The DMM can measure high frequency transformer output can't?

[abdulbadii]

Why can’t this cheap DMM measure the high frequency voltage transformer output inside a switching power supply?
Is it just me or just "the money never lie" does evince?

[xrunner]

Why can’t this cheap DMM measure the high frequency transformer output inside a switching power supply?
Is it just me or just "the money never lie" does evince?

What cheap DMM are you referring to? 

[Brianf]

What does your meter's manual say about the upper limit of frequency for AC voltage measurement?

[jonpaul]

SMPS freq
20khz ?50?100?
1 MHz 10mhz?

For a 120/240 mains the SMPS switches have 360V peak.

most DVM are for mains frequency 50/60hz, the detection is designed to work to perhaps 1 kHz.

Finally making any test, debugging an off-line SMPS requires scope, isolation transformers, current probes.

Your post suggests that your experience is not sufficient for this kind of work.

Jon