Seagate 5400.6 head compatibility

[popowoo]

I have two Seagate 5400.6 HDD.

One seagate 5400.6 HDD
ST9500325AS
PN : 9HH134-231
FW : 001SDM1

HEAD : WY4-T / TICB-B

Another seagate 5400.6 HDD
ST9500325AS
PN : 9HH134-231
FW : 001SDM1

PN,FW are all same. but head part NO. WY4-P / TICB-P

I have tried to replace each normal Head but failed.
I would like to know why should not compatible with the same PN and FW.

Please answer my question.

[jono-ats]

The part numbers may be the same, but the topography of the sliders may be in fact different. You have to compare them under magnification to get a true match.

[popowoo]

then, How to interconvert each other?

[labtech]

No feasible method to convert between them, or at least not in a physical manner. It is just like any other part applications in other industries.
The part either is compatible or not.