frame.
It is secured in place by four plastic claws. Push them gently to remove the board. 

Main Board assembly detail - right side.
"X201" 55.390MHz AM OSC2 crystal visible in the central zone.
"IC203" CXA1522 Pre/Power audio amplifier IC in central bottom zone. 

 Main Board assembly detail - left side.

Main Board assembly detail.
"XF101" AM IF1 55.845MHz filter in first plane.

Exploded view.
After reassembling, the radio worked as nicely as before.

Olivetti SC-2000 calculator

HP-12C Platinum Version 02 calculator

This is the two CR2032 3V button cell model.

Self Test procedure 1.
Power Off.
Press g + ENTER + ON;  Release  g + ENTER; Release ON: Displays "1.L 2.C 3.H 4.Cpu"

 

Press 1 (LCD test): Displays all LCD segments ON.

Press 2 (System test):  Displays "Che - - 564Ah"  (ROM Checksum?)

Press ENTER: Displays "Ver 02"   (Platinum Version 02?)

Press ENTER: Displays C  2004  hP"   (Copyright 2004 HP?)

Press 3 (Keyboard test): Image not available. 

Displays all all LCD segments ON and will shut down them when pressing the corresponding keys)

Press 4 (CPU speed): Displays "3941092   h2"   (CPU speed of 3.94 MHz ?)

The value will change in the last 3 digits between test runs.

Self Test procedure 2.
Power Off.
Press  / + ENTER;  Release  / ; Release ON  (Keyboard test):
Press all the keys from left to right and from top to bottom.
At the end will display "12".

 

Self Test procedure 3.

Power Off.
Press  x + ENTER;  Release  x ; Release ON  (System test):

It runs for about 25 seconds and then shows all LCD segments ON.

This is the two CR2032 3V button cell batteries installed in parallel. 

How fast is the processor? 

Ref. information here:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv019.cgi?read=168545

Quoting Gene Wright:

Enter this looping program. Press:

shift P/R

shift CLPRGM

+

shift GTO 001

shift P/R

1 ENTER ENTER ENTER ENTER CLX
shift GTO 000

R/S and let it run for 60 seconds. The number in the display is the important one. 

My calcyulator gives me a total count of about 1400.

So it doesn't seems to be using the faster ARM processor...

Current comsumption:

Powered ON, Idle state: 10uA

Powered Off: 0 uA

 Running the looping program from above: 1.4mA

Texas nSpire Clickpad CAS calculator