Dell Optiplex 7020 Power supply upgrade

Pls send pic and purchase link to your 24 to 8 pin adapter.  Do you have another desktop to verify the 700w psu works. I would stay away from Aresgame psu which is not a reputable name brand.

7020 mt stock psu is 290w.  When new psu+adapter doesn’t work, revert to old stock psu to verify pc still works.

PS Dell oem 365w psu 8+4 pin white + 6 pin black

https://www.ebay.com/itm/Genuine-Dell-365W-Switching-Power-Supply-HU365EM-00-7CR3P/125489453365?

@CBIVTI22 
The notes about the PSUs are really good information, thanks to you both. This has been an extreme budget build thus far, and I think I stupidly took the PSU for granted. The Thermaltake I thought I would be ok, I didn't know about this PSU cultist list site!!! Learned my lesson here. While I'm learning, are there certain things to look for to determine quality of a PSU? Brand name I get, I might try a Corsair next.

I'll use that site as a guide.

Thank you for the DELL PSU suggestion. Do you know if there is anything in for the Optiplex that goes to 500w for the mini tower?

This is the adapter we ended up choosing.
https://www.amazon.com/24-Pin-8-Pin-Supply-Adapter-Motherboards/dp/B08P3FX9YG/ref=sr_1_4?crid=12ZXLER0K2LGL&keywords=18+awg+atx+24+to+8+pin+mao&qid=1681079771&s=electronics&sprefix=18+awg+atx+24+to+8+pin+mao%2Celectronics%2C73&sr=1-4 

Fortunately, after we tried with the new PSUs we went back with the old one and verified everything is still working! Unfortunately, we don't have another way to test the PSUs. The self-test on the AresGame said good... but, I don't feel confident about it anyway re: brand. I don't think it has enough power on the 12v rails or something.

The Corsair CV 650/750 and CX-M are "C" Tier rated while the RM series are "A" tier (Excellent) rated. If you're doing an extreme budget build then "C" tier is fine. Higher tier units tend to be more expensive. I didn't know about the List either when I was building a gaming PC a couple years ago, and I had AresGame PSUs in all of them! I'm glad I found out about it before I had a chance to do any serious gaming on them.

Also, check this thread.  This may explain why the PSUs don't work, even with the adapter.  You'll need a high wattage PSU, not because of the total watts, but the combined wattage of the 3.3 and 5v rails.

Dell oem 290w and 365w psu were circa 2012.  The ATX12V 2.0 standard (The power on 3.3 V and 5 V rails was significantly reduced) was introduced in 2003.  It seems the Dell oem psu should have followed the the 2.0 standard.

Right now as of this typing, the models listed are out of stock. Anything you find will probably be scalper prices. The EVGA 700BR (C Tier), Thermaltake BM2 750, and the Corsair should be around $75. Been doing some research myself since I am also doing a budget gaming build, except with a 9020 MT, which is very similar to the 7020. (see this thread )

Ah so you're thinking it shouldn't need that much power? I'm looking at the back of the Dell 290W now and under output it has 
+12VA 14A MAX
+12VB 16A Max
+12VSB 1.667A Max
I don't even see information about the 3.3 and 5 V rails. Is it just not listed on that model?

Oh cool about the 9020! Do you think any C tier would be suitable or should I be looking at that 3.3v and 5v rail output still? Or as you mentioned would it just be suitable from that tier at a higher wattage like 700?

What GPU card are you powering?  That also makes a difference in PSU wattage.

For some reason, amps on the 3.3v/5v rails isn't listed for their 8-pin 290w PSU, as you noticed.  But is listed for their 275w PSU for the 9010.  So, as a general rule, you wouldn't want to go below 100w on those rails.  Besides, it's better to have more if powering a GPU card over 75w.  From the 9010 Tech Guide:

As you may have gathered from the speedstep posts from the thread that was linked a ways above, aftermarket PSU's may boast more total power, but may have less on the 3.3v/5v rails than a Dell OEM.  When an aftermarket PSU lacks power on those rails, it causes problems.

no worries of the 3.3+5v combined power for 7020/9020.  which video card are you upgrading to that makes you think you need a 500w psu?  I would google picture of other users 7020/9020 upgrade on internet for user psu validation.  You can get a new or used EVGA 500w pretty cheap.

EVGA 500w

I'm going to use a XFX RX 270, which is a bit hefty on power unfortunately. Getting a lower power GPU has definitely been in the talks. But, I got a really good deal on this one haha.
You know, I've been doing a lot of watching others upgrade this machine on YouTube, which led me to the Thermaltake smart White! That's even the PSU in that last picture if I'm not mistaken. So, it still eludes me why it didn't work with for me.

But, no sense crying over it. I think EVGA 500w or Corsair CX-M series 650W or ThermalTake BM2 SMART 750 are my contenders. I think the Corsair and EVGA were more popular amongst videos I saw.

Do you think that given the last picture with the ThermalTake Smart 700W (same one that failed for me) that the problem might be my adapter?
Thanks again!!

That's awesome about the rails information!!! Thank you! I'll hone in on a after-market PSU that has at least 100W on those rails. I've definitely been hearing that those rails are important, but I never had a concrete number to shoot for until now!
The GPU is an XFX RX 270 (pretty beefy in terms of power need), but the kicker: even without the GPU, the PC wouldn't turn on with those PSUs I tried.

Well, I have no clue as to why your Thermaltake PSU isn't working with the 7020.  You're certainly welcome to try a different adapter to rule it out.

A 500w PSU should be sufficient for 150w-180w card.  (I got two watt ratings off of Google.)  700w PSU will definitely leave you power to spare.  Not that it's the only good one, but EVGA BR PSU's always came recommended by speedstep, who was on this forum for many, many years.