can you help 820-00840-A no keyboard typing laptop works

[mgjini]

hello all

i have got this macbook 820-00840-A which it doesn't have backlight on keyboard but also i can not type, so if i was to do nvram reset by hodling pressing power button and hold opton command +r +p macbook resets and comes on with chime, also if i turn off and on power on to hold option command + r internet recover comes up i choose wifi with trackpad which works but i can not type, capital letter R light doesn't light up

i have replaced j4810 2 times and it is not that all the pins are soldered

j4810 measurements connected to keyboard laptop on

pin
1. 5.1v
2. 0v
3, 3.295v
4. 0v
5. 3.417
6. 0v
7. 0v
8. 0v
9. 0
10. 3.293
11. 0v
12. 3.306
13. 0v
14. 3.306
15. 3.423
16. 0v
17. 0v
18. 3306
19. 5.1
20 5.1

R4801 0.390v
Q4800 PIn 2 0.399v, pin 1 3.10v pin 3 0.399v
r4821 0.152v

any help please

[petehall347]

Re: can you help 820-00840-A no keyboard typing laptop works

did you try an external keyboard ?

[reformatt]

Re: can you help 820-00840-A no keyboard typing laptop works

I2C lines for the keyboard also go to the trackpad. I have seen a bad trackpad on the earlier models (A1502 etc) cause keyboard not to work. So try with a known good keyboard, trackpad and cable then inspect around J4801 as well.

[mgjini]

Re: can you help 820-00840-A no keyboard typing laptop works

did you try an external keyboard ?

Hi sorry I forgot to mention, I have tried with external keyboard and works fine, I have tried with another complete palm rest and same story can not type