Lenovo cg516 nm-a741 no power

[NConstantinou]

HI ALL
i have the above m/b which has 3.3,5 and 19v rail.
i have 3 and 5VALW, 3.3v on BIOS and switch also on pressing power button goes to 0V and back to 3.3v.
EC has 3.3v,RSMRST# ALSO HAS 3.3V but laptop does not switch on.

can someone HELP!!!

Thanks

[mcplslg123]

Re: Lenovo cg516 nm-a741 no power

Do you have a lab supply?? If yes, give us the offline consumption and consumption after pressing Power Button. Is there any change in consumption?? Try flashing bios first.

[NConstantinou]

Re: Lenovo cg516 nm-a741 no power

connecting the power supply the A is 0.00
i noticed something.
on BIOS pin 8 i have no 3.3v and i noticed that on pin 8 is connected to a capacitor then open connection with a test point.
at the test point i have 3.3v.
at the connection point it shouldn't be a resistor!

thanks

[mcplslg123]

Re: Lenovo cg516 nm-a741 no power

I perhaps couldnt understand what you wrote in post#3. Bios pin8 may not have voltage in offline state as DSW is involved in newer mb's. The voltage at bios pin is likely to come up after pressing power switch when mb will try to come out of DSW stage to S5 stage and so on. However, you have not answered my question completely at post#2. Is there any change in consumption after pressing power button??

[NConstantinou]

Re: Lenovo cg516 nm-a741 no power

No there is no power consumption.
i set power supply to 19v with 1.25a and power on and there were no changes
in the readings

[mcplslg123]

Re: Lenovo cg516 nm-a741 no power

With 1.25A board is unlikely to trigger. Set it to 3.5-4.0A.

[Sametbey]

Re: Lenovo cg516 nm-a741 no power

When energized, charge control becomes Self control between IO and + 3.3V STB. Like AC_OK and PWRGD. Are these okay?

[NConstantinou]

Lenovo 310-15abr no power

Dear all

i have the lenovo m/b CG516 NM_A741 Rev 1.0.

i have the 19v , 3.3v and 5v rails
on pin 8 of Bios i have nothing and also at pj704 i am suppost to have 1.8valw and i have .328v.
i tried to find boardview but i couldn't.
can someone help!!!!

Thanks

[mon2]

Re: Lenovo 310-15abr no power

Boardview file is attached.

[mon2]

Re: Lenovo 310-15abr no power

hi.

1) is the bios you are referencing @ UC3 ? Pin 8 is Vcc for this SPI flash. If the voltage is not +3v3 on pin 8, check RC245 - is that - 0 ohm, 0402 resistor present and ok ? Check the voltage on pin 1 of RC245 as well.

2) Aside from the above, in general, power down and place your meter in resistance mode. With the power off, remove the battery. Then check the resistance to ground on each coil. If there is a very low resistance to ground, the rail could be defective due to a bad cap; excessive current draw which may have damaged a local mosfet; dry solder joints on the coil / mosfets.

Any liquid damage ? That must be also repaired.

[NConstantinou]

Re: Lenovo 310-15abr no power

Thanks MOn2 for the reply.

first i tried to download turbo view to have access the boardview because the components on board are NOT labeled but the software is asking to access contacts and other private thinks on tablet which i don't want to do that. do you have brd file!

i already tested all coils and none of them is showing short.
in order to follow ic UC3 (BIOS) pin8 path i need boardview.
Around uc3 there is only one cap and then the rest of the components are on the other side and is connected to the cap again.
on the some side of uc3 near pin 8 there is a connection but no part.
if i jump this connection i think i will get the 3.3v.
i will do this on Monday because today is our EASTER.

Yes you are right customer had water inside

thanks

[mon2]

Re: Lenovo 310-15abr no power

Ok. Understand. My tvw file is encrypted but just 'hacked' the viewer.

1) Download the full package from this shared cloud drive - valid for 7 days from now.

https://wetransfer.com/downloads/53e...1152204/bc44ab

Later on can see about posting this to a permanent link.

2) Then run the boardviewer from the supplied folder. Then load the tvw file shared above.

The process is working for me to view this encrypted tvw file.

Post your results and also check your PM.

Happy Easter

[NConstantinou]

Re: Lenovo 310-15abr no power

Thanks for the file and for your wishes
which part of Canada are you from!

i just checked quickly RC245 location on board.
the only parts that i have at uc3 near pin 8 is cc204.

what do you suggest!

one question when checking the coils.
i noticed some coils cpu for example have low resistance and some others
do not show anything. why is that.

Thanks
maybe i will still some time in the morning to test m/b.
if you are in Ontario province we are 7 hours ahead

thanks again

[mon2]

Re: Lenovo 310-15abr no power

Hi.

