Sony Vaio VPC-SB26FG cannot power on

[gisbern]

Re: Sony Vaio VPC-SB26FG cannot power on

Anybody find the solution? Now im also in the same situation, Capacitors near the small 6-pin connector are all shorted, so there is problem somewhere with shorted component. Capacitor? semiconductor ?. Please if somebody find the fix, let us know on this post. Thanks to everybody

[guruji]

Re: Sony Vaio VPC-SB26FG cannot power on

Hello,
I have the same problem what i understand they have 2 supply dcbatout and the other is vcc charger r for main mosfet to supply the mosfets i have not started with the laptop repair in full swing but will get my hands on it does anyone want the dockin schem ill email it thanks

[gisbern]

Re: Sony Vaio VPC-SB26FG cannot power on

Hello,
I have the same problem what i understand they have 2 supply dcbatout and the other is vcc charger r for main mosfet to supply the mosfets i have not started with the laptop repair in full swing but will get my hands on it does anyone want the dockin schem ill email it thanks

Please send it to this forum to everybody. I found another post https://www.badcaps.net/forum/showth...hlight=mbx-237 with simmilar dead problem. Im working on it may be also SN0608098RHBR problem... i will desolder it to check short problem.

My short problem is, that both power conector going from docking module - 6pin and 10 pin are shorted. so i cannot measure anything.

[Francisco.s]

Re: Sony Vaio VPC-SB26FG cannot power on

does anyone want the dockin schem ill email it

Why don't upload it to the forum?

[guruji]

Re: Sony Vaio VPC-SB26FG cannot power on

Ok today fixed the comp same model there are 2 signal to be checked one is the dcbatout =19v and the other bq24725_vcc =19volts there was a short cap near the sn608098 dc -dc by the way i did not see any 5v and 3.3v std voltage they get triggered after pwr_sw. But 3.3v ec is present.tomo i put up the voltage chart of the dockin board so it is easy for u guys to check

[ktokolwiek2]

Re: Sony Vaio VPC-SB26FG cannot power on

Good stuff! Can you please specify which cap is it, so I can check it on my boards?

[alihomee]

Re: Sony Vaio VPC-SB26FG cannot power on

its may be around cpu or near to power controller ic try to trace it unfortunately i forgot the location.............only small one or two components

[guruji]

Re: Sony Vaio VPC-SB26FG cannot power on

Can you give some voltage reading on dockin board like pq81 and pq82. And chargin ic supplies.would be easier to assist u

[chat007]

Re: Sony Vaio VPC-SB26FG cannot power on

I swapped the motherboard and it's now working . Thanks for pointing out the problem is on the MB. When you are swapping the board, make sure the dip switches match.

[chat007]

Re: Sony Vaio VPC-SB26FG cannot power on

Does anyone know how to change model/serial number in BIOS? Like a DMI tool?

[derattes]

Re: Sony Vaio VPC-SB26FG cannot power on

Hi guys! Have 2 motherboards with same problem... I found that r460 mosfet near SN0608098RHBR is dead. I have just ordered one from ebay, ref. SIR460DP-T1-GE3 . I will post results soon. By the way, anyone has schematics for the power board(cnx458) or have any experience with that? one of mine is dead too.

[jtamad44]

Re: Sony Vaio VPC-SB26FG cannot power on

how did you know the mosfet is dead, did u test it out of the board?

[derattes]

Re: Sony Vaio VPC-SB26FG cannot power on

Hi Guys, unfort. it wasnt just the mosfet, I get some readings now from the new mosfet but still not powering on . I'm not sure if the power board is fully working.I have 0.5v from the powerboard 6 pins connector(connected to motherboard) Does anyone has the schematics for the powerboard cnx458 ?

[michaeleangelo]

Re: Sony Vaio VPC-SB26FG cannot power on

Hi guys!
I have just registered to share a bit of my experience with this mobo.
I had no power at all on this laptop (current draw was 0.01A when connecting the power adapter to the laptop). BTW, I am using a very convenient chinese cheap power meter to see what happens to the laptops when I connect them: http://www.ebay.com/itm/261219652805 .

I had the black connectors (in yellow rectangles) on the mobo shorted with each other and to the ground. Therefore, the power daughter board MBX-458 did not provide 19V to the shorted circuit.

