CPU Upgrade Failed (mostly): TK-42 in LT3103u

Hi,

Firstly, I have to send out a huge thanks to the community for all of the information already posted regarding the LT31x series of netbooks. This forum has been invaluable to me in this respect. From the dis assembly guide to the CPU voltages, this is excellent information. It is, in fact, where I got the notion to upgrade to the TK-42 in the first place. But more on that....

I've read on here several people who successfully swapped out the stock L110 for a TK-42 and, to my knowledge, no one has had one fail...until now. I was fortunate enough to get my hands on one, but, of course, it doesn't work...well, sort of. This is what I have so far:


- The system will POST (almost) every time. I can access the BIOS settings and the F12 boot menu. The CPU shows up clearly as an AMD TK-42 Turion X2 1600 Mhz. This is the only thing the PC will do consistently.

- I can get the PC to boot into Windows SOMETIMES (rarely. I'm running Windows 7 Pro x64). I cannot for the life of me figure out what in the hell is allowing it to boot sometimes and not others. I about pulled my hair out disconnecting internal cables, reseating cables, swapping out RAM, wifi cards, et al to figure out why it would boot sometimes and not the others. I cannot discover any clear pattern whatsoever. At this point, to get the system to boot, it really is a game of dice. I have to boot it, wait for it to hang, reboot, repeat, until it will eventually get all the way through the boot process. It's worth pointing out that in order for me to boot into Windows, I have to be using the AC cable only. I cannot use the battery only, nor can I use the battery+AC.

-It will not consistently boot with the HD removed and booting from a flash drive. The best I can muster is a very bare-bones rescue system that runs a meager X11 session, and it will only work half the time. Ubuntu just won't do it. Still on AC only.


A little more information about the crashes:

-The PC stays on, but HD activity is immediately halted and the screen goes black. It requires a hard reboot (no CTL+ALT+DEL regardless of what stage in the boot sequence the crash occurred).

-If I boot into Windows Safe Mode, the crash ALWAYS happens when loading 'CLASSPNP.sys' .

-Windows Startup Repair crashes whenever it tries to go into graphical mode.

-Ubuntu fails whenever it tires to go into graphical mode.

-MEMTEST86+ WILL NOT COMPLETE. It crashes at ~64% done. Windows Memory Diagnostic will do the same, though it doesn't usually make it past 11%


The thing that really pisses me off is that if by chance I get into Windows and run RMClock to decrease the voltages and underclock, the thing works. I can leave it on for a few hours, put it to sleep and resume OK, whatever. But even still it seems it will eventually crash again. The temp never gets about 55 C while running RMClock, so I do not see how this could be an overheating issue (used AS5 for the thermal paste), but I could definitely be wrong.

I know Turmlos was able to get this guy running OK @ 1.4 Ghz, not sure why I can't run it.

If I replace the CPU back with a TF-20 or the L110, I experience 0 problems. So any idea what could be causing this? I don't think it's an OS issue if it won't even run with HD removed and booting a rescue OS from a flash drive. The only things I can think of would be:

a) CPU is pulling too much power is my best guess, based on the AC cable part.
b) CPU is somehow slightly messed up
c) RAM isn't quite right, though I've tried two different PC-5200 sticks with the same results


Any suggestions would be greatly appreciated. Thanks greatly in advance.


Regards,

Steve

 

if the CPU is running 1.6 GHz this also will increase the memory speed. 1.2 GHz runs it lower. if the proper sped is not being selected at boot this can be an issue as it will essentially overclock the RAM.

If you can get to it what does cpu-z report the memory running at? Also what does HWmonitor show for temps too, just to be safe there.....

 

Idle temps in HWMonitor are around 45 for core 0, 30 for core 1. Under HD video load they'll shoot up to 57 and 39 respectively (this is underclocked and undervolted via RMCLock; the full 1.6 doesn't last very long).

I hadn't really thought about it since the TF-20 is a 1.6 ghz proc, but you're right, it does boot at 1.2 for some reason. I went out and got some PC-6400 to test. It didn't seem to quite fix the problem. Didn't boot up all the way the first time (died at the login prompt), but it did on the second try. Not sure if has helped or not yet, I'll see if she'll stay on longer this time.

As far as the memory goes, I'm currently running 6-6-6-18 @ an average of 200 mhz due to the 4x RM underclocking. Thanks for the quick reply!


Edit: I also forgot to mention I'm running BIOS v 1.3302. I haven't had the nerve to try the modded BIOS yet.

 

Alright, turns out the RAM didn't quite fix it. A this point, I'm about 80% positive this is an electrical problem and the CPU is simply consuming too much power.

But for that other 20%, does anyone have any suggestions? I think I'm going to try to overwrite the DSDT table in the BIOS somehow to make it boot at a lower voltage/clock speed and see if that will help. I say 'somehow' because I don't really know how to do this, but I've seen some posts on it around here so I'll give it a shot. If anyone has some more insight into this I'd be appreciative.

Regards,
Steve

 

Ok amigos, after lots and lots of time spent with my LT31, I've determined it's definitely a power issue.

My question: How do I get more power supplied to the unit?

a) Can I just purchase a Targus power brick that supplies more than the 30W of the stock adapter (like, say 90W)? I would assume that the power adapter is the PSU on a laptop, but I honestly don't know for sure. I don't want to drop the cash for no reason, but of course =). Guess I could always just take it back if I had to....

b) Is there any way to increase the amount of current the battery can provide? Buying a larger capacity battery would surely just keep the same maximum discharge rate as the stock battery, only increase the mAh available,no?

Thanks guys!

 

If the computer wont run on battery alone and sometimes work/ sometimes crashes/usually crashes when running graphical or extensive tests My assumption is your motherboard/chipset is going bad. A few last things to try would be reinstall of windows except for the fact you said crashes in ubuntu also. Maybe a Bios update/ or even just reinstall of the previous bios then new install of current one. But im 90% positive you need to replace the motherboard. ac adapter/batteries wouldnt help in the case of it sometimes crashing/ not booting. sometimes ebay has decent prices for motherboards.

 

A.) yes you can buy a larger brick but the system has to accept the larger power draw. There is no garenty it will alow the amps needed.

B.) More Mah means the battery is capable of supplying more amps or higher wats. The same issue though as the brick. If the system will not alow those extra amps in then i is a waiste.