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Discussion Starter · #1 ·
Hi.


I have got my fingers on an extra 1271,

but I think the AKB is disabled.

When brightness is 50 the colorbalance is OK.

When reducing brightness to less than 50 the image turns yellow'ish.

When I increase brightness the image turns blue'ish.


I've seached the manuals and the forum but am not sure how to do this...


Please help


Henrik
 

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Discussion Starter · #3 ·
Yes I know the text, but it doesn't say how to enable the AKB.......

Only how to adjust if the AKB is disabled.....


I'd like to re-enable the AKB.


Henrik
 

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It should be a small switch on one of the boards you take out of the back of the PJ (I'm not anywhere near a similar PJ or my docs - this is from memory).


I believe the manual shows this exactly, but if you take the board out of the back, not the input boards, it is located on it.


I can do it in my sleep, just can't describe it well right now because I have been working on Barcos, NECs, and EHomes lately.
 

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Discussion Starter · #5 ·
OK thank Keith.


Can anybody close in on the subject?

I only have part of the service manual and it doesn't show anything about the switch.

Where is this switch?


Henrik
 

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Discussion Starter · #7 ·
Quote:
Originally posted by kjelli
look at this pic : http://www.biggerhammer.net/mediaroo...oseup_pins.jpg


On the left side of the area where its pointet to Pin 1 and 4, just left from pin4, you can see 2 additional pins (white socket). On your PJ is there a "little thingy" shorting these 2 pins?
No, there is no shorting thingy on those pins......


Henrik
 

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Discussion Starter · #8 ·
So, can anybody help me?


How do I re-enable the AKB????


Henrik
 

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1. Open the hood

2. Remove the three screws on the upper part of the connector panel frame to remove.

3. Remove the two screws on the upps cover of the connector panel and remove the cover.

4. Pull the BA board out toward you and set the SW1: Dynamic PIC SW on the board to ON/OFF (as desired)

5. Replace the parts following steps 4 to 1 in reverse.


Straight out of the manual. It has pictures if you want to see them.
 

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Discussion Starter · #10 ·
Thank you!!


But that part of the installation manual never mentions ANYTHING about AKB,

or lines above the image.....

So how was I to know?


Anyway the switch was in the off position ..... the factory position....


So, I have a 1271 that goes yellow at brightness down and blue at brightness up.

The tape on top of the screen adjustments is broken (so they are probably messed with).

The Dynamic PIC SW is in the "off" position.

I known from people working in the company that owned the PJ before,

that they only hired professionals to adjust the PJ.


What will cause this behavior?

AND most importantly how do I fix it?


I hope you or anybody out there can help me...


Henrik
 

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The pic SW1 is to enable/disable the AKB is news to me. (But that does not mean it's not correct). I thought the only way to disable the AKB was to short those 2 pins mentioned earlier.


Sounds like you need to readjust the G2, or atleast check the voltage. When I got mine 1271 I checked the G2 and the red was almost up at 10V.

How to check the G2 voltage is discussed in many other threads here, do a search.


You have checked that the color temp is at 6500K etc?. None of the tubes have excessive wear etc?


Kjell
 

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I agree. Get a multimeter and set the G2 values, then balance it from there. Almost all of the Sony 12XX units that have come through my workshop have had the picture pots messed with.
 

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Discussion Starter · #13 ·
Thanks you guys.


I will try G2 adjustment then.

I never have had a need for that on my primary 1271.

But that never had it's screens messed with, so....


Henrik
 

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The AKB enable and disable is ONLY by shorting the pins with the supplied jumper on the rear little PCB ( I cant remember the number). If the jumper is not on the pin strip the AKB is already enabled.


That Dynamic picture switch only works on Video signals, A bit pointless actually.


Your G2 is stuffed up thats why the blacks are wrong
 

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Discussion Starter · #15 ·
So, then thats cleared out.


Thank you Graham.

I will try to correct the G2's.

I guess that is done by resetting the bias and gain to factory default,

and adjusting the screens to something like 4 V.


Henrik
 

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Just do the G2 adjust proceedure and don't touch the bias and gain till later. They are already more than likely set to factory defaults unless someone fiddled them. :)
 

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Discussion Starter · #17 ·
OK, thanks


Henrik
 
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