CurtPalme.com Home Theater Forum

[CasetheCorvetteman]

Im not sure that id swap the yokes...

[redfox001]

It is a possible explanation. I think the TS wrote that the cine 8 fall or something. When these magnets in a yoke get a hit they demagnetise all three. So it is a possible explanation and something to try on one tube. Might also be that the yoke just does not work with the tube.

[redfox001]

You might be right. It seems these yokes focus to much. Even at 0 when the beam should be underfocussed it is still overfocussed. Even when moven to the bell where underfocus should get more it is not enough.

Seems like the magnets are to strong or the focus board is wrong. But the focus board was tried in the 808 and was ok?

Than still the yokes are all that is left.

I still would disconnect the focus cable as that is the simplest way to make sure the magnets are allright. There is no risk for the tube and the cine 8 should not give an error with the focus cable disconnected. Just be sure you do not disconnect the scanwires. Than you would get a scanfail.

[CasetheCorvetteman]

Disconnection of the focus yokes while the set is on is probably not a good move, im sure it has been put to me before that doing so on an NEC can damage the focus board, so i wouldnt do it on any set, disconect the feed to the focus board or the power to it, or both, but i wouldnt run it unloaded.

What the next step should be is remove the splitter from the blury Cine 8 and install it into the known working 808 for testing. If it works fine, we will know its not the cause.

[redfox001]

[CasetheCorvetteman]

Oh ok... So youre an expert then... My appologies.

Why is it i have a Barco splitter here that causes a serious focus issue???

[gjaky]

Case, I also pushed/pulled the focus and convegrence coils in my both NECs while it was working without any issues.

[CasetheCorvetteman]

You may have indeed, but i certainly wouldnt!!

[redfox001]

It is an easy thing to try in a minute than go for the splitter that is my opinion.

[macgyver655]

A focus board does not have any surge protection on its output lines and therefore can be damaged if a connection is altered while the unit is powered up.

A splitter has resistors built in for power dissipation and arc suppression. A change in value of a resistor can cause a reduced HV on a line which would show onscreen as a focus issue.

[dentree]

This war of words is certainly confusing to me at present, so I shall watch it play out here, unless there is a definitive argument from Curt himself as to what direction to go in at this juncture,
having said all that I find it fascinating to read the various views you guys have on this subject, but I am extremely timid about anything major, as I am sure you are all aware the old saying "A little knowledge is dangerous" well that's me at the moment........but keep it coming !!

[redfox001]

To stop the confusion. Try the splitter as it is a possible cause.


It seems we all agree on disconnecting the focus yokes before you switch on is not a danger but I still advise exchanging the focus coil as a second option. But to be honest I think the magnets would have to be to strong and that is unlikely so try the splitter.

[redfox001]

By the way can you handle soldering? You need to solder a small wire. Not very difficult but it has to make a good connection.

[dentree]

Well boy's..just when you thought you might be rid of me, I am back with the results of the attempts to date, but first I hope that all of you have had a happy and safe Christmas and New Year (or Holiday for those who may not celebrate the season)

First of all I will go thought what I have done to date.

1. Fixed the SMPS board (fuse), everything now OK all GREEN on the SMPS board.

2. Have swapped the SMPS boards between the BG 808 and the CINE 8, both perform OK in either machine. (it takes a little time to swap them around as I only have the one QUAD to share between the two at present).

3. I have managed to identify the GREEN gun (for which I indicated I have no info on )

RED: BARCO P16LNP07RJA
GREEN: PANASONIC P16LNP07HKA
BLUE: PANASONIC P16LNP07BMB

4. The voltage on both SMPS boards are reading 17.2 volts

5. The Yoke have been checked, and they are all hard up to the bells.

6. i have noticed that the focus coils(which are hard up to the focus yokes as previously mentioned,
rotating then around the tube neck does not actually do anything, they do not have any influence on the crosshatch displayed) they neither affect the focus nor the position of the image. (so don't know the answer to that one)

7. I have changed the splitters between the two machine and there is absolutely no difference between either if them.

8. I have swapped the two convergence trays between the the two machines, (there is no difference there either.

So bonnie lads, basically I am back to square one with the focus issue still can only get (reasonable) focus at/or around ZERO on all 3 guns, the only thing it suggests to me is that whatever it is is common to all 3 guns, so it's obviously not the guns there must be something else which is common to all 3, this is where the ball is chucked back into your courts.

9. I will post a few pictures of the mess I am in currently, and a few shots under the hood!

Hope you all have not run for the hills !

Regards to all,
Trevor

[dentree]

Splitter swap

[dentree]

BLUE

[dentree]

GREEN

[dentree]

RED

[dentree]

RED/GREEN

[dentree]

GREEN/BLUE