The funny smell is usually from electrolyte leaking from bad capacitors. They were Abit ones affected by the so-called Capacitor Plague: http://en.wikipedia.org/wiki/Capacitor_plague There was an interesting industrial espionage story behind that where a Taiwanese was using an electrolyte formulation that was only partially recreated from a Japanese manufacturer. Continuing capacitor problems might be from that same formula still bouncing around, or they might be plain old heat problems, or simple under-engineering. On Fri, 2012-01-06 at 17:33 -0500, E Johnson wrote:
Dave,
Very glad to know that you managed to resurrect this thing. Meanwhile I am very happy with the new one.
Thanks for the feedback on how you repaired this unit. Its twin here (not in warranty) is still running fine, but I can imagine I someday might have to deal with a similar problem in this one. I used to build & instect & troubleshoot small electronic devices, mainly little telemetry units for rockets, & mysterious black boxes for aircraft carriers. Except now I have no soldering tools any more.
Anyway, mybe the dysfunctional heat sink was what caused the heat problem & early demise of the monitor. I now recall a "funny" smell right after the first blackout.
Hopefully the heat sink on the remaining one here is glued on well enough. If the DH ever turns loose of Monitor 2 long enough, maybe we can take a look.
Dave - How much disassembly is required before the heat sink is visible?
Thanks again to everyone here.
Liz J
On 6 January 2012 15:55, David P. Connell <davec99@charter.net> wrote:
Just for general info: the aforementioned Acer monitor from Liz had several obviously bad caps in the power supply section. They were all from the same manufacturer and the worst were all the same value. As mentioned below, I just replaced all of them while I had it open - well, not the very largest, or the very smallest, nor the solid ones. The big and small ones looked pretty good, with no signs of bulging or leakage and I'm hoping they were made on a different assembly line, since the values were way different from the bad ones.
It has been running for about 18 hours, played a full DVD movie, and returns from powers-saving mode. I'm not entirely convinced that one of the IC's is not running at the edge of its specs, since there was some evidence of heat there. Also, on the video output board, there was a poorly adhered heatsink that I reattached with a spec of super glue and a small gob of silicone fixant. It was kind of tipped over onto another chip and not doing its job - probably not an electrical problem.
I am glad, and hope for the future, that there is nothing wrong with the part that would normally encompass the inverter, because it is integrated into the LCD itself and runs the full width of the screen. If I were to be very careful, I could restore the bad caps and try to take advantage of Acer's (so far) excellent customer service and warranty service, but the way the monitor was constructed insured a lot of evidence is left of any repair work (special tapes, tricky plugs, etc - no seals though).
I have also had to do a capacitor replacement on my otherwise very nice Samsung SyncMaster 226BW. Thank goodness for forums!
By the way, I am down to a single machine running MythBuntu/MythTV as far as Linux goes, although I am constantly using various Live CD's for the ease of use, testing, and tools they provide. I also have a couple of Android devices, but haven't dug inside them much except to 'root', etc.
Thanks Liz also - the time was enjoyable, finding the parts helped me find some other stuff, and it worked! It goes very nicely with my Acer 23"LCD/LED.
DaveC
On 1/6/2012 11:51 AM, John Stoffel wrote:
Tim> Funny you say that. We have dozens of those monitors where I Tim> work and we pick one day a month and for about 2 hours we set up Tim> a assembly line. One person desolders the bad caps, another Tim> person solders on new ones, then we have one monitor we use as a Tim> test rig. We can crank them out at this point. Though we long Tim> ago figured which 5 caps are the likely culprits and we just Tim> replace them all, even if the cap looks good.
I love the Samsung 204Bs, I wish I could get more of them. Nice 1600x1200 display, pan/tilt/height adjustments, etc. Got any you want to sell?
John _______________________________________________ Wlug mailing list Wlug@mail.wlug.org http://mail.wlug.org/mailman/listinfo/wlug
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