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Had a Line 6 MM4 come in.
Would not power on.
Checked all of the voltages, which where good.
3.3Vdc came up when a cord was inserted into the input jack.
Pressing any key did nothing.
Tried a master reset at power On (Hold A and D keys down, power On)
Nothing doing.
Scoped the crystal. Oscillating fine.
OK. Now what.
I used a 10X magiifier a looked at the main microcontroller.
Some of the solder pads looked iffy at best.
So I hit it with my Weller 750 degree heat gun and then popped it in the freezer for 10 minutes.
Lo and behold!
It works.
Thought I would pass this on.
)
Here is a voltage measurement schematic.
And a brief of how the power supply functions from a gentleman in Scandinavia.
Would not power on.
Checked all of the voltages, which where good.
3.3Vdc came up when a cord was inserted into the input jack.
Pressing any key did nothing.
Tried a master reset at power On (Hold A and D keys down, power On)
Nothing doing.
Scoped the crystal. Oscillating fine.
OK. Now what.
I used a 10X magiifier a looked at the main microcontroller.
Some of the solder pads looked iffy at best.
So I hit it with my Weller 750 degree heat gun and then popped it in the freezer for 10 minutes.
Lo and behold!
It works.
Thought I would pass this on.
)Here is a voltage measurement schematic.
And a brief of how the power supply functions from a gentleman in Scandinavia.
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