Truenas sb405-vl keeps rebooting

TrueNAS General
1

We have truenas and moved it and now when powering on keeps rebooting during post check:

Post code 76

Post code ee

Post code e5

Post code 83

Then reboots

2

Sounds like a hardware problem, but you’ve given us nothing else to work with. Check the motherboard’s manual for meanings of the POST codes.

3

Hi,

Thanks I checked and it shows these:

0x83 set cache for physical memory

any idea what fix would this be?

I have reseated all the memory slots and even tried booting truenas with just one dim.

4

Try running memtest from a boot cd / USB. Run overnight as a minimum, preferably 24-48 hours with multiple passes

5

Sounds like a question for whoever made or sold you this system, or failing that, your favorite LLM. Really, if the system’s failing to POST, the issue can’t possibly have anything to do with TrueNAS.

Perplexity answer

A SB405-VL system constantly reboots during POST. The last POST code shown on the display is 0x83, which according to its manual means “set cache for physical memory.” What would be likely causes and remedies?

It is most likely hanging in the memory‑initialization path (CPU cache + RAM) and rebooting when that step fails; typical causes are bad or marginal RAM, incorrect population, wrong/unstable CPU or memory settings, or a failing motherboard.

What POST code 0x83 implies

On this AIC SB405‑VL, POST 0x83 is documented as “Set cache for physical memory,” which is part of the memory‑initialization and cache‑enable sequence very early in POST. A reboot at this point usually means the BIOS cannot reliably bring up CPU cache and main memory, so it will reset and try again.[1]

Likely causes

Most common hardware causes in this phase:

  • Faulty or marginal DIMM(s) (bad chips, ESD damage, aging, etc.) so that enabling cache over them causes parity/ECC or timing faults.
  • Incompatible DIMMs for the platform (wrong type, speed, rank, voltage, or not on the board’s supported list).[2][1:1]
  • Incorrect memory population (wrong slots first, mixed modules that violate population rules, or uneven ranks/channels).[2:1]
  • Over‑aggressive timings or speed from prior BIOS settings (XMP/overclock, manual timings) that the board is still trying to use.
  • Failing CPU (integrated memory controller / cache) or bent pins in the socket.
  • Failing motherboard traces, memory power rails, or VRM instability that only shows when cache + DRAM get enabled.
  • Corrupted BIOS configuration (bad CMOS settings) or a marginal CMOS battery causing unstable configuration at power‑on.[3]

Practical remedies and tests

Work methodically and change only one thing at a time:

  1. Clear CMOS completely
    • Power off, remove AC, move the CMOS‑clear jumper or remove the battery for a minute, then restore and boot.
    • This forces safe memory timings and defaults, removing any bad overclock or timing settings that might cause the 0x83 loop.[3:1]
  2. Test with minimum memory
    • Install only one known‑good, supported DIMM in the first required slot (per the memory‑population rules in the SB405‑VL manual).[1:2][2:2]
    • Try each stick individually and each slot individually to see if the board only fails with certain DIMMs or sockets.
  3. Verify DIMM type and specs
    • Confirm the exact memory type, voltage, and speed are supported by this platform (e.g., specific DDR generation and registered vs unbuffered).[2:3]
    • Remove any mixed‑type configuration (different sizes, speeds, ranks) and test with a fully homogeneous set.
  4. Inspect physical hardware
    • Check for bent pins or contamination in DIMM slots and the CPU socket, and reseat both RAM and CPU.
    • Look for bulging capacitors, burn marks, or corrosion around the memory VRM and CPU power areas.
  5. Try different PSU and power rails
    • If possible, test with a known‑good power supply; marginal 12 V or 5 V can cause failures when CPU cache and memory current draw spikes.
  6. BIOS recovery/update (if available)
    • If the board supports a recovery device (note that 0x84 is “Recovery device initial” in the same code list), reflash or recover the BIOS to a known‑good revision using the vendor’s documented procedure.[1:3]
    • Only attempt this after confirming basic power and memory are OK, since a failed flash would brick the board.
  7. Isolate to CPU vs board
    • If you have access to another compatible CPU, swap CPUs with the same RAM set.
    • If the POST behavior follows the CPU, the CPU (or its cache/IMC) is suspect; if it stays with the board, the motherboard is more likely the issue.

If you tell me whether you’ve already tried different DIMMs and a CMOS clear on this board, I can suggest a narrower next step (for example, whether to focus on the CPU socket or on BIOS recovery).
[4][5][6][7][8][9][10][11][12][13][14][15]

⁂

If this problem began just after moving the system, does that narrow down or alter likelihood of the possible causes?

