Satellite c660d help

[ala_borbe]

hi all

i have toshiba C660D-13V
PSC20E-009001Y4

its left for me to repair for myself
its said that it was dropped and it gives no image

i reflowed it, flashed the bios and now symptops are strange


when i press power button, fan spins, caps lock responds, num lock responds, but still no image (no back light, no image)
no image on external VGA connector
when i press power button briefly it tuns off like normal

when i take RAM out, it turns on, caps lock and num lock DOES NOT respond, it wont turn off unless i pres and hold power button for a few seconds


any ides? ati chip i suspect but i need your point of view

tnx in advanced

[atsio]

Re: Satellite c660d help

Dropped laptops, the worst case. I have even saw broken lines on memory slots of dropped laptops. I suggest an "oven" reflow of the board (190 to 200 degrees)

[bicalov]

Re: Satellite c660d help

for how long?

[atsio]

Re: Satellite c660d help

190 το 200 degrees is not dangerous for the most parts on the board so time is not an issue. You just need to cover plastic parts and any aluminium smd capacitors with aluminium tape. Of course you need to monitor the temp on the board with thermocouples.

[bicalov]

Re: Satellite c660d help

THx

[sparker1]

Re: Satellite c660d help

Maybe remove cmos battery first

[ala_borbe]

Re: Satellite c660d help

oven is my last option... avoid that as much as possible

i tried another cmos bat... also tried to look for LID switch but i could not find any...

[dj_ricoh]

Re: Satellite c660d help

Got a scope?

[ala_borbe]

Re: Satellite c660d help

nope sry, no scope

[atsio]

Re: Satellite c660d help

oven is my last option... avoid that as much as possible

i tried another cmos bat... also tried to look for LID switch but i could not find any...

Why? What is the difference when you put it on the BGA station and preheat it to say 190-200 degrees? The difference and actually the problem is that with the most preheaters temperature is not even all over the board due to size. If the preheater is big one for the board and you bring up the temperature slowly so as more dense parts of the board to catch up with the temperature is the same.

[dj_ricoh]

Re: Satellite c660d help

nope sry, no scope

Can you post a picture of the board?
I wanna see the layout.

[ala_borbe]

Re: Satellite c660d help

hey i made breakthrough... i got myself another c660d with smashed screen, only half of screen was visible, other side smashed

i put my screen on this one (my screen had no trace of damage) and it gave image for shot time, 5 sec, but color was green instead of white, and then goes black

so i put back smashed screen back and now its this one is dark too... but it was not before

so my LCD destoyed LVDS fuse??? lould it be so? can you help mi find lvds fuse/diode?
i tried before LCD cable before so that may not be the cultprit

[Djosla]

Re: Satellite c660d help

Ala_borbe you should check L45 inductor...it is backlight rail...
Also check L12 which supply lcd... both on page 17 of schematic...

[ala_borbe]

Re: Satellite c660d help

board has only some markings, but i have no boardview

l45 mesures ok, when on it has voltage on both ends
could not find l12

lcd connector pin 22 and 24 0v (+LCD_VDD)... traced back to q33 which has 3.3v on 2,3 pins, rest pins 0v... suspicious

[Djosla]

Re: Satellite c660d help

If you have voltage on l45 than backlight power is ok...
q33 should be dual transistor...can you take a good image of that area??
You should check UMA_ENVDD signal?
And what voltages do you have on pins 10,12,22,24 of lvds connector ?

[ala_borbe]

Re: Satellite c660d help

its not back light problem i tried illuminating with flashlight
pic can be there tomorrow
q33 measure like this

2,3 pins have 3.2v rest 0v

so no UMA_ENVDD signal

LVDS when board on
10-2.3v
12-0v
22-3.3v
24-0v

[Djosla]

Re: Satellite c660d help

LVDS when board on
10-2.3v
12-0v
22-3.3v
24-0v

Did you check this correctly? 22 and 24 pin should have same voltage and 0v i belive...they are connected...

Now remove q33 transistor...(don`t throw it out ) and put jumper from pin 2 to pin 6(pin 6 is connected to L12 inductor so you can connect there if you are not sure)...we do this to power screen directly...

Now BKOFF#_R=0v is problem... Carefully pull out pin number 12 from lvds cable connector(in order to be disconected from motherboard) and than connect it to same L12 inductor...Just bind it ,dont solder it because you will destroy pin...Try to turn on laptop and post results ...

If cpu is ok you have problems with kbc most likely...
Do you get image on external with lcd cable detached from laptop?

[ala_borbe]

Re: Satellite c660d help

first of all, thank you for your help

ok, let me recheck and correct this...

all test done without display cable, hence display not plugged in

i have got image on external monitor

pins
10-3v
12-0v
22-0v
24-0v

this is correct, yesterday i got something wrong, maybe missed a pin

q33 confirmed, only pins 2 and 3 have 3.2v

taken q33 out, shorted pins 2 and 6

now pins 22 and 24 have 3.2v

part with pin 12 sounds scary ... not sure i understand it correctly
can i use thin wire (one wire form PATA hdd cable.... it should melt in case of high current, right...?) to short pins


edit:
it seem you are right about kbc (ene kb926qf) pin 105 BKOFF# in 0v...

[Djosla]

Re: Satellite c660d help

ok that`s good now...
pin 2 and in 6 connected thats ok...you should now have image on screen but no backlight...

BKOFF# should be 3.3v...it is just backlight enable,it doesnt need thick wire...backlight power is over l45 inductor...

In order to BKOFF# has voltage you should take 3.3v from inductor l12 (or pins 2 or 3 from place where q33 used to be) and connect it to BKOFF# pin...but you can not connect it directly to motherboard pin of lvds connector because you would connect same voltage to kbc and possibly damage something...That`s why you need to pull out single pin 12 from lcd cable connector and connect it to L12... In this way BKOFF#=3.3v goes only to lcd panel not to kbc...
Probaj pa javljaj kolega ...srecno....

[ala_borbe]

Re: Satellite c660d help

first, thank you for your kind help, you are my hero
second, it took me a while to get proper working screen to continue...

connecting new display did not help... no image
so i got myself KB926Q... replaced it, put back Q33 and turn on
now i have image but no back-light... so back to measure
could not find L12, no markings on board

but now pin 10 on lvds is 0v... wtf
could this kbc be also dead? i can get another

ako ikad budes prolazio ili dolazio u bosnu svrati obavezno na cugu na moj racun