HP Compaq 6735s upgrade problems

[cesedy]

Hello.
*I buyed a new motherboard ( http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250475946552&ssPageName=STRK:MEWNX:IT ). And I want to upgrade my laptop. I have AMD Sempron SI-40 processor and 1GB RAM. So I buyed a AMD Turion X2 Dual-Core RM-70 processor ( http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170365484490&ssPageName=STRK:MEWNX:IT ). I was looking on both processor specifications and Sempron ( http://www.cpu-world.com/CPUs/K8/AMD-Mobile%20Sempron%20SI-40%20-%20SMSI40SAM12GG.html ) looks the same as Turion ( http://www.cpu-world.com/CPUs/K8/AMD-Turion%2064%20X2%20Mobile%20technology%20RM-70%20-%20TMRM70DAM22GG.html ). Even voltages are the same. Only difference is that Turion has 2 cores
*So first, when I putted processor (RM-70) and turned laptop on, everything was normal. It showed HP logo and started to load Windows XP, but failed, because I needed to change SATA settings into BIOS to IDE. And to make sure, that processor is ok, I went into System Information. And at processor section it showed my RM-70 processor. But when I turned around, and about 30 seconds I went back, screen was blinking in black and white. So I turned laptop off and on. After I turned it on, screen remained black and HDD led blinked in orange and DVD drive LED was blinking. But when I change processor to SI-40, everything works fine.
*I was contacting HP Support Centre, and they said, that upgrade is not possible, because every motherboard supports only one processor type. I don`t believe them, because if my motherboard doesn`t support Turion processor, then it wouldn`t start even at first time.

So, can anyone please help me to understand why I can not upgrade my laptop with Turion processor?
Thanks.

[andamus]

Try to upgrade the bios to the last version.
One problem that can arise is that the original cpu cooling sistem was not designed to handle a dualcore cpu.