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[brad808]

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[lilshawn]

check for heater voltage at pin 6 on the p903 connector on the neck board. you should have somewhere around 6 volts there. no volts means there's a power problem someplace up stream in the SMPS. power on the monitor and listen to hear if you can hear any clicking. if it's clicking the SMPS output is shorted or overloaded. it's probably best to change out all the caps on the output side of the SMPS anyway.

C124, 129,118,119,117,120,130,116

if it's still clicking maybe a shorted Q402 or shorted IC301. if it's not clicking check your SMPS voltage outputs on the banded side of the diodes... D106,107,109 and the resistor D130.

D106 volts will vary depending on how the monitor is set but should be about 100v

D109 this is your B+ voltage, it could be anywhere north 135v DC so use caution when testing. use alligator clips if you can.

D107 should be around 25-27 volts. it's kinda random i've found. but definitely no lower than 14.5 volts, as it runs into a 7812 regulator and feeds the 12 volt supply and it will drop out if the voltage goes too low.

R130 is the 12 volt supply

also check header connector P201, on pin 6, it should have 12v there.

wherever you have a low voltage, there is where you should check for more problems.

[brad808]

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[grantspain]

looks like the something arcing in the neck,maybe the neck is cracked

[brad808]

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[grantspain]

new tube required i'm afraid
the deflection yoke does not looked to be the bonded type so if you can find the same size/type tube from a tv you could do a yoke swap

[lilshawn]

yep, sorry it's gonzo. there is enough atmosphere in there now to throw everything off. it doesn't take much. it's definitely arcing in there though.

 i agree, remove the yoke and find a donor tube. to remove the yoke, put a dot of paint or something on top to remind you which way is up on it and just loosen off the metal clamp right at the end. with some gentle turning back and forth you should be able to work it loose and it will slide right off the neck.

Be warned, the plastic that makes these yokes up is quite brittle and can snap quite easily. if it won't budge, you may have to take off the metal camp entirely and use a thin shim of plastic under each the "fingers" (you'll see) to get it loose. they often put fabric tape under there to keep things from moving and it can glue down the yoke.

take the tube number off the tube (A68E bla bla bla bla bla whatever) as long as you can find one in the same series, it should be okay to swap. (for example A68ELA123G456 would be probably similar enough to A68ELX123R8123 to work you will have to double check the pin count on the end of the neck.)

to find a tube, take a couple long phillips screwdrivers, a flashlight and a tape measure and toss them in your car. if you happen across a TV someone is tossing out or you are at the sally anne/value village/other thrift store and see a sizeable tube, measure it up. make sure it matches the shape of the old tube (regular "round" vs flat or near flat tube) if it's the size you are looking for, peel open the back (if it's trash) or try and look in with the flashlight the back of the tube and see if the tube number is close enough to what you are looking for.

then it's just a matter of sripping off the old yoke and putting your rescued yoke onto it and aligning things back up.

[brad808]

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[grantspain]

i can't see the neck pins on either photo but unless one is dual focus and one is single focus it should work just fine

 post photos of each crt neck pinout and the chassis crt socket

[brad808]

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[lilshawn]

the single pin all by itself sequestered in it's own little box is the focus. if the donor tube has 2 pins in there, it's dual focus. the little plastic bit should be attached to the tube. it's mainly to help line things up during assembly and not expressly required... but if the tube gets dirty or damp, the focus voltage can leak out of the socket without it. (it's alot harder for volts to zig zag through the walls of the box)

the flyback could be dual focus, but sometimes they will just reuse a case for a different model to save on tooling costs for a new mould for the plastic. but likely even cheaper still.... one of the leads has just been removed. if you look at the top you might see a bit of heat shrink tube over it.

i'd like to see a tube a little closer. A68KV------ at least.

the number scheme goes like this:

A68KVL74X03

A: tube quality from best to worst A: the best, B: flaw but still serviceable... and so on M is monitor quality. A,B and M are most common and usually interchangeable.

68: size in CENTIMETERS

KVL: family.  typically how the guns are set up (horizontally or vertically), location of manufacture. how the socket pinout is arranged, single or dual focus. etc.

74: family designation. if the tube is different from its others in the same family it's here it will be designated different (neck diameter different deflection angle etc)

X: phosphor type. this is the designation for color. other letters designate what color in a monochrome screen (green amber etc)

03: neck components... integral spark gap, deflection yoke if included by tube manufacturer. manufacturer specific use too as well.

you can typically ignore most of the stuff at the end, but you need to have it electrically compatible.