sony: Sony ICF-7600DA - Released revisions
sony: Sony ICF-7600DA - Released revisions
Model revisions
Production started in 1987 and at least three revisions of this model were made during its short production life (production allegeded stopped in 1989):
- Up to Serial Number 7901 - This is the original design.
- From Serial Number 7902 to 62626 - New improved ACG circuit, adding IC7 and removing some of the original AGC components (see Service Manual).
- From Serial Number 62627 to "X" - In 1988.1, the Receiver PCB was changed, namely to replace two electrolytic caps marked as C20 and C83 on the Conductor Side, with SMD round can types installed on the Component Side (see Service Manual Supplement 1)
- Also, the Italian version was added to the existing US, CAN, E, AEP, UK, FR, and AUS versions.
- From Serial Number "X" to "Y" - Somewhere in 1988 or 1989, another PCB revision was done, where two more capacitors were replaced with those SMD aluminum round can types.
- My unit with s/n 104566 have these two additional 10uF 16V SMD round can type electrolytic capacitors installed on the Component Side replacing the original ones installed at the Conductor Side at positions C74 and C76
- With this revision, a total of four SMD aluminum round can electrolytic cap types are seen on the Component Side of the Receiver PCB.
- The Receiver PCB label is 1-597-537-14 / 1-622-118-14.
- These caps are notorious for leaking and going defective after a few years. This is a well known issue that affected several Sony equipment of that era.
Main circuit components
MCU PCB assembly
- PCB printed codes:
- Later units: 1-597-538-12 and 1-622-120-12
- Older units: 1-597-538-11 and 1-622-120-11
- Service Manual 1987.8 pn:
- A-3675-005-A (US, CAN, E) or
- A-3675-006-A (AEP, UK, FR, AUS)
- Service Manual SUPP-1 1988.1 additional pn:
- A-3675-008-A (ITA)
- IC201 UPD1715G-529 MCU with Pre-Scaler PLL Synthesizer and LCD Driver
- IC202 MSM5259GS-K Dot Matrix LCD Driver
- IC203 MC74HC00F Quad 2-Input NAND - Rotary Encoder for Tuning and Time adjust, LCD switching
- IC204 MC74HC00F Quad 2-Input NAND - Rotary Encoder for Tuning and Time adjust
- IC205 MC74HC00F Quad 2-Input NAND - Rotary Encoder for Tuning and Time adjust
- IC206 MC74HC74F Dual D-Flip-Flop - Rotary Encoder for Tuning and Time adjust
Receiver PCB
- PCB printed codes:
- Later units: 1-597-537-14 and 1-622-118-14
- Older units: 1-597-537-12 and 1-622-118-12
- Service Manual 1987.8 pn:
- A-3660-679-A (US, CAN, E) or
- A-3660-685-A (AEP, UK, FR, AUS)
- Service Manual SUPP-1 1988.1 additional pn:
- A-3660-743-A (ITA)
- Q1 2SK238 LW/MW RF Amp
- Q5 2SK238 SW RF Amp
- Q2 2SK508 1st Mixer Amp 10.7MHz IF output
- Q7 2SC2223 VCO(L) SW Osc
- Q6 2SK209 VCO(L) Buffer
- Q8 2SC2223 VCO(H) SW Osc
- Q6 2SK209 VCO(H) Buffer
- Q3 2SK209 2nd Mixer Amp 445kHz output
- Q4 2SC2223 2nd Osc 10.255MHz
- Q16 2SK238 FM RF Amp
- Q25, Q26 2SB624 - Power Control Switches
- IC1 TC74HC138F 3-to-8 Line Decoder - SW band selector
- IC2 TC74HC138F 3-to-8 Line Decoder - SW band selector
- IC3 MC74HC595F 8-bit Shift Register with Latched 3-State Outputs - SW band selector
- IC4 CXA1031M (CXA1019M on -14 PCBs) - FM/AM Receiver
- IC5 LA5003M 9C4 3V LDO Voltage Regulator - +3VDC TR receiver
- IC6 S-81230AG-R8 H5 3V LDO Voltage Regulator - +3VDC +B to MCU PCB assy
- IC7 UPC358G2 (s/n 7902 and later) Dual Opamps - AGC Amp
- RV2 1K Trimmer - AGC adjust
Undocumented proprietary Sony IC's
Some Sony integrated circuits were never publicly documented and were produced to be exclusively deployed on Sony equipment.
The CXA1031M used in this model seems to fall into this category, as it seems to be impossible to find a datasheet where the specifications can be consulted.
Although later in the production cycle of this model, Sony apparently decided to use the common, well documented, CXA1019M IC to replace the CXA1031M listed in the Service Manual.
This is the case of my unit with s/n 104566 and PCB printed codes 1-597-537-14 and 1-622-118-14. I can confirm that the IC4 was not tampered after the unit left the factory, as the soldered pins looks absolutely original.
Also, my unit sensitivity is on par with similar models I have with me.
I didn't check the circuit around CXA1019M against the Service Manual, so I can´t tell where it can replace the original CXA1031M without circuit modification. However, the pinout seems to be identical.
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