Can't Calibrate Rejuvenator For Swapped Tube...

[MKFan4Life]

Back in April I used my B&K 467 rejuvenator (just then bought on Ebay), to try to bring some life back into the 1992 Zenith G-A63ADG25X tube for my Mortal Kombat 1 machine.  Well, after following all the instructions from the PDF setup file I obtained from the B&K website, I was able to successfully calibrate the rejuvenator to the tube and follow through with little trouble.  All went as planned, but the poor blue gun was just too far gone to save.  The other 2 guns did, however, end up with much improved emissions.  This left the entire screen greenish from the low blue output.

Well, I just bought a used replacement tube from a fellow about an hour away who runs an arcade repair/sale shop.  It was a reasonably close matching tube I imagine, a 1995 WG A63AGD01X complete with the yoke.  He told me on the phone it didn't appear to have any burn-in and he had recently had it going and the colors were good. 

While out in the sunlight loading it, I did notice "CREDITS" lightly burned in at the center bottom of the screen, but inside the building, even with bright lights it was not visible.  Later at home, I noticed the yoke was missing one of the shims at the top center of the neck, but it didn't appear to be causing the yoke to move around any.  Also noticed the plastic encasing the pins on the neck was cracked, but this too, seemed a non-deal-breaker.

Then, after performing the chassis swap from the old tube (which proved relatively uneventful for it being my first!), I installed the new setup in the cab and powered it on.  After getting into the monitor tests in the game's setup, I adjusted the colors a little, and had to carefully adjust the horizontal width coil as the image was running off both the left and right sides.  This went well, but the vertical size at max was leaving a slight black bar both on top and bottom of the screen.  Figured I could live with that for now.

But the COLORS!  No matter what I did, I was having similar issues with this swapped tube as I had with the original one before rejuvenating that one.  Dim screen and weak colors that simply tried to bloom and bleed if you started to pump up the gains.  I thought, awe man, have to try the rejuvenator on this one, too, and hope for better results.  Well, that has proved impossible, for the emissions on all 3 guns are so low apparently, that I can't even get the rejuvenator calibrated.

With the heater voltage set correctly to 6.3V and the G1 set to 50V, I can't get the G2's to budge off of ZERO!  I even set the G2 from Normal to High and the needles for each gun won't budge a bit from ZERO to get the needle up one division on the meter.  So with all 3 of the adjustment knobs set to the farthest clockwise position and the G2 selector on High, I went ahead into the test mode to monitor the emissions, and they sat flat on ZERO.

I went ahead and tried the Clean/Balance process (even without getting the G2's set), hoping the emissions would start improving, but nothing changed.  (I had to blindly hold the buttons for a second or two while attempting this, because the needle never went up and back down.)

I tried this 3 separate times, from setup to Clean/Balance just to make sure I was doing it correctly, and the same results appeared each time.  I kept disconnecting the #23 adapter each time thinking maybe it wasn't plugged onto the neck of the tube well, but it was.

None of the short lights ever glowed during the tests, but when testing the Focus, the light never glowed like it should.  (Since I am new to this, this puzzled me, because the focus adjustment on the flyback works fine and the tube has good focus.)  The PDF setup file says an open focus connection can't be repaired.  The Tracking and Life tests could not be performed as the needles stayed at ZERO.

Can anyone tell me if this is simply a WAY TOO FAR GONE tube, or if they have seen this happen before?  I figured the guns would show in the bad region upon using the Tester/Rejuvenator since the other tube's guns did, but I never thought they would be hopelessly bottomed out.

(I called the fellow and, although puzzled since he remembers testing the colors recently on this tube, he agreed to swap me another one when he can pull one from a cab that needs the chassis rebuilt within the next week.)

[Ken Layton]

An old trick for a tube like this is to set the heater voltage from 6.3 volts up to about 8 volts and then do your rejuvenation.

[lilshawn]

An old trick for a tube like this is to set the heater voltage from 6.3 volts up to about 8 volts and then do your rejuvenation.

2nd'ed

the hotter heater helps pump out more electrons from the guns.... don't go crazy though you'll burn it out.

sometimes turning up the G1 voltage a little helps get a decent read too.

