Re: Dell E172fpb

I'm happy to report my E172fpb is working again! I'm very sure SellDoor's advice about resoldering the board did the trick. I did get the other electrolytic caps on the PS board replaced. I decided to not replace the caps on the digital board.

BUT, I'm somewhat embarrassed to report I was not careful about mounting the two 5707's located towards the edge of the PC board and one or both collector tabs we touching the case causing an overload. They were sitting too high; I was thinking it would help the airflow. I'm lucky they didn't short out!! ...

Re: Dell E172fpb

Here's the link to the Benq schematic; I think it bears a very close resemblance to what I've got:
[URL="https://www.badcaps.net/forum/showthread.php?t=4304&highlight=benq+17&page=15"]https://www.badcaps.net/forum/showthread.php?t=4304&highlight=benq+17&page=15[/URL]
It's attached to Post #299

Also, thanks for not asking for good close-ups of the board. I can get them to this forum soon!Re: Dell E172fpb

Here's the link to the Benq schematic; I think it bears a very close resemblance to what I've

Re: Dell E172fpb

I have checked them in-circuit with my DMM set to diode mode. I'm comparing my readings with the matching pair.
You make a good point about resoldering. I ordered some additional Solder-Wick with my caps from Digi-Key. I will take your advice!
One other observation I'd like to relay from a little earlier in the troubleshooting phase was that I removed the pico fuse to see if the +5 and +3.3 supplies would stabilize. With the inverter circuitry connected and the power button flashing on/off I measured fluctuations on +5 and +3.3 that followed the flashing....

Re: Dell E172fpb

Thanks again SellDoor,
You are right, life is too short! But, I have gone over this thread as well as a similar Benq 17" thread. There I located a good schematic of the ps/inverter board. But, I have yet to go over re-soldering the board. I've been over it with magnifying glasses and the solder side "looks" OK. But it won't hurt retouching it a bit. Also, I've decided to go ahead and get the rest of the electrolytic caps changed. Let's see how it goes!

Re: Dell E172fpb



Thanks for the tip! It made me re-think the situation and try more troubleshooting. Now that the CCFLs are out of the case, bench-testing is easier to see what's really happening. Only one set of lamps tries to fire; but exchanging them between connectors on the inverter/ps board, both try to fire. I should say here I'm back to the Power Button flashing mode. Connector CN753 which would connect to the lower CCFL is not producing HV.

So, back to the drawing board and try to figure out why that section is causing an overload shutdown....

Re: Dell E172fpb

Hello All,
I'm new to this forum. I joined a couple of weeks ago to better understand what it might take to repair a Dell e172fpb I'm trying to save from the landfill.

It started out as a 2 Seconds To Black problem that was traced to a couple of '5707s being shorted. After getting a transistor/fet/fuse repair kit from eBay it then started doing the Power Light Flashing mode, so I got a replacement cap kit from eBay. Really there was only one obvious cap failure, one of the 1000mf @ 10V ones...but what the heck put them all in.

...