|
This tutorial on Static Electricity hazards to the WebTV Plus "Video IN" circuit has been prepared by:
John Edw. Gulow
dba: "Internett Associates"
57 Old Academy Road
Chatham, MA 02633
E-mail: Internett_Assoc@webtv.net
I-A WebTV Hot-Line: [508] 945-4234
Internett Associates is a WebTV reseller, located on Cape Cod, offering in-home WebTV installation and tutorial instruction services. Internett Associates also teaches courses on WebTV use, provides lectures and program presentations about WebTV to service and community organizations, and sponsors "WebTV Clubs" featuring FREE monthly meetings at local community Senior Centers open to all WebTV users and those interested in learning more about WebTV features, operation and capabilities. In nearly 10 years of operation, we have installed almost 400 WebTV systems and serviced a number of other settop Internet Appliances including AOLTV, I-Opener, MailStation, WebPal, PostBox and more. As independent local WebTV advocates, we are a group of retirees who bring years of prior engineering and personal computer experience and understanding to our support and tutoring services.
|
1. Why the Video IN gets "Fried"...
WebTV Plus users continue to "fry" their Video IN circuits because little or no consideration is given to "Static Electricity Discharge". While WebTVs can and do fail for various "Surge" and Lightning causes, the specific failure of the Video IN circuit would lead one to conclude that another cause needs to be dealt with....that is "Static Electricity".
Download of a picture from a VideoCam or a Digital Camera or a VCR requires that the WebTV be connected to the picture source using a cable. Therefore, the Video OUT of the picture source device must be electrically connected to the Video IN of the WebTV Plus...and the wiring interconnection between the two is a cable known generally as a "Video Cable."
Next, it must be understood that all objects in nature are charged with Static Electricity...more or less, depending upon materials, temperature and humidity. Think of a Static Electricity Discharge as a mini lightning strike...like when you pet a cat's fur in the winter and then touch the cat's nose...and "snap", the small spark jumps from your finger tip to the cat's nose [and the cat doesn't like it]. Static Electricity charges can easily range into the tens of thousands of volts that are harmless to humans but can and do instantly destroy sensitive unprotected Integrated Circuit electronics. Static Electricity Discharges take place whenever the Static Electricity charge on one item is different from the next item...like when you touched the cat's nose. Technicians and workers handling sensitive electronics work in controlled manufacturing areas that are designed to avoid Static Electricity damage and wear special clothing and have grounding wrist straps to prevent Static Discharges from destroying the electronics they touch and handle.
Integrated Circuit [IC] electronics are generally designed for very low voltages, usually well under 100 volts...and where exposed to external high voltages, require very specific protective measures designed into the IC. I suspect that the WebTV Plus Video IN connection is a relatively unprotected IC that cannot handle extreme high external input voltages. As a result, any Static Electricity voltage discharge that takes place within the IC then locally instantly damages a small section of the Video IN circuit....just like a fuse "blows" when exposed to a high current. Since the damage is very local, all other WebTV functions appear to be unaffected. ..but the Video IN function is lost forever and is not repairable...it has been "fried".
Thus it is the difference in Static Electricity voltages between any two objects...here, between the WebTV Plus Video IN circuit...and, the Cable connected to the VideoCam or Digital Camera or VCR... that needs to be equalized...made identical, so when connected together there is no discharge that can take place within the WebTV's IC electronics.
The solution then to protecting your WebTV Plus Video IN from Static Electricity discharge damage is to assure that the Static Electricity voltages present are safely equalized before the connection[s] are made...and fortunately, this is pretty easy to do.
|
2. Connecting to the WebTV's Video IN
The procedure that follows is designed to equalize Static Electricity voltage charges that may exist between a VideoCam [or Digital Camera, or VCR] and the WebTV Plus Video IN circuit. The steps outlined should be done in the sequence as follows:
1. Make sure that your WebTV Plus is powered OFF [no Green lite showing on the front panel].
2. Make sure that the picture source [Digital Camera, or VideoCam, or VCR] is also powered OFF.
3. Connect the picture source's "Video Cable" to its Video OUT connector.
[Note: Video Cables are of various design depending upon the picture source device...they may have either colored RCA Plugs [Yellow-White and Red] or a mini Plug that contains Video and Audio connections.]
4. If the remaining unconnected end of your Video Cable has a White RCA plug, you may connect that directly to the White Audio IN RCA connector at the back of your WebTV Plus. Audio IN circuit connections are not as sensitive as the Video IN circuit.
5. If the remaining unconnected end of your Video Cable has a Red RCA plug, you may connect that directly to the Red Audio IN RCA connector at the back of your WebTV Plus. Again, Audio IN circuit connections are not as sensitive as the Video IN circuit.
6. Examine the remaining Yellow RCA plug at the unconnected end of your Video Cable. Note that it has a projecting center metal Pin that is surrounded by an outer metal ring. Grasp the Yellow Plug and touch the center pin and outer metal ring to any exposed bare metal part at the rear of your WebTV Plus [such that both the center metal Pin and the outer metal ring are both touching a bare metal part of the WebTV Plus at the same time]...you can use either of the metal Screw-type coax cable connectors if bare metal is exposed there, or you can [as I do] use the outer bare metal ring of the Yellow Video IN RCA connector. The purpose here is to "short" the Video Cable center Pin to its outer metal ring...and to short those two to the bare WebTV Plus bare metal at the same time...thus shorting/equalizing the Static Electricity voltages between the two.
7. Then, immediately plug the Yellow Video Cable plug into the WebTV Plus Yellow Video IN RCA connector...and your connections are now safely made.
8. You may now turn your WebTV Plus ON by pressing the keyboard WEB button and proceed to the usual Mail screen where you can select to download your pictures by choosing PHOTO.
When done downloading pictures, you may leave the WebTV connected to your picture source, leaving the Video Cable as is, in place. However, if you wish to disconnect the picture source [VideoCam, or Digital Cam, or VCR], then you may simply remove the Video Cable connections from your WebTV...disconnect any WHITE/RED Audio Plugs first and then disconnect the YELLOW Video Plug last.
NOTE: DO NOT LEAVE THE VIDEO CABLE CONNECTED TO THE WEBTV PLUS AND DISCONNECTED FROM THE PICTURE SOURCE!!! In leaving the Video Cable connected by itself to your WebTV Plus, you risk having a Static Electricity charged object touch the exposed Video connection of the cable's unconnected plug end...and POOF, in a moment you can inadvertantly destroy ["fry"] the WebTV's Video IN circuit.
|
3. DISCLAIMER
The procedure outlined above has been used by this author many hundreds of times in downloading pictures from both Digital Cameras and VideoCams. During a period of several years, no instance of a "fried" WebTV Plus Video Input circuit has occurred.
This procedure was developed recognizing the susceptability of Integrated Circuit electronics to Static Electricity discharges and is an attempt to minimize, if not eliminate such problems when using the WebTV Plus.
This procedure is published for the benefit of other WebTV Plus users however, the author takes no responsibility for any adverse experiences that any user may encounter. Use of these procedures is entirely at the risk of the user.
It is believed that Static Electricity Discharges may also be responsible in part for "fried" Video IN circuit occurrences experienced by users of the short-lived "H-P eScanner". This author has no personal experience using an eScanner and therefore cannot confirm any performance improvement or failure avoidance by using the outlined procedures.
The author also believes that other consumer electronics devices may also be susceptable to Static Electicity Discharges to varying degres...ie VCRs, etc and believes it is prudent to follow the same/similar procdures when making connections to all Video IN circuits.
|
|