Grundig KSC 35 radio clock - teardown and repair

Small radio with clock and alarm, quite typical in form and functionality.

FM PLL tuner. All functions controlled through pushbuttons.

10 station presets, 16 volume levels (including 0/mute).

Retail price: somewhere between $15-$20.

No signs of life when received and as it weights literally nothing I though at first that this was just an empty shell.

 External switch mode power supply, 5V/0.55A.

2 AAA cells for clock and station memory backup. Measured current consumption: 10 uA with some hard to measure spikes every second. This is quite reasonable and allows leaving cells inside even if radio is unplugged for a long time (some older radio clocks consuming few mAs from 6F22 battery might actually deplete it in one day when unpowered).

Quite easy to open - four screws at the bottom (two hidden under rubber feet) and few small latches. Easy to open without leaving any marks.

7-segment LED display - 4 digits and few extra LEDs to signal alarm state. This is also main board of the device.

Reason of failure: buttons board broken in half. Given factory-new device state I would assume that this was transport accident.

Extra screw holes might be a sign that same shell was also used or intended to be used with different electronics, maybe leaving less empty space inside.

Radio chip: 1580H - cannot find documentation.

Clock/control - unknown blob.

Audio amplifier: 8002A.

Board was glued together with epoxy glue and traced repaired with wire and solder.

To strengthen the board I've glued steel U-shaped rail the edge (probably part of laptop optical mechanism in previous life). Not too elegant but probably stronger than originally.

Cable strain reliefs (heat shrinking tubes) were added to power cord and antenna.

Audio quality is not impressive - I guess typical for this class of equipment.