Troubleshooting: Lenovo Motherboard

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

Hmm, that is a possibility. It's also 10k. But that still has no continuity to PIN 16. An no continuity to QE2.

p330 continuity to pin3 pq309 ( first or second side )and other side continuity to pin16 ,I suggest it's pr330 ,measure voltage in and out ? if one side is connected to pin3 pq309 so it's sure pr330( because the other one in last post with continuity to qe2 it's pr331) the other side should be connected to pin 16 ,if no continuity to BQ24737_VDD = pin16 ,so make a jumper .

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

Lets refer them to old P330 and new P330 (old the one that is marked in the photo, new is the one you've asked about)

Both have continuity to PIN 3 PQ309.
None have continuity to PIN 16 BQ24737.
None have voltage in/out.

p330 continuity to pin3 pq309 ( first or second side )and other side continuity to pin16 ,I suggest it's pr330 ,measure voltage in and out ? if one side is connected to pin3 pq309 so it's sure pr330( because the other one in last post with continuity to qe2 it's pr331) the other side should be connected to pin 16 ,if no continuity to BQ24737_VDD = pin16 ,so make a jumper .

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

i resume it with this picture ,

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

no old no new pr330 just refer to the picture i have mensionned, it's correct

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

I checked continuity from the PD303 (the pin you've highlighted) with DC in. And there was continuity almost everywhere on the board. PQ302 even, one one side only, and PR330, PR331, etc...

I'll make a jumper. Can I use any wiring (i.e. from a desktop PSU)? Cause I don't have proper jumper wire (it's on delivery still)?

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

I checked continuity from the PD303 (the pin you've highlighted) with DC in. And there was continuity almost everywhere on the board. PQ302 even, one one side only, and PR330, PR331, etc...

I'll make a jumper. Can I use any wiring (i.e. from a desktop PSU)? Cause I don't have proper jumper wire (it's on delivery still)?

voltage on pd303 pin 2 it's 6v (pin 16)not dc in , according to the schematic pin 16 should be connected also to the commun side of pr330 (10k) and pr329(47k),that mean you should find this 6v in the commun side of those resistor

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

i hope that will make things clear .

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

Yes yes I know what you mean, you were very clear My DC in was meant to be DC connected.

Can I cut a piece of wire from a desktop PSU and use that temporarily since I don't have the "proper" jump wire?

voltage on pd303 pin 2 it's 6v (pin 16)not dc in , according to the schematic pin 16 should be connected also to the commun side of pr330 (10k) and pr329(47k),that mean you should find this 6v in the commun side of those resistor

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

when you check continuity and resistance mode or diode mode you should disconnect the DC input ,DC input just to measure voltage ,so re measure the continuity like a explain on PDF to the commun side of pr330(10k) pr329(47k)
you can use it like a jumper just for testing but it's not the corret way but before that remesure .

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

Did the jump wire, now I have 19V on PQ302.

when you check continuity and resistance mode or diode mode you should disconnect the DC input ,DC input just to measure voltage ,so re measure the continuity like a explain on PDF to the commun side of pr330(10k) pr329(47k)
you can use it like a jumper just for testing but it's not the corret way but before that remesure .

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

good now you have your B+, SECOND step check always voltage +3valw (pj402) and +5valw (pj406)

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

PJ402 is receiving 3V
PJ406 is receiving the 5V

good now you have your B+, SECOND step check always voltage +3valw (pj402) and +5valw (pj406)

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

check 3 volt present on power button ?

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

Yes it is

check 3 volt present on power button ?

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

so good,now try to power on the mobo and see if there is picture on the screen ( don't assembly the cable screen with DC input connected ,BE CAREFUL disconnect DC input and battery before assembly screen cable )

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

That would be too easy :P It however powers on for a second, then it goes off.

I proceeded to check the 1.35V, and it seems to be missing. Not sure if this is the proper way to troubleshoot this next issue.

EDIT: battery was not used in the process, only DC (after screen was connected).

so good,now try to power on the mono and see if there is picture on the screen

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

so check resistance to ground for +1,35 line (pj502)?

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

I don't understand what resistance to ground means, but it's 0.375.

so check resistance to ground for +1,35 line (pj502)?

[kiraro]

Re: Troubleshooting: Lenovo Motherboard

I don't understand what resistance to ground means, but it's 0.375.

that mean black probe to ground and red probe to pj502 and meter in resistance mode (without DC in ) what do you get ? you mean 0.375 ohm?

[DanFen]

Re: Troubleshooting: Lenovo Motherboard

By now I know how it's measured, but I don't know what it means i.e. what we're testing and how do we conclude it's good or bad.

Yes ~0.375 on PJ502/3. Makes sense?

that mean black probe to ground and red probe to pj502 and meter in resistance mode (without DC in ) what do you get ? you mean 0.375 ohm?