[Curt Palme]

I posted a while back about a strange anomaly that I had in an XG where the bottom left corner on the red tube would not converge. In fact, on the last two 'fine' point adjustments, the red didn't move at all in a V direction.


Changing the C board did nothing, neither did changing the system and wave boards.


I finally did a hard reset, and everything came back just fine.


Today I worked on an XG 135LC that had corner focus that was nonexistent. BAd thing was, the set worked in the shop fine, I flipped the image at the customers home (locally, luckily!) and the set looked horrible. After fighting with it for an hour, I took it back down and back to the shop.


What was strange is that the R and G tubes were original NEC's, the blue was a VDC. When I went into the astig adjustment, most of hte dots were round, but changed in overall size from the middle to the top and bottom, nothing was uniform.


After changing the A and C output boards and still getting no results, I did another hard reset.


Voila, everything dropped into place.


The good thing is, a hard reset seems to cure a nuber of strange and obscure problems, and is the fastest way to reset all convergence memories to 0. The bad thing is, the set almost always needs a full color balance, and that can take 4 hours like it did today. End result was a perfect working set.


I'm NOT going to post how to do a hard reset, if you have never done it before, then don't anyways. For those that have, try doing one the next time you have an XG that just looks 'off'.


Curt

 

[WanMan]

Dear god, that's not a good sign. Curious, couldn't you use the NEC software to backup configurations and then reset and restore?

 

[gierig2]

Hello,


how do you dit the hardware reset?


Tx


Robert

 

[Chuchuf]

Wanman, you hit the nail on the head.


Or you could write down all the "reference" settings (which are global), restore them after the initialization manually, and only have to deal with the Kelvin settings (which are per memory) to get grey scale correct for each input.


Doing a hard reset is not for the average person on an NEC and can create more problems than it solves. For someone who works on NEC all the time it is a good tool to use. So don't ask how to do this as no one here will tell you how.


Terry

 

[dokworm]

Well someone *might* tell us how, then we can all do it, stuff it up, and pay you guys to come fix it

 

[Chuchuf]

But then they would have to shoot you!!!


Terry

 

[benny]

Quote:

Originally posted by WanMan .... couldn't you use the NEC software to backup configurations and then reset and restore?

Has anyone had success using the NEC control program to backup and then restore AFTER a hard EEPROM reset?


I have a few small areas of misconvergence which can't be isolated without affecting another area, and I've been wondering for a while whether this is because of the cumulative effects of past memory settings. It would save a lot of effort if I could get each currently used memory setting close to where they are now after a restore, but it's no real drama I guess if I have to go back to scratch.


Resetting the greyscale tracking doesn't phase me one iota either, and it's probably time I rechecked that aspect anyway since my tubes now have about 300 odd hours on them.


Hmmmm .... I'll think about this one for a while methinks before jumping in.


Cheers


Russ

 

[Chuchuf]

Russ,


I do it on a regular basis with no issues.


Terry

 

[benny]

Thanks Terry ... most reassurring to get your feedback.


Cheers


Russ

 

[WanMan]

While I can understand that no reseller wants a bunch of user-broken NEC's to hit the market, I cannot help but think of the advantages of getting another one at a deep discount.


BTW, has anyone ever tried using the software from one unit on another unit to dial-in, say, 90% of the settings needed, or is it the experience that practically every dang unit is so different (different set of tubes, for instance) that its not worth the attempt to save an hour or so on setup?


Also, when someone gets the unit fully calibrated and backs up their settings they may also wish to remember the CRT's condition will change over time as you wear the phosphor out. This isn't a bad thing, but just one that needs to be recognized if restoring a unit with a backup config that is 'dated'.

 

[Chuchuf]

The backup may be a bit dated, but it is still a great starting point.


Terry

 

[deronmoped]

Benny


Is that with your 10PG? I have some convergence problems that I have to correct with point, which I should not have to use for them. I did a reset to begin with, but I do not know if it was a hard reset. One thing I found out was if you use too much bow that will cause problems with point.


Also is there information in the manuals you sent me on a hard reset?


Thanks, Deron.

 

[Tinman]

Guys, to do a hard reset is very simple. Step one: Get a service manual.

