28 Jul 2019, 12:35
Received a game watch from Argentina recently. It has been worked on before after some likely battery damage. It's a two-LCD watch, the time functions and game backgrounds are on a black LCD, the game sprites on a green/filtered LCD.
When a battery is inserted the watch seems to cycle then turn off (odd combinations of LCD segments are lit during the process).
If game mode can be selected during this cycle process, the game will play flawlessly. Within a few seconds of the game finishing, if a new game isn't started, the watch will also turn off.
Here's a video - it's a bit long so forward through the boring stuff - showing what it does. Any clues as to what may be causing this?
On the circuitboard, traces have been checked and tested ok (as far as I'm able). Components removed and the board cleaned, and components reinstalled (I changed the crystal for a new one, but the behaviour is the same). The only components are two transistors (D18 and P-6) three capacitors (two of which are only reading 0.05nf and the other around 100nf) and a resistor (20khm).
Advice, or things to check for would be appreciated; it could be a IC of course, but I'm hoping it isn't.
https://youtu.be/4w6gKAeqrJY
When a battery is inserted the watch seems to cycle then turn off (odd combinations of LCD segments are lit during the process).
If game mode can be selected during this cycle process, the game will play flawlessly. Within a few seconds of the game finishing, if a new game isn't started, the watch will also turn off.
Here's a video - it's a bit long so forward through the boring stuff - showing what it does. Any clues as to what may be causing this?
On the circuitboard, traces have been checked and tested ok (as far as I'm able). Components removed and the board cleaned, and components reinstalled (I changed the crystal for a new one, but the behaviour is the same). The only components are two transistors (D18 and P-6) three capacitors (two of which are only reading 0.05nf and the other around 100nf) and a resistor (20khm).
Advice, or things to check for would be appreciated; it could be a IC of course, but I'm hoping it isn't.
https://youtu.be/4w6gKAeqrJY