[SOLVED] MSI B450 tomahawk and 2400G Ryzen - wont post

Roger Bruce

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Oct 2, 2013
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Brand new Ryzen 2400G and MSI Tomahawk B450 Mobo, with 16G DDR4-3200 RAM and cryorig H7 cooler.

CPU is installed correctly... RAM in A2 and B2 Dimms….650W Thermaltake Powersupply (way OTT). On power up, we get 3 solid EZ-debug LEDs.... CPU, DRAM (Flickering), GPU. No front panel switches or buttons are functioning (power, reset etc), and no post or video signal at all. Tried HDMI and DVI connectors on the Mobo ports...nada. Did a bios reset, still the same.
 
Solution


That's actually a darn good idea...you can pull out everything...no cpu, memory nor gpu. Disconnect everything, front panel, drives, audio cables, USB ports, CPU power. All you need is the 24pin power connector connected to the board. Just plug in the USB stick with latest BIOS and press button...if THAT doesn't work then you know it's the mobo or powersupply.
The usual answers: double/triple check electrical connections, that CPU cooler is properly seated on CPU, try one stick of RAM at a time. If everything is confirmed properly connected you may need to remove the board and power supply from case and 'bench test' it as it could be shorting inside the case.
 

Roger Bruce

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Oct 2, 2013
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yup..did that...I am in the fortunate position of having another B450 and Ryzen 2400G sitting here in sealed boxes so will do a process of elimination and let yall know..I fear a dead mobo or APU (most likely the tomahawk tho)
 

shknawe

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Oct 22, 2016
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Did you try updating to the latest bios, you can do that with a thumb usb without cpu active on that motherboard?
 


That's actually a darn good idea...you can pull out everything...no cpu, memory nor gpu. Disconnect everything, front panel, drives, audio cables, USB ports, CPU power. All you need is the 24pin power connector connected to the board. Just plug in the USB stick with latest BIOS and press button...if THAT doesn't work then you know it's the mobo or powersupply.
 
Solution

Roger Bruce

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Oct 2, 2013
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ok..I built this on the bench...then slowly subbed out parts....for the same result across 2 diff mobos, CPUs and DRAM....last thing left before a bios patch, is the power supply....which is of "unknown origins"...so switching out that 600 Thermal take for a 850 gold rated one
 

Roger Bruce

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Oct 2, 2013
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Success!. while I was throwing (almost literally) stuff back into the shelving..what do I spy in the back....oh, a corsair power supply box....with...8-8 Mobo power plug in it..minor victory.....plug it into the 850w PS....post!...major arm pumping and cheering...all on the original parts.
 

shknawe

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Oct 22, 2016
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GOOD FOR YOU!:bounce: Nothing more frustrating on a new build that goes waa waa waa on power up!:fou:
 

Roger Bruce

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Oct 2, 2013
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there are a few undocumented tricks with the B450 Tomahawk Mobo. Firstly, without turning on A-XMP, memory speed will default to 2133. by default it is disabled. Enabling it is a bit confusing because you can do it from the front panel of the BIOS by selecting "1" or "2" in the XMP button window. these are profiles that pertain to the DIMM pairs, so if only running 2 DRAM chips, make sure you enable "2" (A2 and B2 are the primary).

Also, the Ryzen 2400G...or the other Ryzen 3 vega APU, you need to go into the advanced bios features..integrated graphics..turn the second option to "Forced"...this will unghost the third option, which is the RAM memory allocated to the vega chipsets, and let you increase it from the default 512M up to 2G....SIGNIFICANT performance kick, doing those 2 things...and neither of them are documented in the manual.