SX280 not powering on; amber blips once, da-2 fades off

[mazade]

Well, here again with another "it's not working after I recapped it, thinking I had this one in-the-bag".
SX280 Phrizbee, I recapped it's twin sitting at the same work-station only a month earlier, worked like a dream(and still is).
My friend who got to this current problem initially opened the case to find the chipset-heatsink-clamp-hold-downs !?desoldered?! from the motherboard, wow.
Well, on site, he re-soldered the spring-clamp-hold-dowm to the board thinking that would fix the issue of it not turning on, and it still didn't work....
*he doesn't play in the bad-caps field so it wasn't something he was looking for while performing the hold-down fix*

Anyhow... I get it here, and recap the standard '6mm & above' caps with what appropriate poly's I have from badcaps.net, and fill the others with similar samxon's and rubycon's.
The post-recap issue: plug in the DA-2 power supply... wait a moment... amber power light blips once and then you notice the DA-2 power LED start to fade out, as well as the LED near the center-area of the board. The DA-2 fades to black and doesn't come back, and the computer/board won't even begin to power-on.
Unplug the DA-2, re-plug, same cycle of blip & fade; doesn't change.

I spoke with my friend... after I sat and freaked out while stripping the board down to make certain it wasn't any one component causing this... he claimed that he saw and experienced the same problem after his attempted fix for the chipset heatsink detaching. *phew* I think...

Has anyone seen/experienced this(maybe even resolved this problem) and/or what should I be thinking about here?
Oh yeah, I have two DA-2 supplies here, both do the same thing, and as far as I'd know they're OK. I also have faith in what Topcat and others say... "they don't fail".

In advance, thanks guys.

[seanc]

Re: SX280 not powering on; amber blips once, da-2 fades off

I have a similar problem with an SX280 I re-capped. Wasn't doing it before I performed the re-cap, it was just unstable.

Plug in a DA-2 power supply.
Orange led on the mobo blinks, as if a short has been detected and it's shut down.
Unplug and re-plug the power supply, it usually works fine or I keep trying it in sucession.

Try it quite a few times and see what happens.

My thought is that the selection of caps I've used are too low ESR.

I've replaced every cap in that PC.

[TCKTMB]

Re: SX280 not powering on; amber blips once, da-2 fades off

Check the solder joints on the heat sync hold down. It completes a circuit and the machine wont power on without it. Do the fans spin up at all?

[midibob]

Re: SX280 not powering on; amber blips once, da-2 fades off

Hi,

I had something similar with a 620 and this was due to a ham fisted bad fitted CPU. In fact some of the socket pins were so mangled it wasn't worth repairing. Changing caps is one thing, a CPU socket is way out of my league as I don't have an SMD rework station.
Hope that isn't your problem otherwise it's probably a write off.

Good luck
Midibob

[seanc]

Re: SX280 not powering on; amber blips once, da-2 fades off

Checked heat sync contacts OK. Reflowed anyway.
CPU socket is fine as far as I can see.

Machine works fine once you get it to keep the light on...

[Agent24]

Re: SX280 not powering on; amber blips once, da-2 fades off

Maybe the chipset got overheated by the heatsink clips coming off?