[SOLVED] G61 Randomly Stops Taking Mains Input

[Adept PC Repair]

Hi,

Another one of those strange ones here again!

I have a HP G61 (intel chipset) with a strange AC problem.

The laptop works fine, but after about 5 minutes of being on the mains it will then stop taking power from the mains.

No amount of wiggling solves the problem, the DC Jack is fine (on a cable). This is their 2nd battery and charger and they have the same symptoms.

I've taken a look at the capacitors on the board, none seem damaged. I even replaced one for the hell of it.

I have no clue why this is doing it. I've resoldered the connector to the motherboard just to ensure that when it gets hot it doesnt all of a sudden get a bad connection.

Anyone seen a similar problem?

 

[markcuk11]

at what percentage is the battery charged I have an HP and it does not start charging till under 95%

 

[Adept PC Repair]

The problem still occurs if there is no battery installed.

It seems to occur when the system is under stress only, I can leave it on without a hard drive in for ages, as soon as I fire up heavyload it will stop anything coming through the mains. It is not overheating however as I have cleaned everything up, and of course if the battery is installed the machine continues to stress test, just on battery power.

I'm thinking I might just have to tell them it needs a replacement motherboard, i've tried fault finding and just haven't got anywhere. If i actually charged the amount of time i've spent on this it would equal to a new motherboard anyway.

 

[markcuk11]

is the new charger a original or universal? could be set to 18v instead of 18.5v?

 

[Adept PC Repair]

The new charger is an original, the only reason they replaced the old one was due to this fault.

It's as if there isn't enough power getting through on heavy load to charge the laptop, it needs to take it from the battery.

 

[markcuk11]

I would try a universal one if you have one you just never know! and I would also try a bios update

if not probrably motherboard problem.

 

[anonymous Mac Tech]

at what percentage is the battery charged I have an HP and it does not start charging till under 95%

This is normal behavior for most laptops to avoid unnecessary charge cycles onto batteries shortening their life and charge capacities. On Macs for instance the battery has to be below 95% on a PPC Mac and below 93% on an intel.

But on the original issue, what about the drive and RAM in the machine? Has it been thoroughly tested/swapped? I'd imagine a short somewhere and might as well start ruling things besides the main board that are shorting out.

 

[Adept PC Repair]

The ram I really can't see causing this problem, or the drive, i'll try removing the hard drive and booting from a winpe cd, swapping the memory and using mu universal charger.

This seems like some sort of chipset fault to me, if the laptop is off, the fault never occurs, i'm clutching at straws here though.

Bios update is also worthwhile I agree, though it may fail as they don't like being on battery power

 

[PC-MOT]

Does it stop drawing and let itself run out of juice or does it start drawing again when it gets low?

 

[Adept PC Repair]

It completely drains, even if a battery isnt installed it will just switch off.

 

[PC-MOT]

Well if you ruled out charger and dc jack, and you update bios, i'd go with mobo. As you say you can keep going for days with fault finding!

 

[sys-eng]

The problem still occurs if there is no battery installed.

I'm thinking I might just have to tell them it needs a replacement motherboard, i've tried fault finding and just haven't got anywhere. If i actually charged the amount of time i've spent on this it would equal to a new motherboard anyway.

I pride myself in always being able to fix any computer problem EXCEPT for a motherboard. I rule out everything else, then it must be the motherboard. i do wish I had a more certain way to test them though.

You say it happens under stress; therefore, it is probably heat related on a chipset. There may be heat safety options in the BIOS that you can turn off to test this. If this makes a difference, it may just be a defective thermal sensor on one of the chipsets that is shutting down the system. Most OEM BIOS are locked so we cannot turnoff such thermal settings which means a new motherboard is probably the cure.

 

[Adept PC Repair]

I do not think this is the case, as the laptop does not turn itself off if there is a battery connected, it just uses the battery power instead.

I don't want to give up with this one, i have it running next to me at 2am on my birthday haha. I just don't like being beaten, I especially don't like charging for motherboard replacements and would rather do things smd level if necessary.

 

[sys-eng]

I do not think this is the case, as the laptop does not turn itself off if there is a battery connected, it just uses the battery power instead.

I believe you are referring to using battery with no AC adapter connected. In this power mode, it is nearly impossible to "stress" the system unless you change the power mode in power managment. "Battery Only" mode reduces the CPU clock and other things to reduce power consumption.

 

[Adept PC Repair]

I've ordered a replacement board, should be here tomorrow.

 

[Adept PC Repair]

Just to update everyone, a new motherboard solved this fault.