GA-MA785GM-US2H Continuous long beeps at POST

[Daniel42]

Hi All.  I just replaced mb and cpu in a four year old home-built PC.  I put in a GA-MA785GM-US2H and an Athlon II X4 640.  I get no video signal at all, and continuous long beeps on the system speaker.  According the manual it's a bad or missing video card, but this has onboard video.  So I'm thinking dead mb.

But... the power supply I'm using is 4 years old (Antec Earthwatts EA-500) and only has a single 2x2 12v connector.  The mb has an 8-pin 12v connector but the manual seems to imply that it's compatible with 2x2 connectors and that pins 1, 2, 5, and 6 are unused in that case.  It's not very clear, though.

So my question is... Does this sound like a dead board?  Or is it a power supply issue, and I need one with either a 2x4 connector or two 2x2s?

Thanks,
Dan

[absic]

Hi there,

I have to say, from your description, that the PSU is where I would be looking rather than the Motherboard. However, even a four year old PSU should, I would have thought, been able to power up the board without too many problems even only using a 2X2 rather than 2X4 pin ATX connector.

The User's manual for your board says that a PSU of 500 Watt minimum is recommend so it might be worth trying with another PSU if you can.

EDIT: SORRY I MADE A MISTAKE IN MY ORIGINAL REPLY AND HAVE EDITED THIS TO CORRECT MY COPY AND PAST ERROR. 

[Daniel42]

Hi absic.  Thanks for the quick reply.

I just checked again.  The shape of the connector makes it impossible to fit it into the "top half" (pins 1, 2, 5, 6).  It can only go into the bottom half (3, 4, 7, .  Also, the manual states:

1 - GND (only for 2x4-pin 12v)
2 - GND (only for 2x4-pin 12v)
3 - GND
4 - GND
5 - +12V (only for 2x4-pin 12v)
6 - +12V (only for 2x4-pin 12v)
7 - +12V
8 - +12V

and has the top left pin as 1, bottom left as 4, top right as 5, bottom right as 8.

Thanks.

[Dark Mantis]

Actually as far as I am aware both connectors fit in both sockets. Just one has to turn to fit.

[absic]

Yes, sorry Dan,

I looked up the wrong manual when I replied earlier, sorry about that and you are correct, on your board it is the lower 4 pins.

[Daniel42]

Thanks, guys.  So does it still sound worthwhile to buy a new PSU and give it a try?  Is this the usual continuous-long-beeps cause?

Dan

[Dark Mantis]

Certainly can be because if the power is low it won't provide enough for the GPU and so it will give the same beeps as if it is not installed. Also at four years old it has lost a fair portion of it's original output.

[absic]

Hi Dan,

I would be surprised if it is the motherboard at fault but that doesn't mean it isn't.

It is really difficult to say, go and get a new PSU. If you haven't got a friend or another PSU that you can use to test the motherboard then you are stuck really. A new PSU will probably solve the problem but, if your motherboard still doesn't start then you have spent money you didn't really need to.

If it was me I would get another PSU of at least 650 Watts.

[Dark Mantis]

If it was me I would get another PSU of at least 650 Watts.

I would also take that approach if it was me. Try and get one with a single 12 v line.

[Daniel42]

Thanks for all your help, guys.  I'll let you know if the new PSU helps.

Dan

[Daniel42]

Nope.  Didn't help.  Same continuous long beeps.

[Dark Mantis]

Have you checked the power connections to the GPU card?
Can you now fit both 12v connector blocks to the  motherboard?
What PSU did you get?

[Daniel42]

It was a Corsair 600W.  It has a 2x4 12v connector.  Also, I've tried using the onboard video only and also with a video card (with the 6-pin connected).  I keep getting the same results.  I even tried swapping out RAM to see if there was a bad one.

[absic]

OK can we take a step back please?
Could you post back with the Revision number of the Motherboard as there are 4 versions of this board.

[Daniel42]

Hi absic.  It's rev 3.3.  And the PSU is a Corsair GS600

Thanks.