Acer 2920Z Inverter Problem (pics inside).

Hi.

I have an Acer 2920Z alptop with an 12.1 inch LCD screen. The problem is that I did not have an inverter so I bought a new one. It arrived today.

I installed and nothing happened... So after a second look I found that my VGA cable (from mobo to inverter) had 2 wires lose in the inverter connector (blue and black cables), you can see it on image1, and now I do not know which one goes in which pin as the broke in the very tip.

Can anyone help me to identify where does the 2 cables go? It is a 6 pin inverter (image3).

Y soldered the cables the the broken pins (image2) but I still don't connect it as I do not want to blow anything (I can swith the, no problem).

Also, how do I test if my inverter is getting VOLTAGE from the MOBO? Which cables are the test point?

The problem is not from my LCD as I tested with a different inverter o another laptop and It turned the CCFL on.

UPDATE!!!!

Before connecting anything, using a multimeter I measure every cable that goes from VGA to Inverter... supossedly they are 2x19V 2x3V and 2 Ground (?)... I think I have the 2x3V and 2 Ground but no 19V --> this powers INVERTER.

So, I had to dissassmble the hole laptop.

As you can see on image4 adn image5, near the LCD Connector the are 2 Fuses (F1 and F2). After checking both sides of F2, both gave me 3V constat (when PC Turned ON).

But F1 gave me 19V on one side (the opposite to LCD conn) and 0V on the other one... that leads me to beleive that this FUSE is blown...

So how do I check this? Is there any logic in what I say? Actually If you see the traces of the F1 they go from power supply to LCD1 conn...

Maybe I had cutted cables and blown fuse.

Bye.

PD: The inverter is a YNV - W05.

 

The fuse is definitely blown if there is voltage on one side and not the other. Also if you measure it on "ohms" on your meter it should read 0.00

Be absolutely sure the meter leads connect OK as any laquer or flux can prevent connection and make you believe there is a problem. Fuse 1 is shown as 4 amps... that's enough to power the whole laptop ? I can't see fuse that being related to just the display.
19 volts is more like the main DC supply from the AC adapter.

Does the laptop appear to boot up OK... is it "just" a display problem ?

 

The only quick way to get the cables connected correctly is to ask someone else with this model to take a look (if you are very luck then the service manual may have a photo).

The blown fuse, if it is blown, clearly needs fixing but given the 5 - 6A that would have needed to flow to blow it you need to have a good look around for why or where the damage /fault is that made it blow first !

(And stating the obvious your bare wires on the plug at the moment are an accident waiting to happen)

 

Mooly: is voltage in one side and nothing in the other, measuring with ohm shows no continuity and the meter leads connect OK as I kind of lighlty "pinched" the soldering. I think it is related to the display because of what I show you on image6. The laptop works perfect If I use it with an external monitor... I think it is a display only fuse.

BruBoo looking the MP1010BEF (IC of the inverter) I found some info on the pin layout and it seems that first is black and next is blue (like in the picture). About the wires, I know... that was for the picture only, now they are correctly insulated.

Also... because in my country it is impossible to get on SMD-SMT supplies without getting 100+ o 1000+ I had to search on the net...

So I bought 10Pcs of Littlefuse 1206 32V 4AMP resistors on ebay, waiting them to arrive (a few weeks).

 

They should work fine (they are fuses not resistors of course).

I would advise a quick check by pressing one of the new ones on top of the old one to see if the new one blows too or the Backlight comes on. If all is well the aggravation of removing the old fuse and soldering the new one in place is then a better investment of time - you won't have endless chances to remove and resolder the component before the copper tracks on the board start to degrade and lift

You could do the same thing in advance of the ebay fuses arriving if you have a 3 or 4 amp micro car fuse you can bend a bit to bridge the fuse on the board. Not a permanent fix but will save you waiting if you actually need to be replacing something else instead . .

 

You will only know by trying. You can always tag (solder) a fuse across the blown one to see what happens.
It's very hard to give you definite advice advice without actually having it on the bench to work on.

If you measure on ohms and there is no continuity it is OC (Open circuit)

 

One other thought... you say you think it is just the invertor that is at fault... if so then the screen image will still be showing normally... if you shine a torch etc on the screen you should be able to make it out.

 

Mooly, that's correct... If I use a flashlight towards the LCD or from behind (when disassembled) I can see the images with no problem. It is just a CCFL problem or better said... a powerless inverter problem.

BruBoo, I tried with an old fuse (just for testing purposes as it is quite big) and I did got 19V on the other side towards the inverter... and It lit up! After that I quickly desolder everything waiting for the fuses to arrive as I do not what to blow anything because of my impatience.

 

Excellent news !

At least now you know the fuse will solve the problem . . . come on postman !!!

 

Thats great

 

can you give me inverter closed images from top, focusing on chipset and connector (where data cable from motherboard connect to).
or, give me chipset codes that used in this inverter.

i think, this inverter uses OZ9910 ...
then, if my assume is right, this is standard pin configuration for inverter that used this type of chipset.

for 6 pin connector,

• pin 1,2 connect to VCC (DC 19V)
• pin 3 used for enable signal from motherboard
• pin 4 used for adjust brightness level for ccfl tube
• pin 5,6 connect to GND

first, you should find right connection, between VCC and GND pin. If you found that pin 1 is VCC, then pin 6 (and 5) must be GND. find
otherwise, if pin 1 (and 2) is GND, then pin 6 (and 5) must be VCC.

next step, how to find right connection for enable signal???
this is very simple, don't worry ....
you must only locate where is pin that have 3V at normal operation.
then, connect it to pin 3 or 4 (try one by one)

can this step damaged your inverter??
no, because enable signal is 0-3V ... and brightness level is 0-5V
so (in my experience during this) is not damages for your inverter.
except if your take wrong connection between VCC and GND, fuse must blown


but, this configuration can be difference depend on inverter models.
that's why i need closed images, focusing on chipset and connector area

think free to send any question to my email, or maybe you can contact me over Yahoo Messenger at [email protected]

i still here to help any problem