Hello, everybody. First of all, I want to clarify that I am completely unfamiliar with BIOS modifications and updating unless according to official procedure, so don't wonder if you find my questions strange and please, describe in details your answers. I have Lenovo ThinkPad R61 15" 4:3, motherboard FRU 42W7822. Some of you may know that for T61\R61\X61 ThinkPads there are modified BIOSes [ forum.notebookreview.com/lenovo/459591-t61-x61-sata-ii-1-5-gb-s-cap-willing-pay-solution-8.html#post6501443 ], based on the latest Lenovo BIOSes, that enable SATA 3.0Gb/s speed and few other things (the officials Lenovo's are limiting the speed to SATA 1.5Gb/s). These modified BIOSes also allows using Penryn CPUs with 800Mhz bus (45nm) on motherboards which are designed for Memron CPUs with 800Mhz (but 65nm), bypassing thermal sensing errors which enevedably occurs with the newer Penryn CPUs. I have updated my BIOS with the modified one and installed T9500 CPU, but the system is not able to start - if I push the button, the fan starts for a while, then stops and there is only a black screen. If you look at the link, under Thermal sensing colum for R61 standart screen there is n/a, which I don't know what exactly means, but I think that my problem is missing ID codes for these CPUs because: 1- looking at Lenovo R60/R61 standart screen Hardware maintenance manual [ support.lenovo.com/us/en/docs/MIGR-64200 ], Penryn CPUs are not available for this model, but they are available for the widescreens R61s. 2- No one with that same motherboard as mine was able to run any Penryn CPU, so the problem is not in my CPU - it runs fine on ThinkPad T61. Basically, these 4:3 models aren't widespread, so there isn't much info about other models motherboards being able or not able to run Penryn CPU, but I suppose that the problem is nor the motherboard itself. Other user was able to load BIOS ver. 2.24 for widescreen R61 on the same model motherboard and successfully run T8100 - look at this post: forum.thinkpads.com/viewtopic.php?f=29&t=101626&p=745097#p731381 3- if you install Penryn CPU without modified BIOS in Memron board, you will pass POST, but every time the system starts, you will see thermal sensing error message. So my black screen is another story. That's why I think that it's missing codes for these processors, or maybe something related with the EC and I want to compare a widescreen and standard BIOS to see the differences and wether if it is missing something. Do you think that I am right in my thoughts, or it could be something else missing in that BIOS? There is some info on the web - some old, some things for UEFI Phoenix BIOSes, adding SLIC tables, tutorials for certain modifications, but nothing about adding CPUID microcodes and I need really a good guide for begginers - starting with under what OS, which programs to use to decompile and compile the BIOS, some guide how to easily find/compare certain sections or tools if available, manuals and so on. Also, is any of you familiar with old ThinkPads' BIOS recovery procedure in case that I mess something, or it will be imposibe to do anything?