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| Thread ID: 30343 | 2003-02-16 22:32:00 | Monitors (again) | B.M. (505) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 121768 | 2003-02-16 22:32:00 | Further to previous posts, I have recently “doctored” a 15” Packard Bell Monitor and have it producing brilliant pictures. So, you may ask what’s the problem? Well, I’m curious to know what a “noise” is when it bounces back from sleep mode. Taking it from the beginning, the Monitor (and probably hard drive) have been powered down through inactivity by the power settings (win98 SE). Upon the movement of the mouse there is a clack (as opposed to a click), the screen comes on shimmers for a second, there is a click and all is well and up and running. Question 1: What is the click and clack? Question 2: What is the shimmering all about? The Monitor passes all Nokoia’s and Eric’s test patterns with flying colours except for the Screen Regulation where it probably marginally passes Nokia’s test, but fails Eric’s. Finally, the click and clack sound for all money like a relay, although possibly coming from a different location. (OK, what have I overcooked to get such a brilliant picture) :p |
B.M. (505) | ||
| 121769 | 2003-02-17 00:20:00 | The clack sounds almost like the laminations or the wiring coils (or the layers of insulating paper) of the EHT Transformer as it powers up from 0 volts to something around 25,000 volts and the click is probably as you say a relay. The shimmering could be the eht voltage fluctuating as it settles to its preset value after such a severe awakening. I haven't read the previous posts about your monitor but the doctoring could be an increase in the eht voltage which will increase picture brilliance but it will eventually fail as you are probably running the eht ccts at a higher percentage than the maker intended. I hope this has put some light on the problem. |
tandy (3109) | ||
| 121770 | 2003-02-17 00:51:00 | Thanks for that Tandy, Yes, I’m guilty of tweaking just about everything possible. I too have the feeling that I’ve got something on the edge, as the white is the whitest white I’ve ever seen on a monitor, and the black the blackest black. All the colours are correct, and the grey scale bang on, so if it hadn’t been for the clicks, clacks & shimmering upon wake-up I’d give it 10/10. Anyone tell me if Monitors have relays? I thought relays died of natural causes 20 years ago? |
B.M. (505) | ||
| 121771 | 2003-02-17 01:26:00 | Yes the click and clack will be a relay cutting in and yes monitors and TVs still use relays for switching What have you done to get brillient pix, well I guess you have reset the focus and increased the A1 voltage to he screen.... the little black knobs on he HV transformer at the rear |
OldEric (3062) | ||
| 121772 | 2003-02-17 01:30:00 | Oh, and the shimmering is just the pix coming into sync... nothing to worry about. It happens always when you first switch on, you just dont see it | OldEric (3062) | ||
| 121773 | 2003-02-17 02:28:00 | Your on to it Eric . I twiddled those little black knobs on the L . O . P . T . (Mind you no more than a 1/8 of a turn . ) along with ½ a dozen others . Glad to know my old ears are still tuned to relays . Quite surprised they still have them! Now, I’m not sure if E . ric, Eric & OldEric are one and the same people, but using E . rics black and white test pattern for screen regulation the height and width varies 3-4mm . Using Nokia’s black & white test pattern for screen regulation the height and width vary about 1-1 . 5mm . (about half) Question: How does one adjust screen regulation? (More to the point, what have I twiddled that I shouldn’t have?) :p |
B.M. (505) | ||
| 121774 | 2003-02-17 02:58:00 | What happens with your screen regulation.... does the pix increase in size when increasing brightness and/or contrast?? Could think of many reasons, did you tweak B+ probably located in the power section?? Keep your contrast at about 80% max and adjust your brightness to suit Nope not tied to any other Eric. E.ric is SE of me or was. Just OldEric with some spare time and work when I feel like it. |
OldEric (3062) | ||
| 121775 | 2003-02-17 04:11:00 | Sorry BM, but I think you are being fed a bum steer here. The click is a relay alright, but the shimmer is one of two things. Either it is the degaussing circuit operating (if so, the shimmer will be more of a shake and there will either be colour disturbances or dark patterns over the screen) or if it happens as the screen comes up to full brilliance and looks a bit like moving lines it is moire effect. This is caused by the interaction between the scanning lines of the raster and the dot-pitch of the shadowmask and is usually prominent on warm up as the scan expands to full screen. The EHT will not fluctuate, just rise steadily to operating voltage and the transformer is not likely to make a noise unless breaking down internally. Increasing EHT will only have a marginal effect on brilliance, but it will shrink your picture somewhat. I doubt that you have got into adjutments like that though. The most likely cause of an increase in brightness is a lift in the A1 voltage. If you turn this up too far you will see widely spaced very fine diagonal lines on the screen when the brightness is turned right down. If that happens, just back the A1 volts off a little further until the lines disappear then give it one more tweak lower for luck. Light blue touchpaper, retire to a safe distance, watch for flames:D Cheers Billy 8-{) :) |
Billy T (70) | ||
| 121776 | 2003-02-17 10:08:00 | Thanks Billy T, Wound up at the pub about 3pm so I’m a bit static’y! Just got home and Misses ain’t speaking so I’m down the dungeon . Ahhh! Not degaussing coil, as I know there isn’t one . (goes back to read Billy’s reply) Front panel controls both vertical & horizontal have plenty of margins and picture the correct size . Just turned brightness right down whilst typing this and got an ordinary type screen . No lines of any sort . A1 volts? Got me! (Struggles off to find somewhere to sleep) Thanks everybody . ;) Bob |
B.M. (505) | ||
| 121777 | 2003-02-17 17:54:00 | Well best of luck BM, hope you feel better this morning I looked at your previous posts and what E.ric said was correct, he is in the same tech field as I. Billy T in his post is right on the A1 set up count but the rest is not an issue here. Oh, and Billy I dont give bum steers, just tech advise or maybe I've been doing it all wrong all these years? OldEric |
OldEric (3062) | ||
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