Here's another USB power adapter I have that isn't working properly. Well, everything works except the USB port.
I changed the DIP-8 MC34063 chip but it still doesn't work.

Could someone take a quick look at it and tell me what you think could be the problem?

There is a diode and a few capacitors, some resistors and the chip. Pretty simple. How would I diagnose this board and find the problem?
Do I need to remove the diode from the PC board to test it?

Thanks!
Click to see up close details

 

You're better off downloading the datasheet for it, and that will give you a circuit diagram, looks like its used as a step down converter, pins 1,7,8 are linked together.

 

Thanks Dave. Do you mean the datasheet for the chip of the entire USB device? I can get a datasheet for the chip...but not for the entire device.

 

The chip datasheet. Here is an application for step down, compare the values with your pcb, see if it is the same circuit.