1) We are across Detroit, Michigan in Windsor, Ontario so for you it should be around 9:18 PM now (2:18 PM for us).

2) For this SPI flash device (8 pin device), pin # 8 receives its voltage through RC245. RC245 is supposed to be a 0 ohm resistor / jumper. It is important to check the voltage on pin # 1 of RC245 to confirm it is +3v3. Then check pin # 2 of RC245 to be sure it is the same. Since you have no voltage on pin # 8 of the SPI flash device UC3, there is some break in the circuit OR the voltage rail of +3v3 is not present. Either way, these are show stoppers.

3) Please see attached pix which we hope will help you. Need to confirm if the +3v3 is even present on your logic board so start with pin #1 of RC245.

Please post your voltage readings for 1, 2, 3 locations.

[NConstantinou]

Re: Lenovo 310-15abr no power

It is unbelievable
I used to live in university street near Windsor university back in 1988
I graduated from st. Clair Collage as a Mechanical Engineer and then i continued to another college for computers.


Ok I will check everything that you mention and I will get back to you

Nice to hear from you

What is your name!

[mon2]

Re: Lenovo 310-15abr no power

OMG - wait - do we know each other ? Went to U of W at that time - for EE and Comp Science. This is unbelievable? What course did you take? We run a local tech company now and supply the major OEMs (HP, Dell, Philips Medical, Medtronics, all the major airlines...)

[NConstantinou]

Re: Lenovo 310-15abr no power

i was there from 1980-1988.
there is a Pizza place in Pelissier street between Wyandotte str west and Elliott.
i was working there during my studies in order to pay for my expenses for 8 years, at the same time i worked in a company called "Systeman" repairing at that time Amiga and commodor computers , i believe that time were in a Tecumseh mall. i also worked at Jessie's restaurant at university str west and Randolph str

i had a good time there, nice country, nice people.

i am very glad that i met you and brought back memories.

Thanks again.

[mon2]

Re: Lenovo 310-15abr no power

Indeed a small world

I was supposed to work for Atari - was asked by the Tramiel family when I met them @ Comdex. I do believe I recall the place you worked at. If my fading memory is correct - you guys were at the Commodore fest held at Centennial Secondary School? I actually attended that school as well. My parents did not want me to quit University so had to decline the offer to work for Atari. Also Batteries Included / Delrina offered me a job when we met Mark Skapinker (one of the co-founders). Mind you, he was wasted at the Las Vegas party they threw at Comdex Very good memories of the days of Atari, Commodore, early PC business. We paid our tuition by flipping loads of homemade PCs to university students while attending the U of W.

Tecumseh Mall has changed a great deal. Back then it was K-mart then Zellers, both have now gone. Now I believe a s/w company or call-center from India is housed inside.

Our business (35+ years now) is on Tecumseh road and we still do local repairs and were the official Apple repair shop for almost 10 years. They then stopped in Windsor due to low volumes and now only in London & Michigan. Apple is strange. They wanted the stores to have the cure for cancer to sell their products and later when we did many industry first hardware designs, begged us to carry their products. We declined on the sales but did support their service.

Have of our in-house SMT line which we plan to expand in the next year. Can place down to 01005 parts on this line. Next week we will have a fairly high end BGA rework station to remove / replace down to 0.6*0.6 mm parts. We are working with BGA devices that are WLCSP packages of 16 balls in 1.4*1.4mm size. So much to learn in this industry and still designing the next generation of devices. We did the first PCIe designs for the PC industry that caught the eyes of many OEMs. Working on the next roadmaps of widgets but very time consuming and the market is in chaos on available semiconductors.

Miss my Byblo's Donairs (very very tasty falafels) near the U of W. BTW: Shin Shin is still around Great place and a 'kid' from TO is the new owner. The original owner retired about 2-4 years ago. The recipes remain the same - great food and great service. The owner is a real pro and can memorize your likes / dislikes by customer name. A friend of mine owns the Sam's Pizza near the U. They have been around since the early 70s.

Need to work on a time machine next and stop this crazy virus...

Back to topic - hope we can get your unit working or at least give it our best try. Bye for now

[NConstantinou]

Re: Lenovo 310-15abr no power

Thanks again for the memories.
i must tell you that i had a spend a wonderful life there

i am sending you a file of parts missing around pin 8 of bios.
i am waiting for your suggestion.

pin 1 of RC245 has 3.3v cap and pin 8 of bios 0v.
should i bridge something.

Thanks

[mon2]

Re: Lenovo cg516 nm-a741 no power

hi. my apologies, the referenced ROM @ UC3 is powered from +1v8 (not +3v3). See attached partial schematic.

Please confirm the presence of RC246 and also that the voltage rail is +1v8. If not +1v8, then there is an issue with that voltage rail.