Step two: READ the service manual.

Step three: Understand what it is you are doing. Yes, the hard reset can clear up some weird problems, but as discussed in many other NEC threads it is a last resort measure. If there IS a problem with the CPU board, a hard reset can cause the projector to die. Sometimes the stored parameters are all that keeps it working. I strongly suggest that anyone who wants to get into a projector pays the $10 bucks and downloads the full service manual. You pretty much need it.


Curt, we used to do this even on modern camcorders. You would be surprised that the eeprom in a camcorder can just become corrupt and you SWEAR the problem is a busted IC. But it's not.....


Marc

 

[Doug Baisey]

Guys,

This is what I have found to be true also. I only do this procedure if I have another one (system board) with me and caution the customer that its a possibility.


Sometimes you have no choice if you tried everything else by deleting each line and defaults.


I hold my breath every time I'm in that situation and I have more then a few bad system boards from this. Usually will not restart at all.


When it does work you have a fresh start like Curt found, it sounds like the polarity change and or 'astig output' didnt reset from the settings mode when he changed it but did clear when he did the init. eprom. Doug

 

[stefuel]

I had some line distortion that I could not eliminate. I gave it a case of artificial amnesia (hard reset) to solve it and it did.


Chip

 

[RoBro]

Can you explain what exactly a hard reset does and how it can fail?

I think it should erase all the eeproms and load back into them the original information stored in the eproms.

So there might be a problem if the eproms have lost information.

Couldn't one just take the eproms of a good system board, put it into the defective one, copy the information into the eeprom by hard reset, and put the eproms back into the board they came from?

Roland

P.S.:

all these e ans ee...

 

[benny]

Quote:

Originally posted by deronmoped Is that with your 10PG?

G'day Deron,


I am not aware of ANY 10PG's being sold down here and none of the fellow aussie CRT owners have mentioned the existence of that model here. I sure would like to see one though to understand what all the positive reviews have been about.


The small misconvergence issues I am seeing ( and they are for the most part unobtrusive ) are with my remaining XG. I could correct them with point, but that would be a bit tedious. I'm thinking there may be some underlying reason why there are a few small areas that don't behave the same across the 3 colours. I've reset the point values but that hasn't had any overall effect.

Quote:

Originally posted by deronmoped Also is there information in the manuals you sent me on a hard reset?

Check your PM.


Cheers


Russ

 

[dokworm]

We had a 10PG on the ceiling at our North Ryde office when I was there in 2000. Came straight from our Sanfrancisco office to Sydney.

It is the only one I have ever seen, and was unfortunately calibrated quite badly, and mainly had VHS run through it, so I never noticed the quality being anything special.

And yeah I've already checked, it's not there anymore. Apparently they sold it to a (clever) employee.

 

[jrobbo]

Quote:

Originally posted by Tinman Guys, to do a hard reset is very simple. Step one: Get a service manual. Step two: READ the service manual. Step three: Understand what it is you are doing. Yes, the hard reset can clear up some weird problems, but as discussed in many other NEC threads it is a last resort measure. If there IS a problem with the CPU board, a hard reset can cause the projector to die. Sometimes the stored parameters are all that keeps it working. I strongly suggest that anyone who wants to get into a projector pays the $10 bucks and downloads the full service manual. You pretty much need it. Curt, we used to do this even on modern camcorders. You would be surprised that the eeprom in a camcorder can just become corrupt and you SWEAR the problem is a busted IC. But it's not..... Marc

I agree 100% that if you are going to do a hard reset, that you should at least own and understand the service manual, but this statement needs clarification. The service manual does not tell you how to do a hard reset, that function is hidden away deeper than the service manual will take you.


EDIT: I've just been informed that the service manual for the 1351 does describe a procedure for resetting the EEPROM, but that procedure is not described in the service manual for the 1350. Interestingly, the procedure in the 1351 manual is very different from the one I was talking about. I wonder if the 1351 procedure will work on the 1350? I'll give it a try next weekend, and let you know.


Regards


John

 

[WanMan]

No chit! I think the idea behind hiding the code is to keep it in the hands of professional NEC service technicians.


Question: Could knowing the code create a potential harm in that a unit cannot be made operable?