Dual Monitors Not Working

I have been using 2 monitors at the same time for awhile now. I have a home-built desktop pc running Windows Vista Ultimate 32-bit OS. My monitors are an Optiquest and a ViewSonic. This past week one of my monitors went out, but I trouble shot and both monitors are functional. I can switch them in the "Display Settings" option and both work, but just not at the same time. One will display "no signal" while the other will work. I was thinking this might be a graphics card issue, but in Device Manager nothing is checked with regards to display adapters. My graphics card is a NVIDIA GeForce 8800 GTS. I also thought this might be a power supply issue, but am unsure of how to troubleshoot any of this. Any suggestions would be most appreciated...Thanks! Geeks Rule! Shanrene

 

Have you gone into the Nvidia control panel and checked to see if you still had dual monitors setup?

 

Does your video card have dual output or are you using 2 different cards? Unlike windows xp, Vista only allows dual monitors to work if both cards use the exact same driver. If you are using two cards I would suggest reinstalling the drivers.

David

 

Shanrene has stated the computer has "a card".

That's not true. There are some restrictions where all of them must use the same WDDM driver, but there are ways around that. See Multimonitor Support in Vista. But again, he is using one card.

But most importantly for this thread, Shanrene has reported everything worked just fine for some time, now suddenly does not.

In Display Settings, when you select Monitor 2, is the Extend the desktop onto this monitor box checked?

Have you verified multimonitor setup is still enabled in the NVIDIA Control Panel, and that what you think is Monitor 1 is Monitor 1?

If this problem started just a couple days ago, you might consider using System Restore to roll back to a previous Restore Point.

Here's my canned text on testing power supplies:

To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies. This is done by a qualified technician using an oscilloscope or power analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronic repair facilities.

Fortunately, there are other options that are almost as good. I keep a FrozenCPU Ultimate PSU Tester in my tool bag when I am "in the field" and don't have a good spare power supply to swap in. While not a certain test, they are better than nothing. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within specified ATX Form Factor Standard tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, it is not a true load or suitable for conclusive testing.

As mentioned, swapping in a known good supply is a tried and trued method of troubleshooting used for years, even by pros. Remove the "suspect" part and replace with a "known good" part and see if the problem goes away.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure, or reveal any unwanted and potentially disruptive AC components to the DC voltages.

And remember, anything that plugs into the wall can kill. Do not open the power supply's case unless you are a qualified electronics technician. There are NO user serviceable parts inside a power supply.

 

And furthermore, power supplies store deadly voltages for a long time after being powered off, just as CRT monitors do.

So you may not only fry the power supply by opening it up, you may fry yourself as well.

 

Supplies are supposed to bleed any stored voltage off almost immediately. But, even the best made supplies from the most reputable companies can be faulty, or fail. And sadly, there are many supplies that are assembled in obscure, unsafe factories in distant lands by under-trained, often under aged, forced labor :cry:mad - driven by unscrupulous factory owners under the watchful eye of corrupt government officials using parts made in sister factories in the next village up river. I wish that were just BS, but sadly, it is all too often true.

 

Well, not all are like that, I believe PC power and cooling is made here in the US of A.

 

Fortunately not. But too many builders, especially first time builders looking to cut costs, buy the cheapest PSU they can find, and that's a mistake. Also a problem is many case retailers "toss in" a budget supply just to make a case sale - even with quality cases. I often recommend people buy a case for the case, with the full intention of pulling the off-brand PSU and replacing it was good one from a reputable maker. The generic can always be used for testing fans, or drive motors, or Christmas lights!

They certainly used to be, but I would not be surprised if they don't contract out to a factory overseas - but that does not mean it's a bad thing. Many quality parts are made elsewhere - it all depends on the management and how much they invest in quality control. And certainly PC P & C is well known for quality and has a fine reputation for making quality PSUs. They made their mark by debunking the hyped-up myths about multiple rails as all their supplies use a single rail. But they are a subsidiary of OCZ Technology (also known for quality - memory mostly), which is a global company - so you never really know.

I guess this is a good point to toss in one of my canned texts. The following helps folks determine the right size for current and future needs, and selecting a good brand.
***

Use the eXtreme PSU Calculator Lite to determine your power supply unit (PSU) requirements. Plug in all the hardware you think you might have in 2 or 3 years (extra drives, bigger or 2nd video card, more RAM, etc.). Be sure to read and heed the notes at the bottom of the page. I recommend setting Capacitor Aging to 30%, and if you participate in distributive computing projects (e.g. BOINC or Folding@Home), I recommend setting TDP to 100%. These steps ensure the supply has adequate head room for stress free operation and future demands. Research your video card and pay particular attention to the power supply requirements for your card listed on your video card maker's website. If not listed, check a comparable card (same graphics engine and RAM) from a different maker. The key specifications, in order of importance are:

1. Current (amperage or amps) on the +12V rail,
2. Efficiency,
3. Total wattage.

Then look for power supply brands listed under the "Good" column of PC Mechanic's PSU Reference List. Ensure the supplied amperage on the +12V rails of your chosen PSU meets the requirements of your video card. Don't try to save a few dollars by getting a cheap supply. And don't count on supplies that come included with a case. They are often underrated, budget or poor quality models "tossed in" to make the case sale. Digital electronics, including CPUs, RAM, and today's advanced graphics cards, need clean, stable power. A good, well chosen supply will provide years of service and upgrade wiggle room. I strongly recommend you pick a supply with an efficiency rating equal to, or greater than 80%. Look for the 80 Plus - EnergyStar Compliant label. And don't forget to budget for a good UPS with AVR (automatic voltage regulation), as surge and spike protectors are inadequate.

 

To add to this, consider if you may be running an SLI/CrossFire card setup at any time in the near to moderate future. If you are, then try and spend the extra money for an SLI/CrossFire certified supply. It is worth having the extra power/capability there even if you decide not to use it, because you may just as easily decide to use it, and then you have saved money on the supply in the first place.

 

That's a tricky and confusing point. Many PSUs are coming with SLI/CrossFire certifications these days. However, when it comes to PSUs, that certification does not mean anything special in terms of minimums for voltage, wattage, or current. All that certification really means is the maker sent the PSU to NVIDIA and AMD/ATI, paid them a fee to have them test it to make sure it meets ATX electrical standards. Additionally, and perhaps more importantly for the consumer, it tells consumers the PSU will have the necessary cables and connectors to connect two cards. It does not mean it will be of higher quality (or power rating) than a PSU without the certification. In other words, for PSUs, it is a marketing gimmick that simply allows the PSU makers (or forces them to pay) to put the SLI and Crossfire stickers on the box! ANY PSU with sufficient power that meets normal ATX standards, and has the right connectors (or adapters) will work in a SLI or Crossfire configuration.

Same thing with RAM. RAM does not have to be SLI or Crossfire certified to run two cards in SLI or Crossfire configurations. So if you see RAM that is SLI or Crossfire certified, it's just an advertising gimmick to make you think you are getting superior RAM. There are no protocols or programmed firmware requirements for PSUs or RAM that make them compatible, or not, with SLI or Crossfire cards.

So bottom line, the SLI/Crossfire certificate probably means it is not a generic PSU, and that it has the necessary cables. That's it. It does not mean higher quality, and it does not mean more power than a non-certified PSU.

 

Sorry, I didn't think about that when I posted. I forgot that this was just a gimmick. Ah well, such is life.

 

Yes, but is it Windows 7 ready?

 

Mine is!:-D

 

Mine too. And I'm liking it.