no LED or power on Acer AL1716

[Duncanbest]

Re: no LED or power on Acer AL1716

FYR
https://www.badcaps.net/forum/showthread.php?t=12716

C54 & C56

[bboettner]

Re: no LED or power on Acer AL1716

I am replacing caps on power board, model XAD819AR, for an Acer LCD monitor, model AL1916. The board has been repaired by someone else previously, and I'm concerned that I'm replacing capacitors of incorrect capacitance. All of the repair kits that I have seen have two 1000μf caps listed, but the board I have doesn't have any of those on it. I think they may have been improperly replaced.

I need help locating the correct placement of the 1000μf capacitors on this board.

[Lumberjack777]

Re: no LED or power on Acer AL1716

i've replaced everything except C5, the large cap laying on its side...

It's been awhile since I have seen that board but if I remember correctly the smaller capacitors at C57 and C62 and the other small cap inside the heat sink wall will develop high ESR and maybe bulge. That design is a total heat trap.
You'll need to test CR51 and CR52, and possibly WJ10 for shorts. ORRRRRRRR you can buy a new board for 19 bucks and wait 2 weeks. When the price of caps and component equals the price of a new board I just get a new board. But you can solder on the good caps and it'll probably last a long long time. http://www.ebay.com/itm/TDK-Power-Bo...item3f1ac17fff

Just a suggestion! Good luck! L-J-7

[digidelia]

Re: no LED or power on Acer AL1716

i've replaced everything except C5, the large cap laying on its side...

[retiredcaps]

Re: no LED or power on Acer AL1716

i've replaced all the caps,

In your pictures, it doesn't look like you replaced any of them?

As budm alluded to, does all mean all?

[budm]

Re: no LED or power on Acer AL1716

I would try replacing those two caps first.
You can also run the power supply without having the main board connected, the power supply board is always on the minute you plug it into the outlet, and see if the 12V and 5V are steady.

[digidelia]

Re: no LED or power on Acer AL1716

yeah, sorry about that. here are some pics of the board.

as far as i can tell, the 12v floats around 6-7v. i don't have access to a waveform scope at the moment for a better explanation.

[jetadm123]

Re: no LED or power on Acer AL1716

Well, since there is no schematic and the board is sitting in front of you, the folks that would normally provide assistance are at a slight disadvantage, since they have nothing to look at or reference. Please provide top down photos of the entire power board top and bottom. Use "manage attachments"
to post them.

The ticking sounds like the power supply is trying to start. Possible bad startup cap. Does the 12V output go up to 7V then drop to 0V? Then repeat itself?

[digidelia]

Re: no LED or power on Acer AL1716

also, i have to add, i hear a soft "clicking" when the mains is plugged in. i can't really narrow down where it's coming from

[digidelia]

i'm having an issue with this monitor that uses a TDK XAD819AR power board.

when plugging in the power board to mains, i'm not getting +12v on the 8-pin header. instead i get between 6-7v.

+5v is working.

160v on main cap

i've replaced all the caps, and verified the 12v regulator is working (IC53).

is there anything else i can check? or does anyone have a link to the schematic for this board? i've scoured elektrotanya and none of the service manuals seem to reference this power board.

thanks for any help you can provide!