 Posted: Sat Aug 17, 2013 9:47 am Post subject: |
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| The service manual should help a lot, but I suspect it's not really as complete as it should be, without enough descriptions and info to fully understand everything without getting some help elsewhere. | |
| Posted: Wed Aug 14, 2013 4:10 pm Post subject: Just a heads up |
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| Hi,
I'm just dropping a note to confirm that since that little intervention with the G2 adjustment, the tv has stayed on and the issue (so far) has not returned. The one thing to note is that turning it counterclockwise didn't do anything, but then a little bit clockwise did the trick. I hope this will be of use to some other unfortunate soul out there who would end up with the same issue. Thanks for all the help |
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| Posted: Mon Aug 12, 2013 12:50 pm Post subject: |
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| I figured what the heck, it doesn't cost anything to try turning that adjustment the other way, and just in case, I made that small adjustment while it was turned on. And for the moment, it may have worked, as the tv is still turned on (for now).
If this stays that way, can I assume the problem went away? This is such a tiny thing to do to fix this. I'm glad I don't need to change parts, as my eyesight has gone down a lot in the past few years and my hands are no longer as steady as they used to be as well, so soldering has become more difficult for me nowdays. I hope this issue won't come back again to haunt me any time soon, I have enough "devices" that are down right now, a laptop died from overheating, a washing machine stopped working as well and a refrigerator is ready to give up and we can't afford to replace any of this. Thanks for the hints and help |
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| Posted: Mon Aug 12, 2013 12:19 pm Post subject: |
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Ok cool, since I wouldn't have access to such equipment.
Fine with me, if I can get this fixed without using that.
Ok then, that's what I did, and I think the tv stays on for about 35-40secs now before it shuts off. Should I try turning that knob in the other direction then? |
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| Posted: Mon Aug 12, 2013 12:01 pm Post subject: |
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| Dot gen and 170 Volt supply are external to set. You will NOT be performing ALL steps.
Stay OUT of Service Menus!!! 1/4 turn (presuming 90 degrees) (in either direction) is about 75 degrees of rotation MORE than you'll need. Actually the pot will only have approximately 270 degrees TOTAL, and you should only need to rotate it approximately 15 degrees from your starting point. |
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| Posted: Mon Aug 12, 2013 11:56 am Post subject: |
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| Some slight improvement that may help move forward. Since that little adjustment of a 1/4 turn on that RV5376 allowed the tv to stay on a tiny bit longer, I was able using that remote RM-947 on hand to reach the service menu. However it didn't stay on long enough for me to go anywhere further, as the tv shut off right after it.
Apparently using the RM-947 remote instead of the RM-887 seems to also work and allow reaching the service menu, at least we have that. I managed to issue the "reset devices" command right before it shut off, but that doesn't seem to have had any effect. Am I getting a tiny bit closer? |
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| Posted: Mon Aug 12, 2013 11:45 am Post subject: |
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I get it now, it's that heading "3-3. Focus, Screen (G2) Adjustment" on page 24 that induced me in thinking that G2 had something to do with that adjustment on the flyback, especially since that's what we see just below. And that's also where I noticed that the second adjustment below the focus was "no function"...
I have a TNT box, so that's how we receive tv, and that's what I can use.
Those are the steps there for that RV5376 adjustment, so I assume they all need to be taken to proceed, so I'm wondering now if that pattern/dot gen isn't some built-in maintenance feature from some maintenance menu on the tv. And perhaps then that "external" 170V DC power supply is built-in too.
I located that RV5376, and just in case, gave it a 1/4 turn counterclockwise before turning on the tv, just in case this would make a change that would prevent that issue, but although it seems now to take a little bit more than 30secs before the tv turns itself off, it still does. One other thing, I read a bit further in that manual about the remote commander RM-887 for this model, but the one I have is RM-947, which works fine for all usual operations but would it also work for service? I tried earlier to enter that service mode from that side panel, holding those 2 buttons as described, but nothing happened and the tv turns off before I can see anything.
That's what I figured when I read "no function". I was only confused into thinking that focus was the G2 adjustment. If I can't go into service mode and the tv doesn't stay on long enough for me to do anything, then what else can be done? Thanks |
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| Posted: Mon Aug 12, 2013 10:25 am Post subject: |
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G2 is actually NEITHER of those two.
Set with antenna tuned to a station will do, or whatever you were using to obtain a pix and sound for about 30 sec.
"1" is the dot gen - "3" is the 170 power supply - NEITHER ONE WAS "I" quoting! Work faster! >>>Why don't you try unplugging the CRT circuit board from the neck of the tube so you can get some decent light on it to locate the potentiometers on the "C" board. <<< Notice that this is a statement - NOT a question. Page 22 has a decent picture of the "C" board. DON'T confuse the H. Stat (RV5375) with the G2 (RV5376). The Flyback is located on the "D" board and actually contains ONLY the FOCUS control (the other is a "dummy").
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| Posted: Mon Aug 12, 2013 9:24 am Post subject: |
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I vacuumed up all that black dust so I could put my hands in there without being very sticky black and at least see the parts. So I can see those 2 adjustments better on the flyback now. So if I get it right, the G2 actually isn't one adjustment but rather both of them on the flyback, including that one that says "no function" and I suppose that is the one that needs to be changed to (hopefully) resolve this issue. I will try that. In any case, those adjustments can always be re-tweaked later if I can't put them back exactly the way they were, and besides, the adjustments probably needed re-adjustments anyway. The main problem is that I can't get any picture to watch, since it goes off after 30secs, so what is says in 4. can't be done, and what I surely can't do from 4. is to have a dot pattern generator and certainly no 170V DC external power supply to make such adjustments. I can only do it while the tv is off without any feedback from the tv itself. So perhaps that may not help much. I will try again later on, but in case it doesn't work, what can be done without being able to keep a picture on the screen with the tv on? Thanks |
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| Posted: Sun Aug 11, 2013 11:45 pm Post subject: |
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| I usually just take a magic marker and draw a line across the control - that is across the movable part and onto the stationary part so that to put back you just match the marks into a straight line.
Page 24 G2 adjustment [RV5376] 4. Whilst watching the picture, adjust the G2 control RV5376 [SCREEN] located on the C Board to the point just before the flyback return lines disappear. C Board Page 34 - G2 It's on the printed wiring board on the pointy part of the picture tube (directly opposite the viewing surface). Service manuals are written to be used by persons with some electronic learning / training ('technicians'). They give service codes to lead technicians to the approximate area, not necessarily the actual bad part or cause. As far as how long fine adjusting G2 control will last, that depends on how fast the picture tube is aging, which is the actual cause of most AKB shutdowns. |
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