Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
I just reread "Chas'" post and noticed him mentioning the possibility of a short shutting off the PSU.
If that were the case, wouldn't it show a low voltage on one of the pins?
arcman49
New Member
Last Activity: 08-31-2017, 07:46 AM
Joined: 03-31-2016
Location: Delafield, WI
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
For the hell of it, I picked up this cheap 4-digit diagnostic card: [url]http://www.ebay.com/itm/380831560767[/url]
Plugged it into a PCI slot and powered up the PSU. There were four dashes on the readout.
The -12v, +12v, +5v, +3.3v and the 'CLK' LED's came on. Neither the 'IRDY' nor the 'FRAME' LED lit. When I pressed the reset button on the MB, it's corresponding LED lit on the card.
Pressing the 'power' button on the MB did nothing. I also tried another PCI slot and...Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
One last shot before I give up and toss this thing...
Do you think one of those cheapee PCI diagnostic cards would give me any useful information?Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
Oops... I made a mistake on U16 pin 5. It's correct at 1.2v. Sorry for wasting your time on that one. All voltages on U16 are proper. I did check the others and Q37 base is .662v, Q38 gate is 5.2v and the cathodes on D17 & D27 are 2.6v.
As to the SYS_PWRGD, R216 is 3.4v.
Pretty much everything on page 27 checks out ok voltage wise except U4 pin 8 which is 12.4v. The schematic shows 5v.
U1 - Pin 1 = 3.4v. Pin 4 = .8v. Pin 5 = 2.5v.
U4 - Pin 1&2 = 5v. Pin...Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
Thanks for taking the time to help out. In the meantime, the other M/board arrived so the HTPC is now working again. But, if there's any chance of fixing the MSI, I'm willing to put in the effort.
Ok, the package type info helped and I found all of the chips on page 27.
I see, for example, SYS_PWRGD has a '15' after it. Or, PWR_OK has a '26,28.35' in front of it. What do these values mean?
On U16, I can see the v out voltages 1.2, 1.25 and 1.8 but on U1 is pin 5 actually...Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
SYS_PWRGD is 2.6v (system on)
PWR_OK is 4.5v (system on)
VCORE_EN# is 2.94v (system off). As soon as the power switch on the motherboard is pressed, it drops to 7.7mv.
I did check the voltages on the original power supply before ordering the new one and the only one that was off was the -12v, which was -10.79v.. That was with the board powered on.
Since I've never taken any electronics courses, you'll have to bear with me. I kinda wing it as I go.
I...Last edited by arcman49; 04-01-2016, 09:11 PM.Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
Thanks for the reply.
I removed the old and installed a new BIOS battery.
At first I was convinced it was the PS because I put in in another system and it did the same thing on the second and third boot attempt. So I ordered a new PS.
In the mean time I went back and tried that same PS on the second and a third system and it booted multiple times and ran for hours without any problems. The new PS arrived and obviously hasn't fixed the original issue with the MSI board....Last edited by arcman49; 04-01-2016, 09:40 AM.Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
Can't find how to edit my post, so I'll add this...
My question is, if it's not too much of a hassle, which pins do you check these voltages on U7 and U23, what should the voltages be and can it be diagnosed without a scope?Leave a comment:
-
Re: MSI DKA790GX \ MS-7550 v1.21 - Do I have a short on NB_VCC1P1?
Hey Agent24...
Hopefully you're still around. Thanks for the post on this m/board. There may be some hope for me.
I have the same board and the same problem except It will power down by holding the switch. Fans and drives power up. CPU makes heat. No display on either the integrated or PCI vga.
My question is, if it's not too much of a hassle, where do you check these voltages on U7 and U23 and can it be diagnosed without a scope?
Thanks.
Lee H....Leave a comment:
No activity results to display
Leave a comment: