Problems after replacing Battery and Trackpad- MacBook Pro 2012

[Charlyem]

Hi Everyone,

I recently bought a 2nd-hand Macbook Pro 2012. My previous computer was the same model,I was happy with it because I could replace most of the parts and I thought buying another I could reuse some parts of the old one.
The Story:
1 - The computer I bought worked fine but the battery lifetime was shorter than my older one
2 - The trackpad was also worst than my old one
Then, I decided to change both parts and replace them with those of my old computer

The Result:
1 - The trackpad works but the system doesn't recognise it
2 - The system neither recognizes the battery, therefore it doesn't charge (the computer works plugged)

We've tried:
1 - to use the battery inanother laptop and it works
2 - to replace again with the original ones and the same problem persists
3 - to reset nvram and smc and the problem persists

Any idea? It doesn't seem a hardware problem but I have no idea how to solve the software issue

 

[chscag]

Welcome to our forums.

It sounds like there may be a problem with connectors or cables. A MacBook Pro from 2012 is going on 8 years old, connectors and cables wear out even though they look okay.

Suggest going to this US site: www.ifixit.com Look up your model MacBook Pro and go through some of the disassembly instructions and photos to see if you can narrow down what the problem may be.

 

[Charlyem]

Welcome to our forums.

It sounds like there may be a problem with connectors or cables. A MacBook Pro from 2012 is going on 8 years old, connectors and cables wear out even though they look okay.

Suggest going to this US site: www.ifixit.com Look up your model MacBook Pro and go through some of the disassembly instructions and photos to see if you can narrow down what the problem may be.

Hi,
Thanks for your answer. I already followed the guide.
Regarding your connections suggestion, I'm almost sure it's not that because of the following reasons:
- Both connections were working fine until I gently replaced both parts
- It would be weird that both have the problem at the same time
- I can move the arrow with the trackpad so the connection seems to work but the system doesn't recognize it.

 

[techiesteve]

If both batteries are seen in another Mac, and the SMC has been reset, then it's likely the logic board has developed a fault. Why, I've no idea. At least it's still useable.

Is the MBP a 13 or 15"? If a 15" the trackpad cable runs under the logic board. Some users disconnect the flex cable from the trackpad rather than removing the logic board to replace remove and replace. Apple advised not to do this, this being why Apple trackpads are supplied with the flex cable attached. If your MBP was a 15" and the complete trackpad assembly wasn't replaced, this may have introduced a fault.