Thread: reversed polarity == Kentucky Fried Lilliput?

Originally Posted by hud

please say it isn't so...

I hook my Lilliput up directly to my car computer's PSU, via one of the internal molex connectors. well, when I wnet to hook my car PC back up to my Lilliput the other day, the two power wires to the Lilliput had fallen out of the Molex connector. So, not even questioning it, I put the two power wires back into the molex connector, because I thought I knew which wire was which. Well, apparently I got them reversed, and I powered off once I quickly realized my mistake. After swapping the power wires back to the correct arrangement, well, now my Lilliput power light still turns on, and pushing the power button on the lilliput will turn the power light from red to green. However, All I see on the display are some whitish-grayish horizontal "bands" wavering across the top half of the display. That's all I get on the display.

So, am I screwed, did I completely trash my $250 display? or is there hope, is there any fuses or sacrificial diodes or anything like that inside my lilliput that might have limited the damage?


Please help...

You got to open it. Look at the boards, and see if you see anything marked as an "F" somethine, like "F1", "F22", and then check it for continuity. If no continuity, then replace.

Also, check for anything burnt looking on the boards. Did you hear or smell anything. If not, then it may not be a big deal.

ALso, check all the cables to make sure that they did not fry or melt. THey will be easy to recognize.

There are several different boards in a monitor, power, inverter, and VGA. Sounds like you might have an issue with the VGA baord, though since it connects to the other boards, the problem could be anywhere.

Perhaps someone with more Lilli experience will chime in.

If you don't know what a continuity test is, the read up, or take it to a professional. If you don't have a tester, the same thing applies.

Michael

Originally Posted by hud

Michael, thanks for the quick and helpful response. I did open the unit, and looked for burnt/melted stuff, couldn't find anything really. Everything looked pretty normal to me, but I'm no expert. Ok, F1, F22, continuity check, eh? I'll read up on that and try it. Thanks again.

-hud

No problem. the "F" designation, which is silkscreened onto the circuit board near the individual component is an indication of the type of component, in the is case, a fuse. There are many others, R for resister, C for capacitor, D for diode, etc. You obviously want to check for fuses, though truthfully, anything can go with reverse voltage, but that is probably beyond your ability to diagnose. I think it is beyond mine as well.

Continuity is just a check to see if the fuse has "blown" If the fuse conducts, then it is fine, if it doesn't conduct, then it is "blown". You need a continuity tester, they are cheap, or you can build one yourself easily, but it aint worth the effort when a tester is about 15 bucks. It aint a good one, but it will do for your needs.

Hopefully it will be an easy fix.

Michael

This is one of the thread but you can also search for Lilliput + fuse
So it finally happened to me.

Originally Posted by MatrixPC

This is one of the thread but you can also search for Lilliput + fuse
So it finally happened to me.

Good find, but I think that he gets lights, and flickering, so it might be the cable issue mentioned, though checking that fuse would be a great start. The picture is at the end of the thread.

Michael

Originally Posted by Wiredwrx

You got to open it. Look at the boards, and see if you see anything marked as an "F" somethine, like "F1", "F22", and then check it for continuity. If no continuity, then replace.

Michael

Thanks heaps. I would not have picked that to be a fuse. but looking at it now i nutted it out i c what they do. the diode allow current to basicly short circuit back to earth preventing damage to any other components and the fuse blows straight away due to the current drain. pretty clever i admit, but if you didn't say what you did i would never have picked it as a fuse. so thanks heaps.

SOBIL