Help troubleshooting Dell laptop

[bassmen999]

I need help! I'm stumped. I have a Dell Inspirion 5150 I'm repairing. At first diagnosis, I thought the power jack was bad on the laptop since that is usually the case so I replaced the power jack but still no luck.

You plug the power adapter in to the power jack and I get NOTHING at all. I have tested the power adapter and its putting out the right 19.5 Volts. What else could it be?

Before I replaced the power jack, it was doing the same, dead. HELP!!

[willawake]

Re: Help troubleshooting Dell laptop

wow that model is a turd, posts are burning up the dell boards.
http://forums.us.dell.com/supportfor...cending&page=1

http://www.aqstech.com/5150pj.html

apparently excessive heat eventually damages the mobo. might be a solution here http://p068.ezboard.com/bi5150users but their hosting sucks today.

[bassmen999]

Re: Help troubleshooting Dell laptop

Thank you very much! I'm going to do some more testing on the board to find the culprit.

[bassmen999]

Re: Help troubleshooting Dell laptop

Hey everyone, here is a update. I took the thing apart and on the bottom side of the motherboard, less than a 1/2 inch from the power jack, I found this:





Does something look bad to you?

- Chad

[willawake]

Re: Help troubleshooting Dell laptop

can you do some more pics of other areas, also some not so close.

i think it is a zener diode but i am not sure

[willawake]

Re: Help troubleshooting Dell laptop

check this one also

The chip I believe its LCV14 and is located under the compartment labeled "c" it has 14 connections.

[arneson]

Re: Help troubleshooting Dell laptop

I would have guessed main board fuse. Very common to go out for lots of reasons.

[kc8adu]

Re: Help troubleshooting Dell laptop

looks like a spill victim.try some alcohol and a toothbrush.there is likely more elsewhere.
i see lots of notebooks with spills.mostly cola and coffee.can be fun to clean fine pitch smt and bga.
and you need a very fine iron to resolder the lcv14.
i use a wahl isotip with the 1/64th tip.

[bassmen999]

Re: Help troubleshooting Dell laptop

Here are some more pics as you asked:







Willawake: If its a diode then that explains the power issues. But it fooled me because it has color bands like a resistor. Hopefully these pics will help more.

arneson: Thats what I was thinking. Whats my next step?

kc8adu: How could I have a cola/coffee spill on the bottom of the motherboard?

[arneson]

Re: Help troubleshooting Dell laptop

Simple continuity testing.
Very small resister style fuses have color bands denoting amperage rating.
My last dead inverter board had one, it was open.

[bassmen999]

Re: Help troubleshooting Dell laptop

Ahhhhhhh! Well that makes sense! I'm gonna test it first thing tomorrow! Plus, where can I find a new one? Most likely place? Radio Shack possibly?

[willawake]

Re: Help troubleshooting Dell laptop

i still think its a zener diode in sod-80 LLDS package. so bear that in mind with your testing. the PZD6 designation on the board is an indication. you can google testing for that.

if the board is damaged by heat then we would be looking for partly desoldered components. check it all over, especially for legs of chips.

[arneson]

Re: Help troubleshooting Dell laptop

Yes I see that zd designation Will, so right on as a zener.
Very possibly in the power turn on area.

[bassmen999]

Re: Help troubleshooting Dell laptop

Ok, so its a zener diode. Now what replacement part am I exactly looking for? Such as rating and such?

[willawake]

Re: Help troubleshooting Dell laptop

just because it looks strange doesnt necessarily mean that it is a defect. if it tests bad then ok replace it but i dont know if anyone can assist to tell you the rating of that part. maybe you find similar on another board.

have you checked other parts of the board for disconnected solder points yet?

[bassmen999]

Re: Help troubleshooting Dell laptop

Well, ran some test on the board. I dont think its bad. Did a diode test and I got back this:



What do you make of this?

I checked the rest of the board. Didnt see any disconnected solder points. I'm going to keep checking I guess.

[arneson]

Re: Help troubleshooting Dell laptop

Did you locate the main board fuse? Always a prime suspect.

[bassmen999]

Re: Help troubleshooting Dell laptop

Havent located it yet. Tell you the truth, not sure what I'm looking for. I'm new to circuitry.

[arneson]

Re: Help troubleshooting Dell laptop

It's probably marked as "F" something and may look like nothing else on the board.
One on my satellite is small green rectangle. Other laps will use the longer round device with metal strap in the middle.
The location is the obvious give away, right near the power.

[arneson]

Re: Help troubleshooting Dell laptop

When I find them open, as I do on many dead laptops, I do a quick scan for tha cause,
burn mark on chip, bent pcm cia pins, shatered usb port, etc.
Wnen I'm satisfied I just apply power and short the open fuse with anything handy.
If she lights up, viola, replace fuse, usually 5 amp or so and reassemble.