Dead Lenovo Thinkpad Edge E520 (BIOS ?)

[atsio]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

I'm checking the other board and the four FETs at the BD95280MUV look suspicious, at least two show short and the other two show different reading then on the other board.
I would need some help, finding these FET transistors: S406 and PBNDT(seems like it is a Fairchild= F mark). I can't find anything. Size is 3mm x3mm(QFN8?).

You mean PU4101, PU4102, PU4104, PU4105?


You didn't answer about amps drawn. Is the board reboots continuously?

[tibimakai]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

Yes, those.
I don't have a schematic for this laptop.
Sorry about not checking the amps, I have forgot about that(did not re-read the thread). I will do that today.
It tuns on, fan spins for a bit, than stops and than it restarts with full speed. And it stays in this mode, until I turn it off.

[tibimakai]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

I have found these, in the E420 schematics(page #41), but I'm not sure, if they are the same in E520: PU4101/PU4102 ARE SIS412DN-T1-GE3 AND PU4104/PU4105 ARE SIS406DN-T1-GE3.

[tibimakai]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

Just to clarify things here.
I have two identical boards 04W0398, that I'm trying to repair, or at least one of them.
One seems completely dead, most likely has something shorted, to me it seams that the ) PU4101/PU4102 and PU4104/PU4105 pairs.
I have replaced the BD95280 IC already, it was shorted(I shorted it, by measuring a pin). Initially it was not working. I thought that is a bad EEPROM, so I have replaced it, which did not fix the problem.
Then, by mistake I have touched the probe between the BD's pin and a tall SMD cap(20V one), which blew the IC. Most likely there are more components shorted somewhere. Most likely the PU FETs.
Second board I have purchased to replace this one. I have not used my glasses, when I was plugging in the LVDS cable and I have broke the LVDS cable's connector and most likely I have shorted something. This is the board, that only the fan spins and the green LED is on, when the power adapter is plugged in. I can measure the 20V, 3.3V, 5V and the Vref 2.0V around the BD IC.

[tibimakai]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

I had a little bit time, to check out U4901.
At the Vin I have the 3.3V, but there is nothing at the other two pins, #1 and #3.
I have replaced this IC, from the other board and I have got the same result.
I have managed to brake one pin from the U4901, so the other board, that is dead, has to wait for a while, until I will get another IC. I won't be able to measure the current. I'm keep thinking, on how to measure it, without cutting the power cord(which I'm not willing to do).

[khaahk]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

You should create two different topics, it is hard to understand what is going on.
Does the board #2 show picture to external video output?

So - pin #1 is low (that is enable signal voltage for panel 3.3V supply), signal should come from PCH. You can connect pin #5 to pin #3 to test wheather it will show some results to panel, but i doubt it. Before measure if pin #3 to GND does not show very low resistance.
But most likely you have a dead PCH or EC on that board...

You have a lab power supply, but it does not show amps drawn?

[tibimakai]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

For now, I want to repair the one, that shows some life. The dead one, I will put it away for now.
I have a power supply, but I don't know where to connect the leads.
On the mobo, there are five solder joints at the power connector.
One of them shows 3.2V, which confuses me.
Should I just solder it, to one of the 20V and power it that way? I believe, this was meant to be done, for the dead board.
PCH is replaceable, or should I toss this board and start working on the other one?

[dlshad96]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

Hello Mates

i have white screen issues on this board E520 - with external monitor every think O.K but internal screen just white screen i change the cable and the LED screen same

problem any ideas please

Waiting for reply
thank you in advance

[dlshad96]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

You mean PU4101, PU4102, PU4104, PU4105?


You didn't answer about amps drawn. Is the board reboots continuously?

Hello Mates

i have white screen issues on this board E520 - with external monitor everything O.K but internal LCD screen just (white screen) i change the cable and the LED screen same problem .the LCD screen with another laptop works fine. !

any ideas please

Waiting for reply
thank you in advance

[dlshad96]

Re: Dead Lenovo Thinkpad Edge E520 (BIOS ?)

Any one have any ideas please.

[Adnankamboh]

Lenovo Think pad E520 Password Lock Bios . Plz UNLOCK This

[SMDFlea]

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