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PB 100 lifted pad and mosfet

bengi3

Well-known member
I am about to recap this logic board but the capacitor at C104 has a lifted pad and one mosfet (is it a mosfet) is missing.

Two questions: 1) where can I get to continuity to the missing pad? 2) Cannot get to find this NEC J143 mosfet.

image.jpeg

 

80sboy

Member
You sure that pad is gone? You've cleaned it up with flux and new solder and desoldering braid with a chisel tip? Maybe probe C102 to see where it goes and that will maybe help get you in the general area. Good luck! I wish I had a working PB100 - recapped my board which was a total PITA, recapped the screen etc and still have the dark blue screen argh...

 

bengi3

Well-known member
Btw, those three mosfet are weird. I tested by removing them from the logic board (more than one logic) and they seem all shorted, i.e. the gates (G) are not discharged after touching with the finger.

 
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bengi3

Well-known member
I agree with 80sboy, if you are talking about the left pad.. this is connected to the right pad of C102, if you are talking about the right pad of C104, scratch the solder mask to get a clue.

J143 is a Mosfet

https://french.alibaba.com/product-detail/power-mosfet-j143-transistor-to-220fp-2sj143-60733054661.html

The fuse is also missing
Ok, its the right pad. BTW regarding the mosfet how come that in each and every logic board that I am testing they all seem shorted? 

 
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