Tomahawk B650 - Adding 2nd RAM chip issue

arcanebotanica

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HI Folks,

I custom built a PC with a Tomahawk B650 Motherboard.
It has all worked well this year.
However, I bought 2 x Kingston Fury 16MB DDR5 RAM chips.
The system boots with one chip installed; however, does not boot when I add the 2nd chip to the 3rd lane.
Does anyone know of any handy solutions?
Many thanks
Dan
 
1. Please clear CMOS by shorting the JBAT jumper for 5-10 seconds (with PSU powered off and power cord unplugged) (JBAT's location could be referred to attached screenshot)
2. Clean the memory module's golden finger with eraser and connect the memory module on different memory DIMM slots to check.
3. Could you provide full system configuration including the photo showing the memory sticker as the post advises: https://forum-en.msi.com/index.php?threads/posting-guide.38822/
Has the mainboard's BIOS updated to the latest 7D75v1R2 to check?
https://www.msi.com/Motherboard/MAG-B650-TOMAHAWK-WIFI/support
 

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Thanks Zerijelly,
I appreciate it!
Apologies but I am a bit of a rookie and I custom-built this back in January.
- I have cleared the CMOS yesterday - no change to the issue
- I alternate the 2 memory sticks and I get the same result. We tried multiple lane configurations back in January but I will try again.
- I have not checked the BIOS update - I will try this - thankyou!!
- System configuration - TOMAHAWK B650, AMD Ryzen 5 7600X 4.7GHZ, Kingston Fury Beast 32GB (2 x 16) PC5-48000 (6000 MHz). Is that enough?
- Photos of RAM attached. Thankyou
 

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Which memory slot do you install the 2 memory modules in?
It's recommended in user manual to install memories in the DIMMA2 and DIMMB2 slots, and they are the 2nd and 4th slots from the CPU socket.

I would disable XMP/EXPO when trying the first boot with 2 memory modules for better compatibilities and enable XMP after making sure two memories boot up fine.

1788747555330.png
 
Thanks Goodspeed- much appreciated!

Yes we install one chip in lane 2. It works fine. Then I install the 2nd chip in lane 4 and no go.
I have just updated the BIOS successfully and am going to now try again.
Then I will follow your advice for the setting suggestions.
I might then just try the RAM in all lanes and tick things off.
Really appreciate your help! :)
 
An update for you:
- I updated the BIOS as advised above.
- I tested both RAM chips in all lanes. Each chip - used singularly - only works in Lane B2. Lane A2 does not work.
HOWEVER, I have tried multiple configurations and I just tried Lane B2 and B1 and hooray!!! - it booted up.
I did get a warning that the RAM were not in the optimized lanes. I have ignored this for now and the computer has booted!!
The BIOS is showing both chips but the DRAM speed is 3600 MHz. I think it showed 4800 when one chip was in.
I have not altered the RAM settings and both XMP / EXPO are enabled at this stage.
Happy to hear from you if I should adjust anything manually - maybe just test it out for now?
As usual - completely in the dark as to why I got this result :),
Many thanks. Maybe the BIOS update did something. Appreciate!
 
- I tested both RAM chips in all lanes. Each chip - used singularly - only works in Lane B2. Lane A2 does not work.

I suggest to take off the cooler, take out the CPU, and inspect the socket for bent socket pins.

Whenever you have a slot (A2) or a whole channel (A1, A2) not working, but the modules themselves are ok, you should check the socket pins. A lot of the pins on the right side of the socket go to the RAM slots. If one or several pins are bent and don't make contact with the appropriate pads under the CPU anymore, then something like this can happen.

HOWEVER, I have tried multiple configurations and I just tried Lane B2 and B1 and hooray!!! - it booted up.

This is not a viable solution. If you only use one memory channel, then the RAM runs as single-channel, cutting the bandwidth in half. Also, you are stressing one memory channel fully and the other not at all. Then you can have things like the RAM going even below the safe JEDEC DDR5-4800 speed, like DDR5-3600. Which, coupled with it running in single-channel, means that it has the thruput of dual-channel DDR5-1800! Horrible performance.

You have to make it work in slots A2+B2. If you see that you have bent socket pins, you can try to repair them, in the thread I linked, I give some pointers.

The only weird thing about this all is that it supposedly worked fine before? You said you built this in January and it worked, but what was the RAM configuration then? It would be odd for a RAM slot to stop working suddenly, just because you changed the RAM. So I'm trying to understand what has ran from January.
 
Thanks Citay,

Much appreciated! Yes I am learning as I go along.

Re January: - no it has only worked with one RAM chip this entire time - and never two. It has only ever worked in lane B2.
I am only getting around to having a good go at it now.

Yes I have a son who is on the same page as you. Yes I have learnt now that this is a horrible solution and outcome. Thankyou
Yes he wants to take out the processor and inspect the pins and says the memory channel is likely dead.
That is our next step. Thanks for the guide links - really appreciate it!!
We will see how we go inspecting the processor.
Cheers
 
no it has only worked with one RAM chip this entire time - and never two. It has only ever worked in lane B2.

Adding the 2nd memory module (especially with DDR5) is gambling and asking for troubles.
If you need more memory you need to replace those 2 modules with a factory matched kit.
Also, a good idea is to use the known working module and test the A2 and B2 slots.
If one of them fails, yes, you need to reseat the CPU (and its cooler) and search for bent pin(s).
Also pay attention to the cooler mounting pressure as well.
good luck
 
Re January: - no it has only worked with one RAM chip this entire time - and never two. It has only ever worked in lane B2.

