Image is too much bright at high refresh rate
Hi.
I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. When I put 70Hz the image is good. What can be causing this problem? The monitor is connect to S3 video card. []s -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W (GMT -2 (BRST) / GMT -3 (BRT)) "Two of the most famous products of Berkeley are LSD and Unix. I don't think that this is a coincidence." -- Anonymous |
On Tue, 14 Dec 2004 00:20:41 -0200, Chaos Master
put finger to keyboard and composed: I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. Do you mean retrace lines? - Franc Zabkar -- Please remove one 's' from my address when replying by email. |
On Tue, 14 Dec 2004 00:20:41 -0200, Chaos Master
wrote: Hi. I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. When I put 70Hz the image is good. What can be causing this problem? The monitor is connect to S3 video card. []s -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W (GMT -2 (BRST) / GMT -3 (BRT)) "Two of the most famous products of Berkeley are LSD and Unix. I don't think that this is a coincidence." -- Anonymous Get an engineer to slightly turn down the flyback screen control to see if will adjust it,it should. |
"Harry Hotspur" wrote in message ... On Tue, 14 Dec 2004 00:20:41 -0200, Chaos Master wrote: Hi. I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. When I put 70Hz the image is good. What can be causing this problem? The monitor is connect to S3 video card. []s -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W (GMT -2 (BRST) / GMT -3 (BRT)) "Two of the most famous products of Berkeley are LSD and Unix. I don't think that this is a coincidence." -- Anonymous Get an engineer to slightly turn down the flyback screen control to see if will adjust it,it should. That's not a fix, he said it's brighter at a higher refresh rate, which is unusual, normally it becomes darker. Did the problem happen gradually? Does it change at all as the monitor warms up? If so I suspect a capacitor is failing, if it happened suddenly then I'd look for a cracked solder joint around the HV section or a shorted transistor in the regulator. |
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Hi!
I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. When you run a a monitor at the maximum supported scan rate for a given resolution, you may find that it doesn't always run well, especially when you get to the upper ends of the monitor's abilities. Sometimes that is just the way it is--other times the monitor may have worn components that can't handle what they once were designed for. Have you checked to see what happens at 75Hz in lower resolutions? What can be causing this problem? The monitor is connect to S3 video card. The video card shouldn't be a factor in this, so long as it basically works. I have here a Trio64V2 with 2MB VRAM running a cheap-o Dell 17 inch monitor at 1024x768/75Hz vertical. I didn't know that those early S3 video chips were capable of that high a scan rate, but it will go to 85Hz if I select that. William |
On 14 Dec 2004 13:33:54 -0500, Sam Goldwasser
wrote: (Harry Hotspur) writes: On Tue, 14 Dec 2004 00:20:41 -0200, Chaos Master wrote: Hi. I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. When I put 70Hz the image is good. What can be causing this problem? The monitor is connect to S3 video card. Get an engineer to slightly turn down the flyback screen control to see if will adjust it,it should. If it happened suddenly, it's not an adjustment but a power supply, deflection, or video problem. IF you adjust the screen/G2 control, it will probably mess up other refresh rates making them too dark, and is likely just masking some other problem. --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/ Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/ +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html Note: These links are hopefully temporary until we can sort out the excessive traffic on Repairfaq.org. Important: Anything sent to the email address in the message header is ignored. To contact me, please use the Feedback Form in the FAQs. I wasn't aware he said it happened suddenly,diffence between 70 Hz and 75HZ is small.I know the screen control may have a problem,a small tweak on the flyback pot should not mess up other refresh rates to any extent.As you know it's a very fine adj.to blank out retrace lines,if he wants to run on his said 1024x768 I think the result will be sufficient for most people,coupled with brightness and contrast control. If he wants to go into employing us to check out all the screen feeds then it's cheaper to buy another monitor as it is 15" and 6 years old.Just trying to advise a cheap remedy for him. |
