HP 8200 Not Turning On

[pfisher]

I have an HP 8200 Elite Ultra Slim computer running Windows 7.  After I connect the power to the computer, the light on the motherboard is green but the hard drive status light is a constant green light. The computer will briefly turn on then immediately shut off. After that, I can't turn on the computer. I have removed the computer down to nothing and reseat various parts. I don't see any popped capacitors or any burnt areas on the board. Looking at the board, it looks fine. I don't know what the problem is.  

I am guessing the computer has some type of power overload which would cause it not to turn on.  I am not sure which part would be causing an overload, if any.  I haven't swapped out any parts yet. 

Does anyone have any suggestions?

[mdklassen]

Suggestions:

1. Disconnect the data/power to the disk-drive and optical drive, and reboot.  Does it run the POST (Power On Self Tests) ?
2. Have you tried temporarily attaching a different power-supply?
3. If the motherboard has multiple sticks of RAM, try booting with only one stick connected.

[pfisher]

As I had said before, I removed all components including hard drive, optical drive and RAM.  This computer only has two slots for memory.  I tried swapping them out and tried one stick at a time. I have tried no memory as well.  I tried another power brick. No change.

The computer doesn't invoke POST at all. The computer doesn't stay on long enough to even reach that point. 

Right now, I have the computer down to bare metal.  No RAM, hard drive or optical drive connected.  The only stuff that is connected are the two fans, processor, and card w/heatsink. 

The computer is off. Once I plug in the power, the motherboard light briefly lights up then off and the status light stays a solid green light both fans spin then off and status light remains on.  If I hit the the power button, nothing. Once I unplug the power, the status light goes off. 

[mdklassen]

Your computer: HP Compaq 8200 Elite Ultra-slim PC Product Specifications

was originally shipped with either Windows Vista or Windows 7.

> The computer is off.

> Once I plug in the power, the motherboard light briefly lights up then off and the status light stays a solid green light

> both fans spin then off and status light remains on. 

> If I hit the the power button, nothing.

> Once I unplug the power, the status light goes off.

Like your computer, I have a Lenovo desktop that does a similar "mini-POST" as soon as the electrical power is connected. The fans spin at full speed, for a second or two, then stop.

Fortunately, this Lenovo does respond to a touch of the ON/OFF switch.

To summarize all that you have presented, it's your motherboard, not your power-brick, that has failed.

 Given the "vintage" of your motherboard, it's time to "responsibly recycle" it.

You may be able to use the RAM & disk-drive & optical drive & power-supply with a different motherboard.

[DanR85]

Hello, I'm sorry for the necro bump - but I specifically joined this site to answer this question.

I was working on exactly the same machine - an 8200 SFF that had the same problem. Almost constant HD light, even when the unit was powered down. It would intermittently power on, then shut down again.

I confirmed the problem was not with CPU, RAM, any of the SATA drives or the PSU.

My first solution was to attempt to replace the motherboard, but to my dismay, the problem persisted!

It turns out, after many hours of head scratching and hair pulling, that I was able to power on the unit without any problems if I removed the front panel motherboard connector, and used my screwdriver to short out the power pins instead. This pointed me to the problem: When the power switch was connected to the motherboard header, it was causing instability.

I guess it was causing a short and the board was doing a safety shutdown. As luck happened, I had a similar switch lying around and was able to remove the old one from the front panel and replace it.  The whole front panel is available on ebay for about £10 ($13 USD).  A relatively straight forward job if you're a geek like me, or not too expensive to get somebody else to undertake if you're so inclined.

The front panel is located right in front of an exhaust fan, literally in the path of air flow, so I'd imagine a fair amount of dust an gunk accumulates in the switches over time. Unfortunately, cleaning it didn't do much. A replacement however, solved the problem immediately.

I know this is several months late, I just wanted to provide a potential solution should anybody else find this forum through Google.