That was an immediate red flag. If you use a single module (which is perfectly ok for an office PC and any lighter use), it should always go into slot A2. When you find that it doesn't work in slot A2, but only in B2, then it's like I mentioned, it's quite likely that there are some bent socket pins. It can very easily happen with even just a slight mistake before or during CPU installation. So already in January, there was a clear hint that something isn't right, when the A2 slot was out of order. But at that time you didn't know about the connection between the socket pins and the slots, so it's understandable that it only crops up again now, when you want to use two modules.

I mean, theoretically it's also possible that the CPU itself has a problem where the memory channel A doesn't work. But what's much more common is that people discover some bent pins in the socket, due to a mishap when installing the CPU. A lot of people don't even realize at the time that they may have bent some pins with what they did, because it can happen very quickly and doesn't take much force. It is really an open-heart surgery moment of building a PC, before and during the installation of the CPU into the socket. And the repercussions of bent pins can be severe.

But let's see what you discover. If you can, take some photos of the socket, upload them to an image hoster like https://imgbb.com/ and link them here.
 
Thanks Citay,

Appreciate it immensely again! Cheers!
The only thing I passed to my son was the installation of the processor and the the heat-sink and fan. He is quite good with it - but even he knows that that is where the problem likely lies.

Good to know for next time. I had not built a PC for about 8 years. It was good to do it again.
My son will tackle it on the weekend. I am only doing light work-stuff for now so its running fine. Hopefully we fix it this weekend.
Ill upload a photo if I can.
Thanks again.
 
Hi Guys,
Just wanted to update you on the outcome.

Yes the processor was removed and damage can be observed to the pins on the motherboard-end / socket.
My son removed small shards of metal from in here and then we discussed possibly getting the motherboard fixed by someone.
He did look up the pin-specs and we had it up on a big screen and only one of these slots/pins seemed to be affecting memory. The others were non-allocated? pins/slots.
HOWEVER, he put everything back together and booted up the computer (after installing the latest BIOS update) - giving A2 and B2 a try with the the RAM - and it works!!!!! He couldn't believe it!!!!! I was laughing......
HOWEVER again, - he said to try something like Diablo2 Resurrected and see if it crashes or has issues. I am yet to do this.
You may advise that this outcome is still dodgy and I might be sitting on a time-bomb. I am investigating if someone can fix the motherboard for me. I would hate to just buy a new one.
Currently, both RAM chips work in A2 and B2. ????????
Thanks again (for now I am playing Dune2 in DosBox :) )
 
Yes the processor was removed and damage can be observed to the pins on the motherboard-end / socket.
My son removed small shards of metal from in here and then we discussed possibly getting the motherboard fixed by someone.

Ok. It can happen. The small shards of metal, well, I don't know what that could be other than pieces from broken-off pins. It would be very good to see photos of the damage, which you perhaps managed to take? I have seen hundreds of photos of sockets with bent pins in them and can give you an estimation about the severity of the damage. Some bent pins you can fix yourself.

HOWEVER, he put everything back together and booted up the computer (after installing the latest BIOS update) - giving A2 and B2 a try with the the RAM - and it works!!!!! He couldn't believe it!!!!! I was laughing......

That's not unheard of. When the pin was only bent ever so slightly that it didn't contact the pad under the CPU before, and gets another relief and then pressure again from the CPU re-seat, it can then be positioned to where it barely touches the contact pad again. If you read my Guide: Fixing bent pins in the CPU socket, at the very end of the guide, I show an example where the tip of a pin broke off, I bent the remaining stub at a higher angle, and this managed to get the RAM working again in the proper A2/B2 slots.

You may advise that this outcome is still dodgy and I might be sitting on a time-bomb. I am investigating if someone can fix the motherboard for me. I would hate to just buy a new one.

To say anything more concrete, I would have to see photos of the socket damage. It's good that it works with the RAM in the proper slots now, and usually, once the CPU is mounted in the socket, the affected pins won't suddenly get out of position again. The socket retention mechanism applies a considerable force onto the CPU, pressing it onto the pins, so it's not common for anything to change one day. It's much more common, as you observed, that it changes when you take off the CPU and then install it again, because any bent pins then have a chance to slightly move again, as they go through an unload-load cycle, so to speak.

So, there's two possibilities for you now: If you didn't take photos of the socket before, and want me or others to give an estimate about the situation, you would have to take off the CPU again and take those photos. But it's possible that the next time you install the CPU, the issue re-appears. Bent pins are unpredictable. So in that case, it might be better to attempt to fix the bent pins, the important ones at least.

Second possibility, you leave it like it is now. If it's really just the one pin that took out the A2 slot (not unusual BTW, one pin is always enough to cause a problem like this), then it's probably not gonna suddenly move under the CPU again one day. So if you're positive that the other bent pins are not important, and with the slot-A2-related pin obviously managing to get contact now, you could run it like this indefinitely. Don't buy a new board over one relevant bent pin.
 
Thanks Citay,
I left it with my son and he did not take photos of the broken pins unfortunately.
However, it is all still working and so I am grateful and it continued to work under a heavier load as well.
So I will see how it goes long term.
Appreciate the advice immensely and great to learn so much from the experience!
 
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