Projects Archive

Troubleshooting a Refurbished HP W2338H

Posted November 10, 2012 By Landis V

Back in December of 2009, I purchased a “Famous Maker” refurbished 23″ monitor from Woot, which turned out to be an HP W2338 relabeled as a TSS TS-23W8H.  The monitor has worked well and I have been very happy with the display for the past three years.

Recently, however, we attempted to switch over to another system on the KVM switch, heard a faint sizzling noise for a couple of seconds, and the power indicator changes back to amber with no display.  My initial assumption was that the power supply had gone south, so we (and by we, I mean Nicole, because I’m usually on my laptop) used the iMac until I had a chance to disconnect the HP monitor and resurrect from storage the 19 1/2″ Acer that preceded it.  Today, I finally dove in to the diagnosis and repair process.

Almost right out of the gate, I was thwarted in the disassembly process, leading me to cross reference the TSS part number on the monitor sticker to the original HP part number.  Further searching led me to a YouTube video link on  this page, showing that my assault from the rear of the monitor would be fruitless.  The text within the video is in Spanish, but the information provided is clear and useful regardless.

[iframe src=”http://www.youtube.com/embed/A8XV4L0klO8″]

While the model numbers weren’t an exact match, this was clearly the same housing design.  I was unable to duplicate the nonchalance with which the technician in the video removes the bezel from the front of the display, but finally got one corner to release after tugging much harder than I was reasonably comfortable with, after which the remaining edges followed easily.  The video does a good job documenting the remainder of the disassembly process.

Removal of the main display encasement and disconnection of the associated cables proved relatively straightforward, and led to the realization that the monitor has built-in speakers.  I had not looked closely enough at the connections previously to see the audio in jack.  We may give these a try after the monitor is repaired and reassembled.  After removing the outer panel containing the logic boards for the panel and inspecting the logic boards, I decided to continue on to examine the CCFL’s, as there was nothing visually obviously wrong with the inverter.  Blown caps seem to be a common mode of failure for this monitor, and had any of them been swollen I probably would have looked into a replacement kit.

Phosphorus spray on LCD reflective metal backing

The back of the main LCD panel is labeled with a sticker indicating that it is a Samsung LTM230HT01 – which accounts for the quality of the picture; I have always been pleased with Samsung displays.

After removing the reflective metallic backing for the main LCD panel, it quickly became clear that my problem is most likely a broken CCFL tube.  As you can see in the image at right, there is grayish-white residue distributed across the top right corner of the metal backing plate, characteristic of a fluorescent bulb that has broken but is still sufficiently closed to allow it to sputter and leak.  I believe this residue is a combination of phosphorus and mercury that has escaped from the lamp during the few times we tried to get the monitor to kick on again.  Handle with care!

Shortly after removing the back panel, my suspicions were finalized that this is indeed a CCFL problem.  One of the tubes is cracked through and will require replacement.
Crack near end of CCFL tube

There’s some good information in this thread about testing and replacement of the components.  I’ve located a couple of potential sources for the CFLs, which are indicated to be 535mm (haven’t confirmed diameter yet)- Plazmo Industries out of Omaha on eBay, CFL Warehouse, and Backlight Company (who appear to stock both 3.0mm and 2.4mm diameter versions).  I haven’t completely ruled out the idea of upgrading from CCFL to LED technology as suggested at lcdparts.net, though they don’t have anything of the correct size and the closest options to it appear prohibitively expensive.  It would also be possible to build an LED strip or matrix myself, but my lack of familiarity with the best performing LEDs in this scenario (for brightness, whiteness, energy consumption, heat dissipation, and lifetime) lead me to avoid such an undertaking.

UPDATE 2012-11-20

Dug out my micrometer and measured in at ~5/64″, or approximately 2mm.  I may have some further searching to do in order to locate a 2mm tube, as I don’t believe any of the ones I ran across previously were that diameter.  Out of curiosity, I also measured the length, and it turned out to be about 20 1/4″, or approximately 515mm between the silicon caps… doesn’t match with what my other sources had indicated.  It might be as much as 20 1/2″ or even 20 5/8″ inside the caps.  Since they will need to come off anyway, I went ahead and peeled back the silicon caps.  Unfortunately I destroyed one in the process… so that partially answers the question on # of CCFL’s to purchase as “at least two” since I will be removing the other one to replace the cap in any case.  The most accurate measure I could come up with is 20 11/16″ from tube end to tube end, which equates to approximately 525mm.  It also appears that they placed a small heat shrink boot over the connections at one end of the tubes, which is also a good idea.

