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I hooked my Laptop to PC port via VGA cable and it works fine with a 3 foot cable. I got a 15 foot cable and the TV wil not detect the PC when I change source inputs.
It will work however, if I hook the 3 foot cable up, detect the PC and then swap cables. If I change sources again, it will not detect the PC again.
My questions. What is the longest cable that will work or is there a work around to this problem.Cut-Throat
Follow Ups:
Your laptop doesn't have enough drive to drive a longer cable, the work around is to use a VGA extender/booster. As far as the longest cable that would work, it would be difficult to know without knowing a lot of varibles. You could expirment with a few different lengths or try contacting the laptop manufacturer's technical support.
Here's a link for one but I'm sure there are many more on the net:
Once I detect the PC with the 3 footer and then swap out the 15 foot cable. The 15 foot cable works fine in every way.
I think it may be a timing thing when I change sources. Pushing the 'source' button on the remote the TV detects whether a device is hooked up such as an Antenna, DVD player or a PC - This is the only thing that the 15 foot cable does not do.
Cut-Throat
Yes I read your post and saw that the 15' cable works fine, I didn't say that there's anything wrong with it. It works but only after you enable the VGA receiver with the 3' cable so I reasoned that the 15' cable loads down the VGA driver/transmitter enough that it can't enable the receiver (on the TV) but once it is enabled with the 3' cable then it is much easier for the VGA tranmitter to drive the longer cable. Your "timing thing" doesn't really make sense to me. I don't think the TV detects anything when you change sources it just switches to that input. If it's the TV's problem why would the cable matter? If you have access to other brands of 15' cable you might try some of those. One of them might not load down the PC driver as much (less impedance) and it may even be that your cable is defective even though it works somewhat.
You are right! - Timing has nothing to do with it, but either does the length of the cable and making it 'much easier for the VGA tranmitter to drive the longer cable.' - BTW - I mistyped it is a 25 foot cable not 15.
OK, today I am thinking I will just buy a connector for the 2 VGA cables - so I could connect the 3 foot cable with the PC, disconnect the PC and then connect the 25 foot cable to the 3 footer and then connect the PC to the 25 footer and it should work.
Strange results. When I hooked the 3 foot cable up to the TV and then the 25 foot cable to the 3 foot. Everything worked perfect. So there is a difference between what is plugged into the TV from the 3 foot cable and the 25 foot cable. So the TV has no problem finding the PC with a total cable length of 28 feet. So I am closing in on the problem.
The obvious thing is that the 3 foot cable has the large 'bulges' close to the plugs and the 25 foot cable does not (it's a slim cable with no round cylindrical bulges near the plugs.) So, I am thinking that these bulges are ferrite cores, so I tried a small one I had on the 25 foot cable - but it does not work. Are there different VGA Plugs?
You know what's going on here?
Cut-Throat
You are right, the bulges are filters. Some applications will work without them but yours must be in a noisy electrical environment. The 25' length makes it even more prone to noise and it's probably not a sheilded cable either. I'm guessing that when you combine the two cables the filters (and sheilding) on the 3' cable is what is allowing all 28' to work but I'm puzzled as to why when you switch back to the long cable by itself it works. Perhaps the noise is only a problem on the initialization. If I'm understanding your question ["Are there different VGA Plugs?"], they are all the same D-type connector. Some are made of plastic and some of metal and depending on the application, some of the pins are crossed (ie. not pin-for-pin compatible).
I just installed a sub-panel and separate circuits about 1 year ago in my listening room. The power is exceptionally clean. There is something else going on here that we do not understand yet nor cannot explain. The cable is shielded also.
I will get to the bottom of it eventually. - But cable length has nothing to with it! - I have learned that!
Cut-Throat
A longer cable certainly doesn't help but I agree that the length doesn't seem to be the culprit in this case. Separate circuits certainly help to cleanup the power but they don't block everything, you still have junk comming in from the main powerline. Also, noise (EMI/RFI) comes from everywhere not just your powerline. Your TV could even be emitting noise. A refrigerator, switching power amps, an air conditioner, any electric motor or generator, etc. You have narrowed the problem down to the cable so why don't you barrow two 25' cables. One with filters and one without and try them both. If both work then your cable was defective. If only the one with the ferrite cores works then you have a noise problem. If neither work then it's something else although I would find that hard to believe after your experiment.
After some troubleshooting with an electrical supplier here, they figured out why my 25 foot cable would not work right with my TV.
It turns out that the Cable that I had with my DLP projector is wired differently than the 25 foot cable. I think what he told me is that pin 4 is tied to the shield (ground) and all the other pins are tied to ground individually on my 3 foot cable. On my 25 foot cable the pins are not tied to the shield but just wired one to one. This was a common problem of the Monitor not being able to detect laptop computers in general. They do make an adapter so that cables such as my 25 footer will work. They have ordered me an adapter.
Cut-Throat
Thanks for the info, that's good to know. I guess the shield is used as the common ground. I never thought of something like that but I should have thought of suggesting to buzz out each cable for differences.
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