Re: Benq G2255 doesn't power on - amber power light when plugged in - part 2
Nothing jumps out at me with your readings. To see if the power board or t-con are zapping the main board, you need to give both the turn on signals from the main, then measure each pin on the connectors to see if you are getting a voltage back that would damage the main. Many of these ICs have a few pins that are 5V tolerable, and I think the lcd_aware is one of those on your chip. So, that would be the only one that I could think of that would be able to handle a higher voltage.
To give the turn on signals, you'll have to jump 5V to the lvds connector as I mentioned above for the t-con. You'll have to jump the same pins on the power connector that you jumped when you were testing the power supply. This time you need to jump the resistors from the back of the connector, so that it can be connected to the main. When you power on, check all pins on both to see if you are getting anything that doesn't belong on the pin. You can also probe each pin on the chip to see if you find something that doesn't belong (i.e. voltage on a ground pin, or a higher voltage than expected on other pins). You'll have to follow the schematic as you are probing the pins. I've already mentioned the transistor that turns on the 5V to the panel. You really need to make sure that it is not shorted, and sending 5V back to the chip. For that matter, I would check every transistor and diode on the board.
This is the only way that I can think of to make sure that the t-con and power supply won't zap a new main board as soon as you install it. You do have another chip, so you could try it. This time I would go through the tedious process of checking continuity pin to pin to make absolutely sure that you don't have any solder bridges below/behind the pins that are difficult to see. Once the chip is in, leave all connectors disconnected. Jump only the ground and standby voltage to the main, then check everything.
Nothing jumps out at me with your readings. To see if the power board or t-con are zapping the main board, you need to give both the turn on signals from the main, then measure each pin on the connectors to see if you are getting a voltage back that would damage the main. Many of these ICs have a few pins that are 5V tolerable, and I think the lcd_aware is one of those on your chip. So, that would be the only one that I could think of that would be able to handle a higher voltage.
To give the turn on signals, you'll have to jump 5V to the lvds connector as I mentioned above for the t-con. You'll have to jump the same pins on the power connector that you jumped when you were testing the power supply. This time you need to jump the resistors from the back of the connector, so that it can be connected to the main. When you power on, check all pins on both to see if you are getting anything that doesn't belong on the pin. You can also probe each pin on the chip to see if you find something that doesn't belong (i.e. voltage on a ground pin, or a higher voltage than expected on other pins). You'll have to follow the schematic as you are probing the pins. I've already mentioned the transistor that turns on the 5V to the panel. You really need to make sure that it is not shorted, and sending 5V back to the chip. For that matter, I would check every transistor and diode on the board.
This is the only way that I can think of to make sure that the t-con and power supply won't zap a new main board as soon as you install it. You do have another chip, so you could try it. This time I would go through the tedious process of checking continuity pin to pin to make absolutely sure that you don't have any solder bridges below/behind the pins that are difficult to see. Once the chip is in, leave all connectors disconnected. Jump only the ground and standby voltage to the main, then check everything.
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