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Belkin ShareMax N300 Follow-ups

Posted June 3, 2012 By Landis V

As I mentioned in an earlier post, I bought one of these little 4-port wireless routers with a gigabit switch to use primarily as a NAS server.  I’ve been so happy with it that, when I recently discovered the need for a light duty broadband router and firewall on a loaner basis, I decided to pick up another one.  With the original, I took the firmware to a Tomato version and I have found it very pleasant to work with, so I plan to do the same.  I recall having a few problems getting it where I wanted it to be, so I’ve decided to make some notes on my steps through the process this time around.  I think I may have actually attempted a direct flash to the Tomato firmware the first time, and had to perform a recovery, so I’m going to “follow the directions” this time around 🙂  Much of the instruction comes from the FatWallet forum thread at http://www.fatwallet.com/forums/expired-deals/1180400/?start=0, and specifically this post and (primarily)  this post on page 3 of the discussion.  There’s also a good link discussing recovery in between those two posts should you happen to brick a box.  I just wanted to clean these up and put them in a slightly more organized fashion than sometimes happens in a forum thread, as well as document the steps that worked for me.

Please note that I disclaim any and all liability for any damage or loss, direct or indirect, as a result of these instructions.  These notes are primarily for my own benefit and may or may not work in your individual circumstances.  You acknowledge that installing third party firmware is an unsupported action and accept full responsibility for any problems or costs resulting therefrom.

  1. I transferred copies of the following files, which I had previously downloaded, to the laptop I planned to use for the process:
    • dd-wrt.v24-18946_NEWD-2_K2.6_mini_f7d3301.bin (other versions may work, your mileage may vary)
    • dd-wrt.v24-18946_NEWD-2_K2.6_mega.bin (as above, other versions may work, ymmv)
    • tomato-K26USB-1.28.7497.IMIPSR2-Toastman-RT-Ext.trx
  2. Connected the Belkin to the laptop via ethernet, booted it up, and disabled wireless, since I don’t need it in this instance and it is interfering with the wireless connection I’m using to read up as I go.  Hard set the IP on my laptop to 192.168.2.10 with a mask of 255.255.255.0.
  3. Logged into the Belkin at 192.168.2.1.  I disabled wireless because it won’t be needed in my scenario, and because it was interfering with the laptop I was using for reference on a wireless connection to my operational network.  Saved config and restarted the router.  These steps shouldn’t be necessary in most cases.
  4. Logged back into router, browsed filesystem for, and uploaded DD-WRT mini firmware referenced above, via Utilities section, Firmware Update (had to “submit” blank password, as I had not set one). (picture)
  5. As noted in the forum instructions, I waited about 10 minutes.  Then set static IP on laptop of 192.168.1.10 (same mask as above) and attempted to open browser to DD-WRT admin page at 192.168.1.1, successfully.  The router immediately presented a page indicating an unsafe username and password, which it would not allow me to proceed without changing.  Set username and password to a known but simple value.
  6. Proceeded to Administration tab (prompted for, and entered, username and password specified above), then the Firmware Upgrade subtab.  Set the “After flashing, reset to” box to “Reset to Default settings”, browsed for the dd-wrt mega file noted above, and proceeded with the upgrade.  The router completed the upload in approximately the 300 seconds it indicated, then provided a screen with a progress bar indicating the router was restarting.  I noted that a ping I had running to the router dropped shortly after that screen appeared.  Ping remained down even though the status screen indicated that it should be back online.  Router still appeared in ARP cache, and upon clearing ARP cache on the PC and restarting ping, the entry returned but I remained unable to connect to the device.
  7. Pulled power from the router at the wall outlet.  Waited at least 30 seconds, then reconnected.  Ping resumed a few seconds later, and I was then able to open the web interface.  Was again prompted that username/password was unsafe and again entered a simple combination in order to proceed.  Observed that the router did indicate it is on the “mega” firmware in the top right corner of the page.
  8. After entering password, returned to Administration tab, Firmware Upgrade subtab, set same option to “Reset to Default settings”, located and uploaded the Tomato firmware file.  Router again indicated that it was uploading the file for approximately 300 seconds, then produced “upgrade successful” screen indicating it was restarting.  As before, ping dropped, but this time only briefly.  Was prompted for username/password, entered the combo I had set above, and was provided with a screen to continue to the web administration page (prompt indicated the webserver was “DD-WRT”, which indicated the upgrade was not completely successful).  Upon clicking continue, received username password requests again and was unable to proceed with the previously entered username and password.
  9. Hard pulled power at the wall again for a minimum of 30 seconds.  Restored power, continued to see indication that the network cable was unplugged.  Tried power pull one more time with same results – light on on front of router, but computer indicating that there was no cable connected and no ping replies or arp entries.
  10. Proceeded with 30/30/30 reset (see below).  Did observe that I was getting replies from 192.168.1.1 with a TTL of 100 after approximately the first 30 seconds, and the same after restoring power and continuing to hold reset for 30 seconds.
  11. Attempted to open a browser to 192.168.1.1, and received the CFE miniWeb Server with a location to provide a firmware file.  Browsed to the firmware file, then uploaded.  Noted that ping response times increased from ~1ms to between 6 and 10ms, then back to 1 or 2 ms after a couple of minutes.  Noted that the web interface advised that the firmware file provided was not a valid firmware image.
  12. Selected “Continue” in the advisory page, issued the command from the miniWeb server to restore default NVRAM values.  Restarted router from the CFE miniWeb page.
  13. Amazingly enough, after restarting and attempting to access default page at 192.168.1.1 again, was provided with a password prompt, entered the password I had set previously, and was provided with the Tomato router interface.  How about that.
  14. Updated username and password to something more secure, and proceeded with my configuration.

