Need help with a difficult APU upgrade.

I have a HP Pavilion G7 (1328dx) with A6 3420 APU. I have read on this forum about people upgrading their APU successfully and thought I'd give it a shot. I purchased (from a reputable company) an A8 3550 and installed it in my laptop. When I tried to boot up, the screen stayed black and the keyboard LEDs flashed the code for "bad processor". I took everything apart and reseated the APU and did a hard reset with the CMOS battery unplugged; but got the same result when I tried to boot. I put the A6 3420 back in and the laptop worked perfectly; so I flashed the BIOS to the current "6a" version. I installed the A8 3550 again and still the blank screen with keyboard flashing code for bad processor.

I don't know what to try next. I have no way of testing the APU to find out if it's functional or if it just doesn't like my laptop. I have recently read that HP laptops are notorious for not recognizing or allowing any hardware changes, even wifi cards or solid state drives. I have seen people here upgrade the APU in their dv6 model laptops though.

I wonder if my laptop needs reset to it's factory state before upgrading the APU? I think others have upgraded without doing a reset though. Maybe the A8 3550 is non-functional, but I'm fairly sure it was tested before they shipped it and the container wasn't damaged.

Hopefully someone that has successfully upgraded a socked FS1 APU can help. Thanks.

 

There doesn't seem anything else to test here; that cpu simply doesn't work with your system.

No need to reset/re-install the O/S: the problem seems to be even before the computer posts/boots.

Return it for a refund if you can.

 

I've changed APU in so many HP laptops and never had any issue. So if A8-3550MX not booting up, than either the APU faulty or your system memory cannot run 1600MHz properly (if you have 1600MHz RAM).

 

Thanks for the quick responses!
I have been considering returning it; but, without another laptop to test it in, I'm afraid the APU is actually functional so the company will hit me with restocking fees and such.
I forgot about the memory (no pun intended). I haven't upgraded to good memory yet; it's still running the 1333MHz ADATA 4GB stick it came with. Could that be the problem then? I didn't know the A8 3550MX had to have 1600MHz memory. I thought it would just increase performance when I eventually get two 1600MHz SODIMMs.

 

The CPU would just scale to the memory's clock, so I think your 1333mhz memory is a non-issue. Does your laptop have models that go with the A8 preinstalled?

 

Yes, the A8-3550MX support 1333 and 1600MHz RAM too. I thought you maybe have 1600MHz RAMs, which would like to run that speed but have problems there. Obviously with 1333MHz RAMs it is not the case, so the APU is the faulty. Send it back!