On 03/02/18 07:27, Harry Bloomfield wrote:
The Natural Philosopher laid this down on his screen :
No: By and large the chips don't blow, There is usually a chopper
power MOSFET and that is what takes the strain if a diode goes bad.

Replace diode, 450V cap and power FET and fuse and it should work

I agree, but rather than simply replacing the cap, I would test it first.

If you have the ability to do so, yes, and can spare the time..


I'd estimate that a driver would cover all those parts - and take less
than half an hour to do.

Why bother testing?

When years ago I worked in a comany producing rather shoddy audio power
amps, the girls who fixed them had zero theoretical knowledge. They were
taught to replace all of the output transistors, the drivers, the fuses,
and the power resistors if they looked burnt.


about 15 mninutes with almost completely unskilled labour...

The transistors were then tested later by an engineer on a transistor
tester, and good ones put back as 'replacment parts' in the repair
department.

I cant recall whether that tester was not in fact a simple home made
device checking that they werent short circuit and exhibited some gain...


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No Apple devices were knowingly used in the preparation of this post.