Dimmed green light on 820-2915

Yustina

New member
The resistor is blowing because too much current is being drawn into u7000. The chip could have a internal short to ground.

Replace r7005 with u7000. But before you do this, does this machine work from a battery ?

whats diode mode reading on l7030 ?

I have replaced u7000 already, maybe like 3 times (of course, from donor boards) but in the end, the same result, bright green light then dims to a very low one. Machine does not recognize the battery so, dead on battery as well.
Diode mode on reading on L7030 is pin 1 and 2 are zero V, pin 3 is OL

Would D7005 make a difference if I replace it?

This machine was mine and died all of a sudden.
 

Gurmon

Member
ok, so you have a short on ppbus_g3h. forget pin 3 its not connected.

Remove L7030, see which pin 1 or 2 the short is on.

What I used to do in the early days, is measure all the voltages and diode mode readings of ALL rails, This way you would have seen issue on ppbus_g3h without ever removing anything.
 

Yustina

New member
According to me ( :/ ) I have tested ALL RAILS but again, I am sure I missed several important areas, I am getting better though, thank you for the tip. I have removed L7030 and measurement on diode mode for pin 1 is .430v , pin 2 is still 0v
 

Gurmon

Member
okay, short is on the system side. Do you have a means to inject say 3V @ 1A into pin 2 where L7030 was installed ?
 

Yustina

New member
holy shit! this is starting to make more sense now, reading you and looking at the schematic.... yes, I have a power supply here, need to find wires..... ok, I have seen videos of Louis R. about this, will follow and test for hot areas..... Thanx so much man! I will post my findings! =)
 

Yustina

New member
Ok, I was able to connect my power supply but unable to inject more than 1.4V, regardless of amperage. My power supply is regulated and I am unsure if this has anything to do but it would not go over 1.4V, I will figure this one out later. When I had that voltage, I did feel L7630 get hotter than other components, removed it and short was still there and since 1.4V I feel is still too low then I am still somewhat where I was. There is however, this buzzing sound being emitted louder from the cougar point U1800. The only thing I can think is that somehow my AC is not being regulated efficiently into DC and since the inductors are the ones that carry out this task, I am thinking on focusing on these harder. So, problems until now, no STRONG green light on charger and buzzing sound from u1800. Again, anybody feel free to pitch in, Gurmon: what do you think?, Duke: I know you probably dont have the patience for this, lol.
Thanx in advance
(p.s. I am looking for guidance in what to look for, not for anybody to solve my problem for me, I have followed the schematics to the best of my abilities and without being able to get questions answered I will not do a good job at interpreting the same)
:D
 

Gurmon

Member
Its up to you to find the short, only you can feel what is getting hot. Its unlikely L7630 is heating up.

Buzzing sound from the PCH doesn't sound good. You sure its coming from there.

Keep trying............
 

Yustina

New member
Its up to you to find the short, only you can feel what is getting hot. Its unlikely L7630 is heating up.

Buzzing sound from the PCH doesn't sound good. You sure its coming from there.

Keep trying............

I will figure out the deal with my power supply then inject up to 3V and go from there. The buzzing is stronger on the U1800 area but not sure if its coming from there..... i will keep trying, thanx for your help so far!
 

Yustina

New member
OK so you've got PP3V42 then.
You still got dim green light?... If so have you got SMC_BC_ACOK on pin 2 and 1 on U6901? voltage at pin 1 and 4 of U6900?

I have no smc bc acok, i believe voltage on pin 4 of u6900 is around 16V, will measure and post again as soon as i get home
 

Yustina

New member
OK so you've got PP3V42 then.
You still got dim green light?... If so have you got SMC_BC_ACOK on pin 2 and 1 on U6901? voltage at pin 1 and 4 of U6900?

Ok, finally have time to get to this, I measured for smc bc acock and I had it, I followed the line all the way to Q5310 and when measuring this, U6901 fried with hole in the middle and all, I replaced twice and NO smc bc acok any longer... I am fixing on getting another power supply and I N J E C T!
Still get 3.5 on L6995
 

dukefawks

Administrator
I'm going to be honest here. This board is total toast. If it wasn't already you have now shorted 12V to the ACOK line at Q5310. This will have taken out the SMC and everything on that line including the ISL6259. You cannot make mistakes like this, this board is pretty much beyond hope now for sure.
 

Yustina

New member
I'm going to be honest here. This board is total toast. If it wasn't already you have now shorted 12V to the ACOK line at Q5310. This will have taken out the SMC and everything on that line including the ISL6259. You cannot make mistakes like this, this board is pretty much beyond hope now for sure.

Yes, i figured so far after staring at it for a while. It was a good learning project and will definitely not make the same mistakes, thats for sure. Thank you
 
Top