Good day,
My remote gate stopped working. The company said the main logic board needs replacement. After examining and running a couple of tests, I discovered what looks like a shorted zener diode. Tracing the path on the board it appears to be across a voltage regulator chip (78m05). After reviewing the datasheet for the voltage regulator I thought that it was being used with a zener diode as a voltage boost regulator. However, looking at the layout of the board the "shorted diode" is not connected as in the datasheet. The diode does not have a markings so I am not sure what to replace it with. The 78m05 chip outputs 5v according to the datasheet. I'm assuming that the microprocessor vcc is that. I applied around 1V, 1A after removing the diode and the 78m05 chip to the vcc pin of the d747m_1v3 microprocessor and it drew around 287mA while I eventually raised the voltage to 5v. I believe if the diode in question is used for protection then the circuit may work without it if tested. I have attached some pics hoping that someone can assist me. If I can get a schematic that would be awesome. Thanks for reading my post and I look forward to any feedback.
My remote gate stopped working. The company said the main logic board needs replacement. After examining and running a couple of tests, I discovered what looks like a shorted zener diode. Tracing the path on the board it appears to be across a voltage regulator chip (78m05). After reviewing the datasheet for the voltage regulator I thought that it was being used with a zener diode as a voltage boost regulator. However, looking at the layout of the board the "shorted diode" is not connected as in the datasheet. The diode does not have a markings so I am not sure what to replace it with. The 78m05 chip outputs 5v according to the datasheet. I'm assuming that the microprocessor vcc is that. I applied around 1V, 1A after removing the diode and the 78m05 chip to the vcc pin of the d747m_1v3 microprocessor and it drew around 287mA while I eventually raised the voltage to 5v. I believe if the diode in question is used for protection then the circuit may work without it if tested. I have attached some pics hoping that someone can assist me. If I can get a schematic that would be awesome. Thanks for reading my post and I look forward to any feedback.
Attached Files
Comment