DeLL E152FPc Goes black after a second.
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From: propman on 9 Oct 2009 14:56 Jeff Liebermann wrote: > alternatives. Fortunately, I can type at about 30 mistakes per minute > without looking at the keyboard, so single vision is adequate for me. LOL! We must have had the same typing tutors!
From: PlainBill47 on 9 Oct 2009 15:35 On Thu, 08 Oct 2009 13:00:17 -0700, D Yuniskis <not.going.to.be(a)seen.com> wrote: >PlainBill47(a)yahoo.com wrote: > >> As a rule of thumb, when a monitor has a defective cap, I will replace >> the lot of them. As you point out, it's not worth the risk of having >> to open the monitor up again. >> >> I prefer Panasonic FM or FC series for replacements. Purchasing from >> Digikey, I can redo an entire monitor for under $10, including >> shipping. (OK, I seldom replace the 100 �F 450 Volt cap). > >I've only seen one of these "bad" (in about 100 monitors). >Despite the fact that they are often manufacture by the same >company who manufactures the other (crappy) caps on the >board! I guess the ripple currents are not as large (?) The large (rectified mains filter) is handling 120 Hz ripple (and the pulses from the SMPS). The filter caps on the secondary are handling 100 KHz or greater ripple. As I understand the problem, the ripple current will cause heating (duh!), which will cause the ESR to rise, causing more heating, until eventually a poorly made cap will vent. The mains filter cap has several advantages - much lower current and much more surface area to dissipate the heat. PlainBill
From: Samantha on 11 Oct 2009 18:10 Took the time today to open that monitor. It went pretty smoothly, found all the tabs with the help of a small spackle knife. Found the buldging 1000uf 16v capacitor. Found a replacement on an old board from a TV and swapped the two. I have the monitor on and the test pattern up now. Have let it set for about an hour now. Will leave it for a few more to make sure nothing else happens... Want to give you all a lot of thanks for the help. I probably would have stumbled around inside there for quite awhile before I really figured out how it work. Knowing how something breaks (common failures) is invaluable when trying to troubleshoot something. Thanks to all!! S.
From: Samantha on 11 Oct 2009 18:22 In article <4493aa23-cd53-4726-83e6-a7ac62a03820(a)p23g2000vbl.googlegroups.com>, Jake <mechanicaljake(a)gmail.com> wrote: > On Oct 6, 6:19�pm, Samantha <saman...(a)comcast.net> wrote: > > I have a Dell E152FPc Flat screen Monitor 15" that goes black after > > about a second after it is powered on. �The Green power light stays on > > and the color bar test pattern is there if you stick a flash light up to > > it. � > > > > I have never had one of these apart and am not really sure what I am in > > for. �Just looking at it, I don't see any obvious way to take it apart. > > > > There are some screws to take off the stand, but after that I am not > > sure. > > > > Anybody ever take one of these apart and fix it? > > > > Would greatly appreciate any help. > > > > Thanks so much!!! > > > > S. > > I recently repaired 3 E153FP's, which I believe are virtually > identical. > > The problem was a 1000uF, 16 volt capacitor, used for the power > supply. It had excessively high ESR, and I am assuming it caused > excessively high ripple voltage which was making the LCD's control > circuitry wack out (that's my very technical description of what I > thought was going on, ha ha). I replaced the same cap on all 3 - It > was easy to identify, about the largest cap on the board, the PCB > material was darkened around it, and the top of the cap was bulged. > > Good luck! The 3 I fixed had the exact same symptom you describe, and > have been back in service for about 3 months with no further problems. > > -Jake That is the same same with this one. Found a suitable replacement and done. Thanks!!
From: Jamie on 11 Oct 2009 20:06
Samantha wrote: > Took the time today to open that monitor. It went pretty smoothly, > found all the tabs with the help of a small spackle knife. Found the > buldging 1000uf 16v capacitor. Found a replacement on an old board from > a TV and swapped the two. I have the monitor on and the test pattern up > now. Have let it set for about an hour now. Will leave it for a few > more to make sure nothing else happens... > > Want to give you all a lot of thanks for the help. I probably would > have stumbled around inside there for quite awhile before I really > figured out how it work. > > Knowing how something breaks (common failures) is invaluable when trying > to troubleshoot something. > > Thanks to all!! > > S. Maybe you might already be aware of this ? but I'll spit it out in case some one else here may benefit from it. When ever replacing caps found bad like that, in inverter supplies, it's a good idea to make sure you use computer grade or some sort of low ESR types. This is one of the problems that plague these types of circuits and high ESR just pushing it along faster making the cap run warm. |