Failed screen replacement, now system won't power on

[sn00p]

hi,
I was given a X60s with a broken screen, I purchased a replacement "compatible" screen off ebay & attempted to install it this evening.

The X60s cam with a LTN121XJ-L07 Samsung panel, the replacement panel is a LTN121XJ-L03, I gave the seller a benefit of the doubt and assumed it was the correct panel.

I swapped out the panels, the new panel is slightly off size on the top, apart from that all was well. Switched on the laptop to see if it worked & as the fan & hdd spin up, the system switches off & won't do anything else with whatever I try.

The motherboard appears to be alive (removed RAM & it beeps in sequence)
LED's on inverter board light up & change sequence (one iteration)
Same behaviour if I install old broken panel now.
Remove wifi & disconnected display ribbon without any difference.

Any pointers?

[ajkula66]

Welcome to the forum.

Your "new" panel has most likely blown a fuse on the motherboard.

If you're handy with multimer and a soldering iron you can find it on the board - it will have an "open" reading - and solder another one piggy-back style over it.

Having said that, with a machine that is worth maybe 50-60 quid on a good day, I wouldn't even bother.

Return the screen, get your money back, junk the rest and move on.

Good luck.

[sn00p]

If you're handy with multimer and a soldering iron you can find it on the board - it will have an "open" reading - and solder another one piggy-back style over it.

I'll try & get a look tomorrow if I can

[ajkula66]

I'll try & get a look tomorrow if I can

Do bear in mind that these fuses are *tiny* and were not meant to be user-replaceable. However, I don't see that you've got much - if anything - to lose at this point in the game.

Good luck.

[sn00p]

thanks, I'll report back once I've had a poke around

[RealBlackStuff]

There's a post "X60 fuselist" at the top of the post-list.

[sn00p]

noticed that, very handy, just hope the fuses are available

[sn00p]

Seems like fuse F5 based on using the tone test on a multimeter to indicate a circuit, all other fuses generate a beep either way the probes are attached, F5 results in silence. Is this valid?

[RealBlackStuff]

F5 is one of the display fuses, so yes, it's the most likely candidate.
Get 2 or 3 when you buy the fuse, just in case.

[sn00p]

so I've stripped the system bare to test with the multimeter & now that I've put it back together & tightened the screws (minus ribbon & display), the system now stays on & appears to be running.

Does the system go into any failure mode if it detects an incompatible part where it refuses to POST or some such behaviour?

[RealBlackStuff]

A non-working screen (because a fuse is 'gone') won't stop the rest from working.
Hook up an external monitor, see if that still goes.

[sn00p]

the issue I'm trying to diagnose is the system not remaining on, I brought the computer back home & tried to power it back on again & it's exhibiting the same behaviour again, switch on, fan spin, hdd begins to spin up & then the system switches off.
there's no monitor connect or lcd panel.
when it oddly began remaining on, I did connect an external monitor & it was running fine.

[Billaboard]

If you do check the fuses, I'd be very interested to hear how you get on. Here, I've made up some probes by soldering wires to the top of a couple of sewing needles, then moulding a plastic disk across the top (using red and black "sugru") to give me some area to apply finger pressure. The wires then go to a "chocolate-block" into which I can poke the regular meter probes.

I haven't yet had the time and been sufficiently relaxed to try it out.

Not sure if people in other countries will know what I'm talking about, but someone from London should!

[sn00p]

I just used the probes from the meter on the fuses. I didn't check the values of the fuses, just made sure there is continuity in the circuit (audible tone from the meter).

Update:
worked out why the system would occasionally start normally, external VGA being chosen as the primary display when the system completed POST I pressed Fn-F7 to switch displays & the system switched off immediately, then the system began switching off again on subsequent power attempts.

[axur-delmeria]

Remove CMOS battery to revert to default settings --> external VGA primary output.

I pressed Fn-F7 to switch displays & the system switched off immediately,

Was the LCD cable attached when you did this?

[sn00p]

Was the LCD cable attached when you did this?

Yes, LCD ribbon & inverter attached

[axur-delmeria]

Was an LCD panel attached as well?

If yes, was it the old one or the replacement?

[sn00p]

No panel attached, any tests now happen with the old cracked LCD panel

[axur-delmeria]

The pinout of the LTN121XJ-L03 is different from L07 especially these:

Pin # - L03 / L07

Pin 1 - 3.3v / GND (!!)
Pin 2 - 3.3v / 3.3v
Pin 3 - GND / 3.3v (!!)
Pin 4 - GND / VESA DDC 3.3v (!!)

If you plug in L03, it will short 3.3v to ground in 3 different pins. :O

LTN121XJ-L03 datasheet http://www.distrib-informatique.com/lcd ... XJ-L03.pdf

LTN121XJ-L07 datasheet http://www.beyondinfinite.com/lcd/Libra ... XJ-L07.pdf

What happens when you plug in the cracked panel?? Does the laptop still boot properly?

[sn00p]

fuse is blown, nothing gets shown on the broken LCD, if you can get it to boot with external monitor as primary display, system remains on, otherwise it switches off after a couple of seconds, waiting on the F5 fuses to show up, will be soldering them on later next week. hopefully system will remain on then & the system will be back to before I started with the incorrect display.
It's then waiting for the seller to sort out the replacement LCD.

[sn00p]

replacing fuse f5 fixed the problem. system is back up & running again, I can switch between lcd & external monitor without the system switching off.
Now need to source a replacement screen again.