Troubleshooting MK133 - Only one switch (SW1) works


I purchased the Game / Quiz show buzzer circuit kit MK133 from a US dealer. I planned to use the kit with external push buttons, external slide switches and LEDs and so I soldered wires to LED connections and slide switch connections. Used the push buttons supplied with the kit only for testing the circuit.

I soldered all the components, soldered wires for LEDs and the on/off switch and connected the battery. I also plugged the push buttons that came with the kit to test my connections. I ‘turned the system on’ by shorting the wires for the on/off switch. When I press the switch SW1, the LED1 wires have a voltage between them as measured by the multimeter. I can reset by pressing the reset push button to reset the voltage to zero. But push button switches SW2 through SW4 have no effect on LED1 through LED5. I checked all the connections and polarities of diodes, they seem to be fine though my soldering is kind of sloppy. Any suggestions on how I can troubleshoot this/ I could not find any detailed instructions on your website.

Thanks for any help.

Most likely an assembly problem, due to poor soldering.
Please test the unit ‘as-is’ before applying external parts such as leads/buttons/leds etc…
If you can provide LINKS to SHARP and HI-RES pics of both solder and component side, we can take a look for you.