[MKFan4Life]

What would be safe to pump the G1 up to?  The guy has offered to pull another one from a cab he needs to work on the chassis of, so I'd hate to damage it beyond use.  But how do I even know what I am doing since the needles aren't moving when trying to adjust the G2's up one division, and they don't move up and back down when doing the Clean/Balance (and probably a full rejuvenate)

Thanks for the suggestions.

[qrz]

An old trick for a tube like this is to set the heater voltage from 6.3 volts up to about 8 volts and then do your rejuvenation.

yes, and Sencore units do that as part of the rejuve process  (cr70 , cr7000)
can be found on ebay for much less than i pd new ....

[lilshawn]

What would be safe to pump the G1 up to?  The guy has offered to pull another one from a cab he needs to work on the chassis of, so I'd hate to damage it beyond use.  But how do I even know what I am doing since the needles aren't moving when trying to adjust the G2's up one division, and they don't move up and back down when doing the Clean/Balance (and probably a full rejuvenate)

Thanks for the suggestions.

ive gone as high as 80v on tube i don't care about to get a reading...having said that, usually if i'm pulling out the rejuvenator, i'ts a list ditch effort before tossing it in the dumpster. so i wouldn't go crazy on one i planned on keeping.

what i do is set the RGB at max and turn up the G1 up a bit and see when it starts to read...then switch it back to the G1 voltage reading and see what it at. if it's not too high (use your own discretion) i leave it there and continue testing/rejuvenating  but if it's way up there i just toss the tube.

but usually ramping up the heater is enough to get a better read.

[Rickn]

I may have mis-read or missed something???

Seems to me you got a second/other tube from someone else, swapped the bord and had the same problem. Sorry if I misunderstood, bur seems to me if that is the case? It is a board problem -not tube?

[MKFan4Life]

I may have mis-read or missed something???

Seems to me you got a second/other tube from someone else, swapped the bord and had the same problem. Sorry if I misunderstood, bur seems to me if that is the case? It is a board problem -not tube?

First was a Zenith tube and WG-7197 chassis which came in my MK1 cab.  When I got it, it was dim/washed-out looking and any attempts to adjust colors led to blooming/bleeding of the colors.  I did a full recap with kit from Bob Roberts.  Looked a bit better focused, but that's about all that changed. 

After buying a rejuvenator off of Ebay (B&K 467 for $75 shipped) and trying it out for my first time on the Zenith tube, it showed all guns in the BAD region.  After rejuvenation, I was able to get Red and Green guns way back up into the GOOD region, but poor Blue actually got WORSE and stayed in the BAD.  Upon firing it up with the same chassis, I did indeed notice better Reds and Greens, but the weak Blue emissions left the screen looking all greenish/yellowish unless I throttled the more powerful Red and Green gains down a good bit... but then, the screen went back to looking too dim.  The rejuvenation DID brighten the screen (brighter Red and Green output), but it did no good since the Blue was too weak to keep up.

Now THIS second tube I bought used from a fellow an hour away, shows NO emissions at ALL when connected to the rejuvenator, and of course, the screen is WAY too dim.  I would think about it being a chassis problem also, if it weren't for the B&K 467 telling on the tube.  I guess I COULD go through the hassle of removing my Hantarex Polo chassis from the tube in my MK2 and trying it out with this WG chassis, but after a full cap kit (which fixed SEVERAL issues!) on the POLO chassis, that combo is looking so beautiful, I don't want to muck with it!

Thanks kindly for all the pointers guys!  I likely won't stress the tube which I bought from the fellow since he has offered to swap me another one for it back, but if all else fails, I'll try the techniques on the tube I end up with or the old one I am trying to replace.  A company on Ebay is offering BRAND NEW replacement tubes (they give you a price and shipping quote after you contact them with model), and for the exact same model I am replacing they quoted me about $65 for the tube and $85 for shipping.  $150 total for a Brand New tube doesn't sound unreasonable, but I didn't want to wait and then possibly deal with damage during shipping.  Might end up going that route before it is over, though.