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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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Dell P991 Monitor Problem - seeking help
Hi Group,
My PC Monitor is a DELL Multiscan P991. About 2/3 years old. Just about useable in its present condition. It suffers from the following symptoms: 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always I have some electronics experience so taking the back off the monitor is no big problem. I know about the hi voltages etc etc. I am hoping that the above symptoms will be instantly recognisable by an expert as either some internal adjustment I can make or some component starting to fail and needing replacement. Any comments or advice would be very welcome please. Ger |
#2
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This sounds like problems in the CRT bias circuits, or in the HV multiplier.
The multiplier on most monitors is located on the side of the HV transformer (flyback). You must first check the biases to the CRT, and verify if they are in specs. This may be difficult to determine without the service manual. The G2 (screen bias) to the CRT, and also the high voltage are important to verify. -- Jerry G. ====== "Ger" wrote in message ... Hi Group, My PC Monitor is a DELL Multiscan P991. About 2/3 years old. Just about useable in its present condition. It suffers from the following symptoms: 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always I have some electronics experience so taking the back off the monitor is no big problem. I know about the hi voltages etc etc. I am hoping that the above symptoms will be instantly recognisable by an expert as either some internal adjustment I can make or some component starting to fail and needing replacement. Any comments or advice would be very welcome please. Ger |
#3
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On Mon, 8 Nov 2004 21:01:40 -0000, "Ger"
wrote: Hi Group, My PC Monitor is a DELL Multiscan P991. About 2/3 years old. Just about useable in its present condition. It suffers from the following symptoms: 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always I have some electronics experience so taking the back off the monitor is no big problem. I know about the hi voltages etc etc. I am hoping that the above symptoms will be instantly recognisable by an expert as either some internal adjustment I can make or some component starting to fail and needing replacement. Any comments or advice would be very welcome please. Ger Did you run the "color restore" function in the menu? It usually fixes this problem. Andy Cuffe |
#4
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Andy Cuffe wrote in
: 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always As long as the back is open (I presume it is) look toward the rear, left or right, for a large transformer with two adjustment screws on it facing the rear. USING A PLASTIC TIP, turn the LOWER (screen) adjustment CCW and the thin lines will hopefully disappear. The upper adjustment is for focus. Hope this takes care of your problem. BubbaJim |
#5
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Folks, many thanks for all the advice - off now to see if I can fix the
problem. Will report back. Ger "BubbaJim" wrote in message 66... Andy Cuffe wrote in : 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always As long as the back is open (I presume it is) look toward the rear, left or right, for a large transformer with two adjustment screws on it facing the rear. USING A PLASTIC TIP, turn the LOWER (screen) adjustment CCW and the thin lines will hopefully disappear. The upper adjustment is for focus. Hope this takes care of your problem. BubbaJim |
#6
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"Andy Cuffe" wrote in message
... On Mon, 8 Nov 2004 21:01:40 -0000, "Ger" wrote: Hi Group, My PC Monitor is a DELL Multiscan P991. About 2/3 years old. Just about useable in its present condition. It suffers from the following symptoms: 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always I have some electronics experience so taking the back off the monitor is no big problem. I know about the hi voltages etc etc. I am hoping that the above symptoms will be instantly recognisable by an expert as either some internal adjustment I can make or some component starting to fail and needing replacement. Any comments or advice would be very welcome please. Ger Did you run the "color restore" function in the menu? It usually fixes this problem. Andy Cuffe Andy Cuffe wins the biscuit - COLOUR RESTORE fixed the problem (after a WARM UP of about 35 minutes). But well worth the wait :-))) Thanks again to everyone Ger |
#7
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On Wed, 10 Nov 2004 09:10:26 GMT, BubbaJim
wrote: Andy Cuffe wrote in : 1. Screen is overly bright even after using brightness controls. Contrast is poor. 2. Icons are just a bit fuzzy 3. The 'flyback' lines are visible always As long as the back is open (I presume it is) look toward the rear, left or right, for a large transformer with two adjustment screws on it facing the rear. USING A PLASTIC TIP, turn the LOWER (screen) adjustment CCW and the thin lines will hopefully disappear. The upper adjustment is for focus. Hope this takes care of your problem. BubbaJim This monitor has no screen adjustment pot. It can only be adjusted through the service software. Both controls on the flyback of this monitor are for focus. Andy Cuffe |
#8
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