Notes

Instructions are for the Belkin Share Max N300 (F7D3301/F7D7301) v1.

The two DD-WRT files are out of order when you browse for the files (mega is alphabetically before mini… keep it in mind)!

30/30/30 reset method:  Hold down reset button for 30 seconds.  While continuing to hold reset, power off by unplugging from wall outlet and leave unpowered for 30 seconds with reset held.  Without releasing reset button, restore power to modem; wait 30 seconds, then attempt connection to web interface again.

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MythTV, XBMC, misc.

Posted May 11, 2012 By Landis V

https://help.ubuntu.com/community/MythTV/Install/Server/Backend

http://wiki.xbmc.org/?title=MythTV

Seriously, can’t Mac just use Ctl+V/Ctl+X/Ctl+C?  Thought they had a “control” key as well, in addition to the poison apple and the cloverleaf.  Guess I’ll have to check.

After a bit of a hiatus, getting back into MythTV a little bit.  This time, just going to set up backend on a PC I always have running anyway, and as noted in the second link, run XBMC as a Myth frontend.  Since I finally bought a TV from the modern era, I ordered a video card with an HDMI output and am thinking I can get an XBMC set up as a frontend so we can DVR the very small handful of shows I actually kind of give a damn about watching.

I’ve also been doing some research and playing with Joomla, as it seems like it may be a better platform for my most recent web endeavor than WordPress.  As much as I like WordPress and am relatively comfortable with it, there are some layout things that I think would take additional work in WordPress that I can just do or use a plugin for in Joomla.  I could probably make WP do what I want, but I think I’d probably have more time in that than I would in learning Joomla and implementing the plugins I need to deliver the experience I’m looking for.  Plus, without digging into the backend and really building an understanding of the platform, I’m not comfortable with my ability to build out the changes I want securely.  At layer 2 or 3 of the OSI, I have enough experience to trust my judgment, even cross platform.  At layer 7 (8?), I question myself a little more.  I’m not comfortable in situations where I can’t trust my own judgment.

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http://ns2.sshlab.com/75949-belkin-share-wireless-gigabit-router-ddwrttomato-expansys/

Bought one of these fellas to act as a host for my new ioSafe 2TB unit.  Will be flashing either DD-WRT or Tomato.

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DNS Hosting Providers

Posted February 7, 2012 By Landis V

GoDaddy – $2.99/mo, generally feature rich, does lack dynamic DNS support.

ZoneEdit – quite possibly free for present needs, supports dynamic DNS.

Dyn – $30/yr, easy/obvious client support, some (admittedly high) limitations on querys and the like.

easyDNS – $20/yr, appears to support dynamic, (high) limits.

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