Franc Zabkar squeaks:
I have 15" CRT monitor VISION DX-1564 (~1998), operating at 1024x768. It supports refresh rate of up to 75Hz at 1024x768 and 60Hz at 1280x1024. I wish to use 75Hz refresh, but when I put 75Hz refresh rate, the image has very bright lines. Do you mean retrace lines? OK, most likely, I didn't knew the term in English. -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W "People told me I can't dress like a fairy. I say, I'm in a rock band and I can do what the hell I want!" -- Amy Lee NOTE: messages are automatically sent after 00:00AM! I'm on dial-up! NP: nothing (Winamp is stopped) |
James Sweet squeaks:
Get an engineer to slightly turn down the flyback screen control to see if will adjust it,it should. That's not a fix, he said it's brighter at a higher refresh rate, which is unusual, normally it becomes darker. Did the problem happen gradually? Does it change at all as the monitor warms up? If so I suspect a capacitor is failing, if it happened suddenly then I'd look for a cracked solder joint around the HV section or a shorted transistor in the regulator. Doesn't change as monitor warm up. But I will have to check for those failed components as the monitor is old and suffered some heavy usage. []s -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W "People told me I can't dress like a fairy. I say, I'm in a rock band and I can do what the hell I want!" -- Amy Lee NOTE: messages are automatically sent after 00:00AM! I'm on dial-up! NP: Lacuna Coil - Heaven's A Lie |
William R. Walsh squeaks:
When you run a a monitor at the maximum supported scan rate for a given resolution, you may find that it doesn't always run well, especially when you get to the upper ends of the monitor's abilities. Sometimes that is just the way it is--other times the monitor may have worn components that can't handle what they once were designed for. Maybe this is the problem, this monitor is cheap monitor, maybe it was designed without 75Hz in mind? Have you checked to see what happens at 75Hz in lower resolutions? The image is good on 800x600@75Hz. What can be causing this problem? The monitor is connect to S3 video card. The video card shouldn't be a factor in this, so long as it basically works. I have here a Trio64V2 with 2MB VRAM running a cheap-o Dell 17 inch monitor at 1024x768/75Hz vertical. I didn't know that those early S3 video chips were capable of that high a scan rate, but it will go to 85Hz if I select that. I know, but I just put this for completeness. -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W "People told me I can't dress like a fairy. I say, I'm in a rock band and I can do what the hell I want!" -- Amy Lee NOTE: messages are automatically sent after 00:00AM! I'm on dial-up! NP: Lacuna Coil - When A Dead Man Walks |
Harry Hotspur exposed:
I wasn't aware he said it happened suddenly,diffence between 70 Hz and 75HZ is small.I know the screen control may have a problem,a small tweak on the flyback pot should not mess up other refresh rates to any extent.As you know it's a very fine adj.to blank out retrace lines,if he wants to run on his said 1024x768 I think the result will be sufficient for most people,coupled with brightness and contrast control. I will use 70Hz for a while, until I buy a LCD monitor (in 6 months or so), maybe then I will leave this monitor for usage as 2nd monitor. []s -- Chaos Master®, posting from Canoas, Brazil - 29.55° S / 51.11° W "People told me I can't dress like a fairy. I say, I'm in a rock band and I can do what the hell I want!" -- Amy Lee NOTE: messages are automatically sent after 00:00AM! I'm on dial-up! |
Hi!
Maybe this is the problem, this monitor is cheap monitor, maybe it was designed without 75Hz in mind? It's certainly very possible. I've seen a lot of monitors that didn't run well close to their limits. There's one line of 14/15 inch monitor that sticks out though--some Sampo-made Dell Ultrascan displays. These were great monitors in my experience. Every one of them I had would run 75Hz at 1024x768 with no problems and 85Hz at 800x600. There were only a few weak points--these monitors needed some new capacitors after a few years and the signal cables were easy to break. Other than that these were nice basic monitors with good pictures. You might see if you could find one. The image is good on 800x600@75Hz. Almost certainly a weakness of the monitor or getting close to its limits. This behavior could indicate a minor problem developing, but until the behavior gets worse, it would be hard to say. I know, but I just put this for completeness. Same thing here. Just wanted you to know what I've used here. William |
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