Toshiba Satellite C655 won't run off AC. Need schem.

[inflex]

Hi all, I'm an EE so talk exotic, no problems there.

I've got a motherboard out of a Toshiba C655 which is designated MN10R-6050A2423501-MB-A02, that in itself is one of the problems, seems everyone has the G45 / MAS10M type schems but no one has the NM10R type.

Now, to the actual fault...

If I put a charged battery into the system it shows a battery light and I can boot fine, but it does not seem to take charge from the power brick / powerbrick-IN.

Once the battery runs out, everything shuts down, even if the powerbrick was active.

My "theory", the ACIN sense is dud or something connected to that, the trouble is, all the parts on this board are DFN, MLF or QFP size and as such the numbering on the parts are essentially useless and it'd be great to get a schem / board-part-map to track back.

I've already put the whole board through one reflow process to no avail, so it wouldn't seem that we're dealing with an obvious joint issue, at least not initially.

In summary... anyone got a schem for this board?

Thanks in advance.

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

UPDATE:

I've been probing around the charge/power-selector chip (Ti BQ24725 QFN chip) and noticed it seems to be behaving normally, shows ACIN, correctly changes the ACOK status pin when I alternate between having the powerbrick connected or not. The battery -appears- to be charging up when the unit is off (waiting another 15 minutes to see if it's actually charging or if it's just the cells recovering).

HOWEVER, when the unit is ON, it does not charge, the power all seems to come from the battery only and no load appears to be drawn from the DC power pack.

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

UPDATE:

I think I've found the problem, my Q6002 MOSFET is showing shorted, which I -believe- is the RBFET as per the sample schematic provided by the TI datasheet for the charge/power controller at - https://cdn.badcaps-static.com/pdfs/...daef662536.pdf (the controller is the QFN marked just as BQ725 to the right side of the image).

2am here, I'll replace this MOSFET in the morning, standard SO8 type, shouldn't be a problem. Hope it works after this.

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Replaced the MOSFET this morning - all seems to be working again normally.

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Machine assembled and all working 100% now

Used an IRF8113, had a few of them and it has better specs overall in this case, so no harm.

[easy400tech]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

I want to thank inflex for his above posts. Recently a friend's C655 laptop died (DEAD! just past end of warranty). Toshiba wanted $354US to fix. I ran across your post, downloaded a bq24725 data sheet, did some tracing and verifying. Q6002, N4800LS (RBFET on bq24725 datasheet) was bad (shorted). Ordered a IRF8113 from Newark Electronics for $.76 (+freight), soldered it in and the laptop boots like new, battery charges and everthing. This repair is not for everyone but I greatly appreciate the posts because without them, I would never have been able to trace the problem.
Thank you "inflex" and Thank you "Bad-Caps" for making this forum possible.

[lord]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

I love a happy end!

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Good to know Congrats there Easy400tech.

Sadly tonight, another L300 went in to the bin, even with the NEC-TOKIN replacement it still wasn't good, no point wasting time on it :\

[evanesce]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

question, with the DEAD MOSFET, do you remember when the battery died, it wouldn't even begin to charge it again?

To get mine going after a full battery failure, I have to jump start charge a little the battery using a car battery 12v source for a minute, then it will begin to charge only while the machine is off.

Wondering also, how do you test to see if the MOSFET I have is indeed bad like yours was?

[ksavage68]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Inflex, just want to thank you for the great work. I had the SAME issue with a friend's Toshiba and I ordered the chip and installed it today, works perfectly now. But man, that is one TINY chip.

Keith

[sparker1]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Hi Inflex. Thanks for the info. I am in Mackay. Let me know if you need any bits and pieces or help.

[sparker1]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

question, with the DEAD MOSFET, do you remember when the battery died, it wouldn't even begin to charge it again?

To get mine going after a full battery failure, I have to jump start charge a little the battery using a car battery 12v source for a minute, then it will begin to charge only while the machine is off.

Wondering also, how do you test to see if the MOSFET I have is indeed bad like yours was?

Try this info: https://www.badcaps.net/forum/printthread.php?t=7726

[helio]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

i want to know if you have o program the BQ24725 or just to buy it and then just to weld to the motherboard

[inflex]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Hi Inflex. Thanks for the info. I am in Mackay. Let me know if you need any bits and pieces or help.

Will do Hope it's all good down there

[rievax_60]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

i want to know if you have o program the BQ24725 or just to buy it and then just to weld to the motherboard

No programming required. It gets controlled by the SMBus.

[shaker31280]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

I have a C655 same motherboard. When I plug in the AC I get no lights nothing. If I plug in the battery and press the power button I get 5 flashing orange lights. The computer never turns on.

I am guessing this same chip is the issue, but I am trying to figure out how to test it. Reading the link above people added already.

Did you have the same issue?

Then also where to buy it. I checked around and can't seem to find a replacement (IRF8113). Any ideas?

[shaker31280]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Testing Q6002, if I am doing this correctly. It has 8 legs, 4 on each side.

For number purposes I show the leg numbers below.

1 2
3 4
5 6
7 8

If I use a multimeter and check for resistence between 1-2 I get 0, 3-4 I get 0, 5-6 I get 0, 7-8 I get 0. 0 being its opened.

If I check Q6003 the same way I get some resistence, the meter goes from 1 to .102, .09, etc.

So I am guessing Q6002 is fried?

[shaker31280]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Sorry 0 meaning its closed.

[rievax_60]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Sorry 0 meaning its closed.

Are you using the resistance range or diode test range?
Pins 1,2,3 are usually the Source. Pin 4 is Gate. Pins 5,6,7,8 are the Drain.
Look at this to know how to properly identify the pins,

[fddizon]

Re: Toshiba Satellite C655 won't run off AC. Need schem.

Testing Q6002, if I am doing this correctly. It has 8 legs, 4 on each side.

For number purposes I show the leg numbers below.

1 2
3 4
5 6
7 8

If I use a multimeter and check for resistence between 1-2 I get 0, 3-4 I get 0, 5-6 I get 0, 7-8 I get 0. 0 being its opened.

If I check Q6003 the same way I get some resistence, the meter goes from 1 to .102, .09, etc.

So I am guessing Q6002 is fried?

you should test in this way bro.

pin 123-5678 - should read resistance in one way only. (pins 123 are connected with each other and pins 5678 are connected with each other too) so you can choose any pin from each set to test. if it reads both ways, remove it from mobo and re-test.

hope this helps.