Today, from instructions in Speedpatch thread, I set my overclock profile to:

use the ideal profile but change the upthreshold to 95
and change the samplerate to 300000
enable vdd1 and vdd2 (change to 1)
set powersave_bias to 20
and change maxfreq to 805
and change ignore_nice_load to 0

now my telephony functions are BROKEN. phone still asks for SIM pin, which I put in correctly (tried 2 SIMs). but after booting there is no reception icon, and cannot send sms/make calls. Upon booting I do NOT get "all telephoney functions disabled" message.

If i boot with no SIM, the icon for no SIM shows. Tried reverting back to old settings, re-installing kernel 48. no go. now im trying to reflash but my laptop wont recognise my device.! have flashed my n900 1000's of times in the past, but havent for ages (thanks to backupmenu!). since then I have this new computer that has windows 7.. I hope someone can help! thanks!!

edit: I plug my n900 into my PC and it says "installing drivers" it gets to last step then says "device unplugged". which it is not. tried multiple times in all direct USB ports. same after pc reboot also.

I suggest you try with a linux image. Ubuntu Live CD should work too if you don't want to install. Download the 32-bit version. Aftyer that get flasher for linux

After installing it first run the message in the terminal without the -R part before connecting the device. Safer this way (ie: sudo flasher-3.5 -F <firmware-image> -f).

After running the command connect your N900 while pressing the u key. Keep pressing the U key for at least a minute. If the PC still doesn't start flashing it, release the U key. Try with different USB ports and if possible not a hub.

I guess try a different sim card first to confirm. It might just be your sim card pin is not correctly sit.

Have you ever disassembled your N900? I did mine countless time.
Remove Kernel Power and revert it back to stock, you should be fine after that. Otherwise it could be that your device OS is corrupted. Reflash will fix this.

There is nothing needed to be done with your new computer. Just download flash maemo, then download the image file. Run the commandline and put the device into flashing mode then you're done.

I already said I tried 2 SIMs and put code in correctly.

Fixed my problem with flashing, I have Win7 64bit, I had to do a little workaround to get maemo flasher to see my device.

http://wiki.maemo.org/Updating_the_t..._Windows_7_x64

reflashed and still no telephony!

does flashing revert to stock kernel? Im pretty sure it doesnt. whats the easiest way to do this? thanks

The rootfs, when flashed with the flags from the reflash wiki page, erases and rewrites the CMT (phone), x-loader, kernel and rootfs areas.

If you flashed rootfs, and the phone still doesn't work, do a emmc+root reflash. Failing that, take it to Nokia Care, or try the pin-bending stuff that people have been posting on TMO.

I always flash root & emmc, and bent my SIM pins earlier..

phone reads sim IMEI and lock code, but gets no signal.. tried 2 different carriers SIMS

If those two SIM cards works with other phones just not with N900, I'd check dmesg and maybe even lsmod from N900. This is a far shot (I know because I have two N900, one with SIM card and is connected to the cellular network and the other one doesn't have SIM card and has no cellular connectivity), but it may show information as to why it is not connected to the cellular network.

Here is my pastebin output of one N900 connected to a cellular network and the other not connected at all. The first column is for N900 connected to a cellular network and the second column is for N900 not connected to any cellular network: http://pastebin.com/3r94eKp7 . Judging from the output, the missing modules seems to note that there's no significant difference (i.e. that one has cellular module loaded and the other one doesn't) between the two. I'm presuming the module that deals with connecting to cellular network is loaded regardless whether or not you have a SIM card inserted into the N900?