VOGONS


First post, by gmaverick2k

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I'm trying to service some LG flatrons I have got my hands on. Recently I've been able to service a trinitron successfully using WinDAS and a cheap usb 232 ttl adapter + dupont cables and winXP (similar to how Adrians digital basement has done it: https://youtu.be/Lt1NtRH4BOg?si=LxI5LPDCiQ4RKeQ5)

Opening up the LG 776FM flatron, i though I would be able to adjust the g2 brightness on the flyback transformer, it's missing. looking at the service guide, it looks like they use the programmable EEPROM thing that sony do. has anyone a calibrated LG crt monitors in the past similar to how sony do theirs?

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"What's all this racket going on up here, son? You watchin' yer girl cartoons again?"

Reply 1 of 8, by gmaverick2k

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Essentially what I'm asking is has anyone serviced one before using cheap off the shelf components like the Sony win DAS solution. I wish this information was accessible in the past as I've had trinitrons that could have been serviced but this time I have four LG flatrons/studio works with no lg specific guides online or on YouTube

"What's all this racket going on up here, son? You watchin' yer girl cartoons again?"

Reply 3 of 8, by gmaverick2k

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oldhighgerman wrote on 2024-08-08, 23:46:

Other then the trimpots that stick out of the back once the case is off, I wouldn't touch anything w/o a manual.

Pretty much. Took case cover off, didn't see G2 adjust pot, took pics and put cover back on. Sharpness doesn't need adjusting so left that alone

"What's all this racket going on up here, son? You watchin' yer girl cartoons again?"

Reply 4 of 8, by gmaverick2k

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Forgot to mention had Spyder 4 elite for calibration of Trinitron. Have a cheap used xrite 1i display pro coming in the post. Just really impressed with Sony foresight in being able to bring the Trinitron back to near perfect geometry and black levels and colours using digital software

"What's all this racket going on up here, son? You watchin' yer girl cartoons again?"

Reply 5 of 8, by zuldan

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gmaverick2k wrote on 2024-08-09, 04:37:
oldhighgerman wrote on 2024-08-08, 23:46:

Other then the trimpots that stick out of the back once the case is off, I wouldn't touch anything w/o a manual.

Pretty much. Took case cover off, didn't see G2 adjust pot, took pics and put cover back on. Sharpness doesn't need adjusting so left that alone

I have an 15” SVGA IBM monitor that is really blurry. Are you saying this is fixable by opening the monitors case and adjust something? I was about to chuck it in the bin.

Reply 7 of 8, by momaka

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I don't know if LG CRT monitors are / may be related to Samsung CRT monitors or not. But if they are, all I can tell you is that I've read in Samsung CRT SM's that they use a software called "SoftJIG". It's essentially the equivalent of what WinDAS is for Trinitrons, but I never used it... and don't think I have a copy either(??) (Will check on that.) I did do some digging into that topic a long time ago, though, since I have a Samsung SyncMaster 955DF that's a little too bright (too much G2), though not terrible like a 21" Trinitron. Was going to mess with it, but then figured I could use the brighter monitor for online gaming, as I already have another 19" CRT that has pretty much perfect colors and brightness which I use for "cinematic effects" gaming.

If there is no software to adjust the G2, you can try to trace back (either in the SM or on the actual monitor PCB) where / to what chip the G2 gives feedback about its voltage value and try to "fool" that chip / circuit with some resistor dividers. Back before the guides for Sony WinDAS became popular online, I remember reading on quite a few places where people used this trick to lower the G2 on their Sony Trinitron CRT.

zuldan wrote on 2024-08-09, 11:07:

I have an 15” SVGA IBM monitor that is really blurry. Are you saying this is fixable by opening the monitors case and adjust something? I was about to chuck it in the bin.

Possibly.
It might just need a G1 (Focus) adjustment through the pot on the flyback transformer (some monitors have two Focus knobs... but that's usually the larger, more "modern" CRTs.) Or it might need a recap (rather involved job).
Whatever the case, advisable not to just "chuck it in the bin", if possible. If you don't care to fix it, you can always put it up on your local Craigslist (or equivalent site) as a "free, you pick up". That's how I got most of my CRTs back in the day when people were getting rid of them left and right. And that's also how I've given away a number of items before. So long as you're not too far out "in the middle of nowhere", this method usually works for getting rid of stuff.