Yes. If it started immediately after a move, physical / mechanical issues jump much higher on the list, and “silent” component failures (like suddenly‑bad RAM ICs) become less likely.[16][17]

Causes that become more likely

  • Partially unseated DIMMs or CPU from vibration or case flex; even a tiny change in contact pressure can cause failures exactly at memory/cache init.[18][17:1]
  • Cracked solder joints or flex damage on the motherboard, especially near DIMM slots, VRMs, or heavy heatsinks, from being carried or bumped.
  • Loose power connectors (24‑pin, EPS CPU power, or modular PSU cables) that sagged or twisted in transit and now droop just enough to mis‑contact under load.[16:1]
  • Case‑related shorts from a shifted standoff, screw, or cable now pressing under the board or against exposed pads; that can cause very reproducible reboots at the same POST stage.[19][20]
  • Heatsink/cooler weight stressing the socket area, changing contact quality for CPU and memory traces when the chassis was moved or set down hard.[20:1][17:2]

Causes that become less likely

  • Slow, time‑based failures like aging capacitors, gradual RAM degradation, or firmware corruption are still possible, but less favored when the failure correlates tightly with a one‑time event (the move).[21][22]
  • Unchanged BIOS settings (timings, overclocks) are “background” risk but do not explain why it worked before and not right after transport unless combined with marginal hardware that the move pushed over the edge.

What I’d prioritize now

In this scenario, I would focus on:

  1. Fully reseating:
    • All DIMMs (remove, inspect contacts, reinstall with firm, even pressure).
    • CPU heatsink and CPU (if you’re comfortable pulling it), check for socket/pin issues or board warping near the socket.[17:3][18:1]
  2. Reseating and visually confirming:
    • 24‑pin ATX, CPU power, and any backplane/power daughtercard connectors.
    • Any add‑in cards that might slightly lift a corner of the board.
  3. Checking for shorts:
    • Ensure every motherboard standoff lines up with a mounting hole and there are no “extra” standoffs under the board.
    • Look for a rogue screw, cable tie, or metal edge touching solder pads near DIMM slots or the back of the CPU area.[19:1][20:2]

If you can test the board outside the chassis on an insulated surface with only CPU, one DIMM, and PSU connected (no drives, no add‑in cards), that’s often the fastest way to prove or rule out a case‑related short.

Have you already tried a full reseat of RAM, CPU, and all power connectors since the move, or has it only had basic “push on the modules” checks so far?
[23][24][25][26][27][28][29][30]

⁂

If the system won’t POST, it seems unlikely we’d be able to get to this point.

  1. https://www.aicipc.com/image/images/psg/SB405-VL_v1_6_101624.pdf?t=20250327105117 ↩︎ ↩︎ ↩︎ ↩︎

  2. https://www.aicipc.com/image/images/psg/SB405-VL_Datasheet.pdf ↩︎ ↩︎ ↩︎ ↩︎

  3. Troubleshooting POST numeric error codes ↩︎ ↩︎

  4. POST Codes ↩︎

  5. List of Dr Debug BIOS Codes - Motherboards - Level1Techs Forums ↩︎

  6. https://linustechtips.com/topic/95872-a-couple-issues-memory-cant-be-read-how-to-recover-ami-bios/ ↩︎

  7. POST Beep Codes ↩︎

  8. https://bitsavers.org/pdf/americanMegatrends/Programmers_Guide_to_the_AMIBIOS_1993.pdf ↩︎

  9. Troubleshooting POST error codes ↩︎

  10. https://manualzz.com/doc/68523301/aic-sb403-vg-user-s-manual ↩︎

  11. https://manualzz.com/doc/74100617/aic-tb116-dl-user-s-manual ↩︎

  12. Super Socket 7 Motherboard Manual | PDF | Bios | Hard Disk Drive ↩︎

  13. https://www.supermicro.com/manuals/other/AMI_BIOS_POST_Codes_for_Grantley_Motherboards.pdf ↩︎

  14. https://asrock.com/support/index.asp?cat=Debug ↩︎

  15. AMIBIOS beep and POST codes list – Blog – The Retro Web ↩︎

  16. Reddit - The heart of the internet ↩︎ ↩︎

  17. [SOLVED] - Bootlooping after moving | Tom's Hardware Forum ↩︎ ↩︎ ↩︎ ↩︎

  18. Reddit - The heart of the internet ↩︎ ↩︎

  19. Reddit - The heart of the internet ↩︎ ↩︎

  20. https://www.youtube.com/watch?v=jVRJGtMgjTg ↩︎ ↩︎ ↩︎

  21. Solved: HP ProLiant DL380 Gen9 got stuck in "Early system ... - Hewlett Packard Enterprise Community ↩︎

  22. https://www.youtube.com/watch?v=y9umSeQCFkw ↩︎

  23. https://www.facebook.com/groups/372119787729533/posts/1201039214837582/ ↩︎

  24. https://www.youtube.com/watch?v=vWjMt8GMsX8 ↩︎

  25. https://linustechtips.com/topic/1197549-pc-constantly-stuck-in-bootpost-loop/ ↩︎

  26. https://support.hpe.com/hpesc/public/docDisplay?docId=ilogen11-msg-en_us\&page=class0x0032code0x0232-gen11.html\&docLocale=en_US ↩︎

  27. https://www.aicipc.com/image/images/_index/2024%20AIC%20Catalog.pdf ↩︎

  28. https://www.youtube.com/watch?v=DaLziCzyvK4 ↩︎

  29. https://www.aicipc.com/image/images/psg/SB405-VL_v1_6_101624.pdf?t=20250327105117 ↩︎

  30. Large Pool preventing reboot | TrueNAS Community ↩︎