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Old 3rd January 2013, 06:47 PM   #1
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Default lepai lp-2020a+ doesn't turn on, no relay click

hello, I just got one of those lepai lp-2020a+ amplifiers because of the reviews people have given it for its sound quality and am having problems with the relay not clicking on. the blue light is on, but the amp is dead silent. I listened to it on one of those wal-mart scosche HD speaker boxes with 2 6-1/2" speakers in it for about five minutes and it sounded great, then it shuts off and never turns back on . i am using a 12v 20ah SLA type battery to power it.

WHAT HAPPENED? Did the relay quit working or something?
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Old 3rd January 2013, 11:16 PM   #2
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anyone?
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Old 4th January 2013, 04:11 AM   #3
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UPDATE.

I just got through opening the case and I found cold solder joints at the legs of the heat sink posts where the solder didn't properly flow (which in their own right takes a lot of heat to properly flow the solder). Both joints were so loose that I could easily rock the heatsink back and forth. Pin 28 of the ta-2020 ic is Pgnd1 and it connects to ground through the heatsink (which had the 2 bad joints).

After the amplifier shut itself off, I resoldered the joint, but still to no avail.

Is it possible that the ic fried when it was straining for more power through pin 28 and the bad joints at the heat sink? I recall that I turned it up loud before it quit (i was able to use the amp for five minutes total before it quit)?
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Old 4th January 2013, 08:08 PM   #4
Bare is offline Bare  Canada
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Unlikely, as those soldered joints are only a cheap substitute for screws attaching the Heat sink extrusion to the pcb. Nothing electrical at all.
Your copy seemingly came pre broken.. Gotta Love that famous Chinee quality.
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Old 4th January 2013, 10:11 PM   #5
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Quote:
Originally Posted by Bare View Post
Unlikely, as those soldered joints are only a cheap substitute for screws attaching the Heat sink extrusion to the pcb. Nothing electrical at all.
Your copy seemingly came pre broken.. Gotta Love that famous Chinee quality.
You got that right. What I have noticed with these is that people either have GREAT experiences with them, or like me, get an ABSOLUTE DUD.

Luckily the person who I ordered this amp from is sending me a new one for free. Now I will have two of these .

That reminds me: Is it absolutely necessary that the heatsink have a connection to the ground plane and for me to check that those two legs have a proper connection? I am asking because the only connection that pin 28 has is through the heatsink itself.
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Old 5th January 2013, 04:43 PM   #6
Bare is offline Bare  Canada
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That sounds an odd configuration.
Don't think it likely. But then Lepai did all manner of foolish stuff.
It Ain't the Tripath circuit... enough said.
Frankly I looked at it for you.. briefly.. but can't be bothered to suss out what those fools cobbled together.
My brain is still reeling from building a point to point Tripath circuit using a 'Genuine' Tripath chip.
I've had more than enough lepai nonsense.:-)
Trashbin (seriously) the broken one on the first successful fire up of the replacement.
Nothing there worth hanging onto imo.
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Old 6th January 2013, 12:45 AM   #7
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Quote:
Originally Posted by Bare View Post
That sounds an odd configuration.
Don't think it likely. But then Lepai did all manner of foolish stuff.
It Ain't the Tripath circuit... enough said.
Frankly I looked at it for you.. briefly.. but can't be bothered to suss out what those fools cobbled together.
My brain is still reeling from building a point to point Tripath circuit using a 'Genuine' Tripath chip.
I've had more than enough lepai nonsense.:-)
Trashbin (seriously) the broken one on the first successful fire up of the replacement.
Nothing there worth hanging onto imo.
OKEY DOKEY

I'll be using the old unit's terminals, rca jacks, the black metal case, etc though for my next DIY audio project where I etch a better board MYSELF. I've made the "mosfet 50" amplifier that pioneer uses for their headunits from scratch before using a tda-7850/pal-007a ic and a gootee board. They are actually REALLY SIMPLE amps to build with only about 10 parts and sound GREAT. Run them on ~17v DC and use BIG power capacitors (10,000+ uf), and they almost double their output versus @ 12v (just put a bigger heat sink on it, though).

thanks for the input.

Last edited by thebestofall007; 6th January 2013 at 12:48 AM.
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