Lepai LP-2020A+ & Lepy LP-838 

I own a Lepy just like yours and works fine

0:37 (Lepy) vs 0:42 of the Lvpai.. The CENTER PIN of the 12vDC input socket of the Lepy - is of a smaller size - thus the larger HOLE in the power cord plug - MISSES the smaller center pin - hence - Ooops again - no DC power at the input - hence it will NOT turn on. One must always (ALWAYS) correctly size the input center pin on the DC socket - to the HOLE in the plug .. Not every 12v DC power cordset - has the exact same center pin / center hole - & thus (just having) one power adaptor doesn't always "work" .. I would try different sized power plug "pin combinations such as 2.1 mm 2.5 mm & maybe even larger or smaller center hole/pin combinations to ensure the power IS getting past the input socket..

Oh dear - !!! Mama never told you to LOOK before you LEAP (or in this case Lepy) The 3.5mm Audio Input on the Lepy - is ON THE FRONT dear boy. Check it out - again - at 5:04 As - oops that MP3 input (on the FRONT of the Lepy) is the 3.5mm audio input that the Lvpin - had - (but it's on the FRONT .. not the back, hence absolutely no need - for a 3.5mm socket to 2x RCA plug adaptor cordset))

I came to see about these amps but while at it, what camera did you use to record the video? The quality is insane :)

Easy, check the power plug, I could tell that by the sound it made when you pluging it in.

I do own a 2020A+ powered by a 12v 5A power supply. With a Pioneer BS22-LR sounds way better with 5A than a 3A power supply

Lepy from Ali Express uses a 20 volt 5amp power suply

The front is out/ in

Leyp lp838 need from Bangladesh. Plzz

8 mins to prove that 1 unit works & 1 doesn't you've got too much time on your hands!!

LP 838, can you use a 12volt,20 amp dc power supply