Dell Optiplex 7020/9020 using OpenCore + Intel HD4600 or AMD graphics

[trs96]

Reinstallled Win10. Using the original RAM, the two slots near the processor still appear not to work. I googled and this seem an often found error on 9010. I tried cleaning up the original RAM, same (it only works with the two slots near the Hard Drive caddy)

You said previously that you got the 3,3 error code which means the OS couldn't detect the ram in the slot(s).

There is most likely a problem with two of your motherboard's ram slots not functioning normally. That's what seems to me to be the problem. The ram may be OK. Post some pictures of which slots you have the ram in when it doesn't work and when it does.

If the seller only tested two DIMMs of ram in the two working slots, they may never have known about the problem with the other two slots. I would try just one stick of ram at a time in each slot and see whether the OS picks up each slot as functioning. If the slots don't all work it will require an RMA from the seller to get a board with all slots working. Clearly document your findings for them.

 

[trs96]

Here's why having only two slots working (right next to each other) is no good. You can't run the ram in dual channel mode. It has nothing to do with which BIOS version is installed. It's most likely that two of the slots are faulty. Your two DIMMs of ram must be in either slots 1 and 2 or 3 and 4 (color matched slots) to work in dual channel mode.

Here's how macOS Monterey reports the order of my ram slots.

 

[Popwell]

Thanks, yes I tested all four memory modules in the slots that work, ran diagnostic on them and the ram is all fine.
The four sticks work in the other slots 4 & 2, just not in dimm 3 and 1.
I contacted the seller, he'll probably have to replace the computer, lucky me he has tons of them in stock.

 

[trs96]

I contacted the seller, he'll probably have to replace the computer, lucky me he has tons of them in stock.

If he claims to be a Pro refurbisher, he's not doing adequate hardware testing to be calling himself that.

 

[Popwell]

I don't think many of them do, especially if they have tons of units for sale. They let us do the ground work, it saves them time LOL.

 

[trs96]

They let us do the ground work, it saves them time.

It does cost you your valuable time though. You now have to pack it up, ship it back and wait for the next one to arrive. If that one has any issues, ask for a full refund and find another seller.

 

[Popwell]

He's not too far, so I might just pop in, will see. The RAM as acted funky again, so I put the original RAM back in, and will bring the full set back to the store for a refund. I'm guessing it has to happen with second hand stuff.
I googled the problem, and it seems very common even for brand new Dell computer buys.
Maybe the right ram would solve it. I don't think it's the CPU badly placed, as it has dents so there's really only one way to put in place.

 

[Popwell]

So I checked out and really the seller sent me his best unit. He has other, but they are older built (you can tell from the Windows sticker outside of the box) and battered. However I spent more time online searching, and here's might be the solution you suggested there:

Why not do this from the start ? A 2 x 8GB kit leaves room for an upgrade to 24 or 32GB later on and should cost less than two 2 x 4GB kits. I would advise anyone upgrading the ram with a new kit to go the 2 x 8GB route. One of those kits should run in dual channel mode.

On a Dell forum, a guy said he had the same problem as me, until he fully slotted 4 x 8gb RAM sticks in. As the build is Core i7, it might be that Dell prevent dual Memory if there is not enough RAM in each slot (ie 4 in one, and 4 in the other one) to optimize the CPU performance.

After drawing up the memory configuration schematic from Dell, I found that my 7820 tower needs another 16GB ram to boot properly, because it is running dual CPU's. After my 'duh' moment, I ordered a duplicate set of RAM, I installed all 4 sticks and boom, my PC was properly able to boot.

So I'm returning my RAM, and will order a full set of 4x8gb from Amazon. We'll see how it goes, but my feeling is that this will work. Maybe!

 

[trs96]

So I'm returning my RAM, and will order a full set of 4x8gb from Amazon.

I'm interested to see if this theory works out. I've never personally experienced this problem with any Dell desktop. I've been purchasing them for the past 20+ years and have lost track of how many over that time period. I've seen PC desktop motherboards with failed slots but all the pre-builts I've bought haven't had any faulty ram slots. Getting a defective stick of ram is much more common.

 

[trs96]

For anyone else following this thread, the problems with non-functioning ram slots that @Popwell is having can most likely be avoided. Buy from a Professional Refurbisher (at least a MAR) that has a large inventory of 7020/9020 Optiplex models and that fully tests functionality before shipping. This is why I've provided links (to Amazon/Newegg) and suggested sellers with good seller ratings. You can find the links in post #3 of this thread.

Dell Optiplex 7020/9020 using OpenCore + Intel HD4600 or AMD graphics

Dell Optiplex 7020/9020 OpenCore Guide The original Dell OptiMac Golden Build guide was posted 3 years ago in May 2019. Mojave was the latest macOS version then. I didn't think we would have Monterey support in 2022 but we've found that these models are still fully supported, hence this updated...

www.tonymacx86.com

Many large sellers on Ebay will only test that the PC boots to BIOS and that's it. They do the bare minimum and usually don't include a HDD with Windows installed either. They sell refurbs with more cosmetic imperfections (dents, dings, scratches) that the larger refurbishers were not willing to sell. You'll find a lower price for these, mostly because they're not paying techs to do any testing or cleanup of the PC. You can buy these to save $ but it will cost you more of your time cleaning it and resolving potential hardware problems. You can find a few good refurbs from reputable sellers on Ebay but most of them are not worth buying imo.

I can't guarantee that you will get one that is perfect if you buy from Amazon or Newegg. You can always return it for a refund/replacement within the alotted time the seller provides for returns. It's also why I suggest using the Windows install to fully test all the hardware as soon as you get it. Along with replacing the CMOS battery (if weak) and the IHS thermal paste. Most refurbishers do not do those two things. It takes more time and money to pay techs to do so. You can save a lot of money with these older PCs but it requires that you test the hardware yourself when receiving the PC.