Trouble booting a Dell Precision T5810 motherboard

I’ve connected the motherboard to the 24 pin power and 8 pin power but all I get is spinning fans and a black screen. I know that dell uses proprietary connectors and I’ve hooked up the 24 pin connector according to the T5810 diagram here: ht tps://docs.google.com/spreadsheets/d/1kZ8F58wlsadiN7k6XfQcABUscF71HVkdeenmGOMz3Lk/edit?usp=sharing. However I did not provide a -12V power pin.

The GPU fan and CPU heatsink fan spin, but I get no video output. The motherboard has no led’s so there seems to be no way to debug whats wrong.

Does anybody know what I might be doing wrong?

@catsay Do you have an insight into getting a T5810 motherboard to boot without the original PSU and case?

I don’t know exactly what is wrong but there could be a few things to check out that come to mind. First, if you haven’t already you can try breaking things down to bare minimum such as 1 stick of RAM, and nothing but keyboard and video plugged into the rear. I don’t know if you are using fans connected to the motherboard headers, but if not I’m not sure how it might react to that. It looks like there is a spot to solder in a small speaker if you are confident enough in your soldering skills. The int_speaker header might also be for the same thing.

I didn’t follow your link, but your description says 8 pin and the connector appears to have 10 pins, so that might be worth investigating if you haven’t already done that.

Last year I had an i5 - 6500 given to me that flat out refused to work after multiple tries at cleaning with alcohol and reseating. Eventually after giving up for months I hit it with an eraser on the pads and now I’m using it to type this post. If you have a different graphics card you might want to give that a shot. I’ve had issues with some cards simply not playing nice with specific motherboards. I have a few GT 720’s laying around that are pretty reliable at working in everything I’ve thrown them in. You might also want to check the amp output on the different rails of the stock PSU’s specs and compare to your own. Occasionally higher wattage PSU’s can still have one rail be a bit mediocre where the OEM PSU might be lower wattage but designed specifically for the task. Hopefully one of those helps you out, good luck!

I’ve tried it with 1 ram stick, video card, and keyboard but same result. Not sure about the speaker part unless it gives me some kind of beeping error code. But the documentation only lists led blinks for error codes.

As for the 8 pin vs 10 pin, the last 2 pins (that I don’t have connected) are connected to the 2 pins right before it so adding another 2 pins shouldn’t change the results.

Think I’ll try another graphics card if I can get my hands on one. The eraser on the pads seems like a good idea too.

For the power supply I’m using one of box power supplies that delivers 5v and 12v, and I’ve wired those to the respective pins on the chart I linked in my first post.