Then I soldered regulated power supply terminals to the points shown GREEN. The voltage was set to 1.5V, the current to 3A. The capacitor in a RED rectangle became hot immediately. So, it was shorted to the ground. After I have removed it, all the shorts with black (6-pin and 10-pin) connectors went away. The cap was replaced by a compatible 10uF/25V ceramic cap, and laptop turned on, was assembled and passed to the customer.

Of course, in your case this can be ANY other cap or semiconductor, but the main method is the same: apply safe voltage (lower than the intended voltage for the shorted circuit) to the shorted circuit and slowly raise the current while controlling the temperature of the board (with your hands or using any pyrometer).

Good luck, colleagues, and successful repairs to you all! :-)

[Francisco.s]

Re: Sony Vaio VPC-SB26FG cannot power on

I had the black connectors (in yellow rectangles) on the mobo shorted with each other and to the ground. Therefore, the power daughter board MBX-458 did not provide 19V to the shorted circuit.

Then I soldered regulated power supply terminals to the points shown GREEN. The voltage was set to 1.5V, the current to 3A. The capacitor in a RED rectangle became hot immediately. So, it was shorted to the ground. After I have removed it, all the shorts with black (6-pin and 10-pin) connectors went away. The cap was replaced by a compatible 10uF/25V ceramic cap, and laptop turned on, was assembled and passed to the customer.

Thanks for your very good explanations. I think it will help lots of people in the forum.

[gisbern]

Re: Sony Vaio VPC-SB26FG cannot power on

Hi all. I didnt find bad caps on my mobo, so i bought newone mbx-237. It seems to be ok, both black connectors are NOT shorted. When i connect, i can measure 19V with no prob. Unfortunatelly, system wont boot. When i press power, i can see cdrom short start (about 1sec) but imediatelly stop. No green light. But system is charging battery (one lucky point I can still measure 19v after it. May be BIOS is wrong. I have VPCSB, and bought mobo for VPCSA fyzically are motherboards identical, also both is MBX-237. Anybody has hint how to flash bios offlline? Thank you !

[Francisco.s]

Re: Sony Vaio VPC-SB26FG cannot power on

Anybody has hint how to flash bios offlline? Thank you

You need a external programmer. If you don`t want to buy a commercial one, you can search de web for one to be made by yourself, very easy and low cost.
Of course you need also de dump file of the bios.

[djromann]

Re: Sony Vaio VPC-SB26FG cannot power on

Hi guys!


Then I soldered regulated power supply terminals to the points shown GREEN. The voltage was set to 1.5V, the current to 3A. The capacitor in a RED rectangle became hot immediately. So, it was shorted to the ground. After I have removed it, all the shorts with black (6-pin and 10-pin) connectors went away. The cap was replaced by a compatible 10uF/25V ceramic cap, and laptop turned on, was assembled and passed to the customer.

Hi all! I've got the same problem with the same model of Sony. However, 90% of dead Sony I get in service all of them have the same problem- one ceramic capacitor shortened, usually near the CPU but in this case it's the same cap shortened as in michaeleangelo's case. The work methode is very right, but I prefer to check out the circuits, the caps with the multimeter only. In some difficult cases I use a infrared thermometer to find the chip/ element that is defect, sometimes it doesn't get hot- could have two degrees above the motherboard and checking with fingers you can't feel the right temperature.

[gisbern]

Re: Sony Vaio VPC-SB26FG cannot power on

OK ! My MBX-238 - THE SAME shorted capacitor ! Thank you for hint. Now both power connectors are NOT shorted anymore. Unfortunatelly, its still doesnt power on. When i plug both black connectors to mobo i can measure 19v. But just when i plug DATA BUS connector (beside both power connectors) i lost 19v imediatelly and system not power on. What is wrong ? Thank you for help.

(just for info, im testing that mobo WITHOUT shorted capacitor as i have no spare for exchange, but i hope its not my source of problem)

[vaiohustler]

Re: Sony Vaio VPC-SB26FG cannot power on

hi all hope are very well tell them that I recently bought this laptop second hand worked well but I can not turn on

searching the internet reaches the conclusion that it was the same failure cnx-458 series and vpcsb vpcsa as discussed here

the problem is that I have not been able to find out which component is failing and I was wondering if you could guide me a little to find the faulty component these are the readings I get

in advance thank you very much have a great forum