Missing CMOS battery

[sorcerer]

A friend's son thought he would be helpful and tried to repair his mum's laptop. It's a Lenovo Z50-70 and the motherboard is etched with the markings ACLUA/ACLUB NM-A273 Rev 1.0.

I don't know what symptoms it was presenting before he took it apart but my friend has just presented me with a cardboard box full of bits, stripped down to the motherboard (protected in a cardboard sleeve) and a glass jar full of screws!

Something must have pointed him to the CMOS battery because he's desoldered it from the mobo and it's missing, which is where I need help. Does anyone know what sort of coin cell should be in there? As it stands I don't even know if it's a rechargeable one or not and no idea of catalogue number.

One photo below shows the empty space where it should be and the other picture I managed to find in the wild with the sort of battery that's needed.

 

[mikeroq]

Should just be a standard 3v lithium rechargeable battery. No different than a normal CMOS battery just in a different package. Some solder to board, others have battery on a lead, some have holders for CR2032, others have no battery.

https://www.digikey.com/product-det...-of-fujitsu-group/ML1220-TJ1/SY104-ND/1202948

Measure the spacing of the solder pads and compare it.

 

[sorcerer]

Brilliant, cheers Mike

 

[Porthos]

I don't know what symptoms it was presenting before he took it apart but my friend has just presented me with a cardboard box full of bits, stripped down to the motherboard (protected in a cardboard sleeve) and a glass jar full of screws!

Hope it works out ok for you. Many here including myself wouldn't touch that job with a 10ft barge pole.

 

[Moltuae]

Many here including myself wouldn't touch that job with a 10ft barge pole.

Personally, I wouldn't touch it with an 8 inch soldering iron.

I find those 10ft barge poles really difficult to solder with

 

[sorcerer]

The only reason I'm doing it is that my mate and I met each other on our first day at infant school, aged 5. We are now both 61 and have been friends all that time, regularly meeting up at least once a month for a few beers - otherwise I wouldn't touch it either

 

[Porthos]

The only reason I'm doing it is that my mate and I met each other on our first day at infant school, aged 5. We are now both 61 and have been friends all that time, regularly meeting up at least once a month for a few beers - otherwise I wouldn't touch it either

Those repairs (friends/family) are usually the ones that take the most time and often come back to haunt us.

 

[NETWizz]

A jar full of screws... that will be fun if they aren't all the same size! Then of course there is an order for assembly and disassembly for which parts come off in which order. Naturally, a good Technician diagnoses the problem before taking it apart with the scope of disassembly being to replace a specific part.

Let's say you spend the time and sort out all the screws and parts, attach a battery and get it back together, which will take twice as long when you didn't take it apart... You still have to diagnose the original problem and repair that. I figure a competent technician takes about an hour to an hour and a half to replace a laptop motherboard. It is going to take you about two hours just to get this thing back together, and until then you won't know if your solder job works.

If I were doing this job for pay, I would quote your motherboard replacement fee plus one additional hour labor.


P.S. If you want a free CR2032, I will be happy to mail you one though I don't know how long it will take with a Global Forever stamp to make it.

 

[Larry Sabo]

The service manual should help. It also identifies the order and size of screws. That's one thing I like about Lenovos -- support documentation.

 

[sorcerer]

The service manual should help. It also identifies the order and size of screws. That's one thing I like about Lenovos -- support documentation.

That's brilliant, thanks Larry.

NETWizz - I'm not doing it for money. Like I said earlier, we've been lifelong friends so we've agreed on a night out and all the beers, plus curry or kebab on the way home, plus taxi and he's picking up the tab

 

[Markverhyden]

I'd push for a vindaloo.

 

[Moltuae]

I'd push for a vindaloo.

Nooooo. That could end badly!

 

[Markverhyden]

Nooooo. That could end badly!

Too funny. That's exactly what popped in my mind. It's one of the better episodes.

 

[brandonkick]

Should just be a standard 3v lithium rechargeable battery. No different than a normal CMOS battery just in a different package. Some solder to board, others have battery on a lead, some have holders for CR2032, others have no battery.

https://www.digikey.com/product-det...-of-fujitsu-group/ML1220-TJ1/SY104-ND/1202948

Measure the spacing of the solder pads and compare it.

Rechargable? I'd tend to think it wouldn't be a rechargeable battery?

 

[fincoder]

Some modern laptops don't have a CMOS battery installed at all, especially models that have a non-removable main battery. Because the main battery isn't removable the CMOS almost never loses power, only when the battery is completely flat or faulty. The CMOS is designed so the loss of battery backup doesn't cause issues, and the date/time is only out by the elapsed time without power (until the OS updates it from the internet).