A1181 coreduo => core2duo upgrade cpu

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

CPU rails have got always low resistance....eg. 10-15ohms (If CPU present)

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

so ive been probin around lol.

they seem shorted but gotta take them out my soldering irons plug is being used by oven atm for cooking food not mobos lol.

i also been looking at caps in diode mode and most of them beep quickly and are good, i assume its due to it getting charged.
but some just keep on beeping i could tell you which ones do and which ones dont but they are just random all around.

but this could also be due to bad bga again.

when i eat and get my power socket back ill pull them coils out and probe again.

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

CPU rails have got always low resistance....eg. 10-15ohms (If CPU present)

Can you give me a bit more detail on this im a bit of a noob and dont understand completely the terminology. eg cpu rails ....
you saying that the resistance between the +vcpu and ground will be low anyway wid the cpu in.

im learning everyday with the rest of the noobs here.

love the input thanks

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

What I mean, is the coils near CPU will read low resistance (when CPU present)...
Since you have bga soldered CPU, that's the same as it would be in socket obviously...
I meant CPU rail as VCORE or VCCORE voltage...
I would get the schematic first and start from there...

BTW I'm also noob...

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

been looking its hard to find.. nothing is marked on the board id be lost but ill try to find something

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

You got apple part number near the sodimm slot(right one)
There's also another number but can't read it properly...
It's either K36, K36C or M42B board...(never worked on macbook,so not sure, hate that crap,lol)

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

OK...

According Apple part no. it should be this 1...

You're saying that L7500 & L7501 are shorted?

It's on CPU VCORE PWR rail, so I assume they're OK,but desolder & check which side/pin is shorted...

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

As far as checking caps in circuit in "diode mode beep thing" why would it keep on beeping apearing to be shorted? i mean some right next to the ones that beep forever just beep quickly and go off.

and the ones on the parts board with no cpu or nb installed beep quickly and stop.

any ideas

thanks

by the way the schematics, site, and so for GREAT thanks a lot.

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

I hope you're testing them with no PSU connected...

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

yeah no psu connected.. the beeps am i checking it right?

as far as those other caps that blew you reckon its because of the heat in the reflow?

why would they just start melting lol

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

what caps???

could you tell me the schematics marking (all of them)...

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

how did you do reball???do you have proper BGA machine...what's your bottom heater settings?

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

the thing is i cannot identify them on the schematics, but they are the ones in the pictures marked red earlier in the thread
and the black one im holding with my thumb was one of the ones blew.

[loser18]

Re: A1181 coreduo => core2duo upgrade cpu

jeeez....even the coil is melted...I think you've shorted cpu with some other rail & that caused all of the caps to blew...

[stj]

Re: A1181 coreduo => core2duo upgrade cpu

the cpu is on the right way around i hope!

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

i set the bottom heater at 170 - 180 and wait till it hits that on top tc

but my tc for my bottom heater pid was pointing away from the heatin element and therefore not reacting as quickly.

im gonna replace some more caps and see what happens then ill try a reflow and back on the old cpu if that dont work.

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

jeeez....even the coil is melted...I think you've shorted cpu with some other rail & that caused all of the caps to blew...

what coil is melted? am i blind lol

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

so i poped these coils next to cpu out and they test very low resistance 1.0. same as on my parts board. idk how to test these.

i couldnt tell which side it was on or how to tell. i hope u can clarify a tad bit for me.

thanks for the patience

[drdyzio]

Re: A1181 coreduo => core2duo upgrade cpu

the cpu is on the right way around i hope!

yeah lol
cpu is right way round..

[tom66]

Re: A1181 coreduo => core2duo upgrade cpu

Inductors WILL test as low resistance - they are a coil of wire around a magnetic core (although a power inductor may be different, the principle is similar, direct electrical connection at DC.)