Hi!
I require your help regarding a problem I’m encountering.
I have a mint condition i-Sobot Humanoid Robot and Controller. The controller turns ON no problem and actually works fine for 10 seconds (LCD display is normal and robot can be controlled). However, after 10 seconds the display goes blank (or only one dark line appears) and the Controller no longer works. If I turn the Controller OFF and then back ON I get another 10 seconds of “play” and so on. There is no change in the length of time it stays ON.
I have:
- Thoroughly cleaned the battery terminals.
- Inserted 3 New AA Alkaline Batteries (they work fine in another i-Sobot Controller).
- Tested the Robot with another Controller proving that the issue is definitely with the Controller.
- Cleaned the Power/A/B Switch with Electronics Cleaner.
- Confirmed that the PCB gets the full ~4.7V of power from the battery case when the switch is ON.
- Replaced the only large capacitor (10V 220mf) on the PCB with a new one.
- Removed the main PCB and cleaned the LCD Display Contacts (on the module and on the PCB) with alcohol.
- Touch soldered any suspicious solder pad connections (those that looked “dry” or had a tiny bit of oxidation)
.
I am not an electrical engineer but suspect it was due to a bad connection or a bad capacitor (possibly a power transistor but I do not see one).
The good news is that it does work but the bad news is that it never works for more than 10 seconds and only after performing a Power OFF/ON reset.
I am hoping that someone here can suggest something for further diagnosis or point me in the right direction. It would be nice if someone was familiar with the i-Sobot but I’m not holding my breath.
For reference I have attached a picture of the main PCB which is basically one-sided (only button tracings and display pad contacts are on the non seen side). As you can see it is in remarkably good condition for its age. The 2 smaller PCBs are the support boards for the 2 joysticks.
Thank you so much in advance for your help!