Re: 2007FPb turns off after 0-3 seconds

Well, we just had a dip... but it came right back. I guess I'll just "monitor" it(hehe) and see how frequently this happens and decide if its worth the effort to correct.

Edit: another one, within a few minutes.... looks like I declared it fixed too soon.

Tomorrow I'll get pictures of the logic board and hopefully you can help me pinpoint the regulator(s) and how to test them.

Re: 2007FPb turns off after 0-3 seconds

I was doing testing on it with all the boards connected, but with the panel disconnected. At first, I heard a whine every ~3-4 seconds, corresponding to the previously witnessed power off. Right before the whine, the voltage on the 3.3V secondary line would drop and then recover. The 19V (18.9V) stayed constant the whole time.

However, while I was testing, this behavior stopped. The 3.3V stayed constant. I tried to get it to repeat by unplugging from mains, draining the big cap, and replugging, but no avail.

On a...

Re: 2007FPb turns off after 0-3 seconds

Ok, I tried with a source attached, just in case, and it still exhibited the same symptoms. It doesn't look like a sleep mode power-off, it happens mid-startup.

I was thinking that R615 was shorted, but the resistor code(Br Gr Slv) says its .15 Ohms...

Hmm... since inductors probably don't have electrolytic fluid in the, you're probably right about the glue.

I'll post pictures of the other boards, too. I guess since there's a steady ~20V, it might not be the power supply...

Not sure if this...

Re: 2007FPb turns off after 0-3 seconds

I snapped pictures of the front and back of the power supply board. When I listen closely, I do hear a small clicking at approximately 10Hz. The output line is holding steady at 18.9V.

No signal is applied.

Looking closer at the board, several inductors (L610, L612, and L701) do appear to be leaking......

I picked up a Dell 2007FPb from the trash pile at work with the sticky note "BAD; power fails"

I opened it up and noticed it had a blown fuse. I replaced the fuse, and now it powers on and the LCD displays the Dell startup splash. The backlight works, so the inverter appears to be ok. However, after a seemingly random time (longest I saw was ~3 seconds), it turns off; not just the screen, the power/status LEDs as well.

I visually inspected the power supply board and there don't appear to be any bad capacitors or other components (although I suspect that...