Unsolved
This post is more than 5 years old
2 Posts
0
1699
January 5th, 2020 14:00
Optiplex 5050 SFF PSU or mobo broken
TLDR: On the AC180ES-01 power supply in the SFF version of this computer (5050) does the Power Good (grey wire) adhere to the ATX specification? Meaning it supplies 5V only when Power On is shorted to ground? Or should it also be on while on standby. Thanks in advance.
The longer version is this: so I did something dumb. I used the older model SATA power connector on my SFF 5050 and shorted the 3.3V rail to the 12V rail. Why you'd change the connector spec who knows.
Now the computer works when on but when on standby the 5V and 3.3V rails are off. This makes the fan run at full speed when the computer is off (since 12V rail is present but the control is not pulled to ground by the fan controller) and kills power to USB. I'm trying to diagnose the computer to see if it's the power supply or the mobo.
The power supply seems to be fine but I have one question I can't find anywhere. On standby it supplies stable 12V on both rails and when the green wire is shorted to ground it lights up the green light and supplies 5V to the grey wire (Power OK). It also passes the self test on the BIOS. Before I spend money on a new mobo I have to verify that the 5V and 3.3V rails on the mobo don't expect to receive the Power Good signal also when on standby and that's why they don't turn on. In that case the PSU would be broken, ergo the above question.
Also if you have heard of this and know the source of the issue it'd be great. I can do an smd component swap need be.
speedstep
11 Legend
•
47K Posts
0
January 6th, 2020 09:00
All current and even 5 year old models are EPS12v not ATX12v spec'd
The 5050 does not have 5v standby. It uses proprietary power supply not the 24 pin eps12v power supply.
These models get drive power from Regulator on the motherboard. So you permanently zapped/damaged the motherboard.
You can remove the internal power supply and use a MODDIY adapter with at least EVGA 500W unit.
https://www.moddiy.com/products/Dell-OptiPlex-3040-3050-3060-Main-Power-24-Pin-to-6-Pin-Adapter-Cable.html
https://www.youtube.com/watch?v=SCQTj1ei3Ew
<ADMIN NOTE: Broken link has been removed from this post by Dell>
(edited)
gipsonjustin17
2 Posts
0
January 6th, 2020 10:00
I know it doesn't have 5V standby. I'm asking mostly to triple verify.
My theory was that the only way it could be the power supply was if the regulator in the mobo waited for the power good signal before powering on on standby as well. And the circuitry that pulled it up on standby got fried.
Is the grey signal wire in the PSU supposed to be 0V when the PSU is on standby?
Yes I understand its a signal wire and not a power rail. And according to both EPS12v and ATX12v specs it's supposed to be off while on standby.