The regulators seem fine, the only off results are as follow:
– U5 input 4.81V
– U6 input 4.78V
– U13 output 2.49V
– U14 output 1.19V
Are any of these significant? Other than those four, all inputs/outputs are bang on the expected voltages.
The ground connection for the audio board is good.
Using USB blaster I wasn’t able to detect the hardware. The JTAG debugger says incorrect clock value – is that of any use?
How do I measure the output clock of the oscillator?
One final observation, when doing these tests I notice that the LCD backlight does come on when the unit is powered on, but only very faintly.
Thanks again for your help.