VRM modify ICC_MAX to run high TDC OEM cpu

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Zhengrankela

Member
Oct 12, 2024
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Okay, let me make another correction. The VRM pin for H3C C35 platform is J266
Among them, 1 scl, 2 gnd, and 3 sda
Because its PMBUS output is hung on the bridge, the multimeter cannot detect it.
 

WANGXIANG

New Member
Feb 27, 2025
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I also ran the command MCP2221a_iccmax_FF.exe -scan 20 70, but no devices were detected within the specified I²C address range.
 

pvd276

New Member
Apr 15, 2025
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i scan mainboard foxconn RM760-FX , not show icc_max, only show


scanning at addr: 60
probably TPS53679 found at addr: 60
scanning at addr: 61
probably TPS53679 found at addr: 61
scanning at addr: 62
scanning at addr: 63
 

ericzqu

New Member
Apr 24, 2025
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Just got a Cisco C240 M5, and I found the vrm chip (PXE1610CDN) which is close to a 4 pin header. I cannot read found the trace of the board on what’s leading to the pin. Is there a way to identify them without using fancy equipment? Any help is much appreciated!
 

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RolloZ170

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Apr 24, 2016
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Just got a Cisco C240 M5, and I found the vrm chip (PXE1610CDN) which is close to a 4 pin header.
header must not have connection even if close to the VRM controller.
Is there a way to identify them without using fancy equipment?
look at the circuit diagram from manufacturer, if you don't have it no.
what helps is: multimeter, magnifying glass or head magnifier.
note: there can be a 20-33ohm series resistor in SDA/SCL signal.
edit:
check if GND is connected to Ground (e.g. any shield)
IMG_5272sth.jpg
1610 pinoutsth.jpg
update:
pinout is correct for Cisco C240 M5
The addresses are 70 and 72
 
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savio

New Member
May 21, 2025
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you have to write your own software.
i do support ElmorLabs EVC (XML script) and MCP2221a ( with my c# CLI )
new: CLI for EVKT-USBI2C-02 beta stage.

you have X11DPi-N revision 2.0 or higher ?
if not e.g. rev 1.21 don't work.
@RolloZ170 Thanks for the good work. I have a X11DPi-NT Rev: 1.21. Is it impossible to perform this mod?
I saw the following 3 commands and I am not sure which one applies to me:
  • MCP2221a_iccmax_FF.exe -MP2955A 20 REM X11SPM/X11DPi first
  • MCP2221a_iccmax_FF.exe -MP2955A 21 REM X11DPi second
  • MCP2221a_iccmax_FF.exe -MP2955A 20 21 REM X11DPi first second

Thanks!
 

RolloZ170

Well-Known Member
Apr 24, 2016
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I have a X11DPi-NT Rev: 1.21. Is it impossible to perform this mod?
I saw the following 3 commands and I am not sure which one applies to me:
1.21: this is the rev. with the VRM design bug, if blowed up, SM will replace it even after warranty period.
rev. 1.21 uses still TPS53679 (TI) controller not MP2955A (MPS)
do a
MCP2221a_iccmax_FF.exe -scan 10 7F
BUT I DON'T RECOMMEND TO USE HIGH TDC PROCESSORS ON THIS REVISION.
( bec. it can blow up even with the std. SKUs )
IMG-20191212-WA0007vrm70.jpg
 
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savio

New Member
May 21, 2025
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1.21: this is the rev. with the VRM design bug, if blowed up, SM will replace it even after warranty period.
rev. 1.21 uses still TPS53679 (TI) controller not MP2955A (MPS)
do a
MCP2221a_iccmax_FF.exe -scan 10 7F
BUT I DON'T RECOMMEND TO USE HIGH TDC PROCESSORS ON THIS REVISION.
( bec. it can blow up even with the std. SKUs )
Thanks for the info. What does the -scan option do? Does it read the addresses? If I really do perform the mod, do I need to run: MCP2221a_iccmax_FF.exe -TPS53679

When you say even standard SKUs can blow up the VRM for the 1.21 rev board, does it mean even if I stay within 205W TDP (but very close to the limit) as per specs, I risk blowing it too? Asking this as I was previously considering 8259CL for cheap because it is close enough to the 205W limit, but knowing this I might consider sticking with much lower TDP CPUs.

Can I mount an additional heat sink on the VRM for CPU1 on my board to minimize that issue?

For BIOS, am I correct in assuming that it does not matter what version I have when running this mod as long as it is one that supports my CPU?

Thank you for your response!
 
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RolloZ170

Well-Known Member
Apr 24, 2016
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Thanks for the info. What does the -scan option do?
-scan 10 7F
scans from address 10 to 7F for vrm controllers. you need the address to programm the right ones.
e.g. if two TPS53679 are found note the addresses. if for example the 2 addresse are 20 and 21 you use this:
MCP2221a_iccmax_FF.exe -TPS53679 20 21
When you say even standard SKUs can blow up the VRM for the 1.21 rev board, does it mean even if I stay within 205W TDP (but very close to the limit) as per specs, I risk blowing it too?
sure. this rev. has a VRM design BUG
Can I mount an additional heat sink on the VRM for CPU1 on my board to minimize that issue?
not a bad idea.
from rev. 2.0 and up the VRM controller was changed and Heatsink holes for CPU1 VRM powerstages added,
required if NOT used in a server chassis with jet engine FANs.
but even in an server chassis the VRM BUG results i a blown VRM power stage.
IMG-20191212-WA0007vrm70.jpg
For BIOS, am I correct in assuming that it does not matter what version I have when running this mod as long as it is one that supports my CPU?
correct. there is no TDP block in the BIOS.