CurtPalme.com Home Theater Forum

[Dertah]

Hello All,

I have been posting on the AVSForum for some time and I was invited to come over here for more CRT related talk. I see many of the same familiar faces here so I will be brief with my history.

I used to have a Marquee 8110 but sold it with my house 5 years ago. I bought a Vidikron Vision One from Curt about three years ago and it has been sitting in my basement since then. I took it out of the crate last week (plan to hamg it in a few weeks) and saw that glycol had leaked out and that the bellows are sweating.

I am taking the entire thing apart and cleaning it with isopropyl alcohol. So far so good as it does not look like the Glycol went down into the motherboard or the power supplies.

I do have a few quetions though.

1. There is no braided ground wire from the blue neck board cover. The red and Green have them - is this an issue?

2. I am following Tim's directions on tube removal where he says "The metal tip of the anode wire can carry several thousand volts stored inside the tube, even days after the tube was last operated, so be aware that a jolt is possible though not likely lethal." Is there a safe way to discharge this?

3. Tim also says: "The white jumper wire into the end of the tube carries 500+ volts of G2 bias current, make sure to reconnect to the tube pin closest to the base of the jumper or the tube can be damaged." On the Red and Blue tubes the wire is connected as Tim says. However, on my Green tube, this wire is connected to one of the posts in the half moon circle outside of the white plastic area. The pin it is connected to has a number 6 next to it. What up?

Thanks so much for hearing me out.

[CasetheCorvetteman]

If the set has been sitting for 3 years, itll have no charge stored in the tubes after that long.

When you remove the HVs from the block, touch them to the chasis, and have the chasis grounded ( as in have the power cable plugged into an earthed socket outlet, but NOT turned on )

Touching the HV leads to the chassis will dissipate any charge to earth, making it all the same voltage potential and then it cant bite.

[Nashou66]

[stefuel]

I have not tried this but I think it was Scott that said once that he has cleaned circuit boards right in the dishwasher.
God knows I've got plenty of circuit boards to try it on. I'll try it this weekend.

[CasetheCorvetteman]

i cant see an issue with that provided they dont get too hot and they are dried well afterwards, provided the water wont get into any of the components.

[Sparky015]

Not sure I would try putting boards in a dishwasher. You'll never be able to totally dry them out, corroding the contacts even further than they probably are from the glycol, and most importantly, not sure the boards will take the heat generated by a dishwasher. Electronics are not "dishwasher safe".

The only way I would submerse circuit boards is in a sonic cleaner, which is filled with ispopropl alchohol and vibs the boards clean. If you don't have access to one of these, which are generally found in circuit board assembly houses, then I would do as Nash suggests and liberally apply isopropl alch and scrub with a brush. It's readily available and what's used in board production. Can't go wrong with it.

[zGman]

"""However, on my Green tube, this wire is connected to one of the posts in the half moon circle outside of the white
plastic area. The pin it is connected to has a number 6 next to it. What up? """


You have a Barco type tube for green - there is nothing wrong with this and you should
have good results.... Simply put - the G2 is on pin 6, so be sure to lablel and re-assemble
correctly.

G

[Spanky Ham]

I think Scott said they use to put the boards in a dishwasher at Ampro. I don't remember seeing a dishwasher at VDC, so I am not sure if they do it there or not.

What I use to do when I bought a pj was spray the boards with my cleaner that I use for just about everything. 1% Joy, 10% alcohol and the rest distilled water. I would then rinse them with distilled water. I would finish with an air compressor to blow the water off.

[Dertah]

""1. There is no braided ground wire from the blue neck board cover. The red and Green have them - is this an issue?



On Some marquees the braid might be connected to the metal case in between the blue and green tube, that is the HDM or horizontal deflection module.""

There is no ground to the HDM either. SHould I put a new ground wire in where the other two are?

[Tim in Phoenix]

[Dertah]

So I feel very lucky. I have the entire thing apart and although all three of the tubes leaked Glycol it does not seem to have gone anywhere too important - not on the motherboard, not on the back plane not in the LVPS. It does seem to have gotten into the PCB at the end of the HVPS but I have cleaned that out thoroughly.

I can't tell if there is any Glycol in any of the tubes - there are no lines or bubbles. I took the c-element off of the blue tube. I also removed the Glycol fill screws. Only air comes out when I push the c-element in and out. I think they are empty - just purchased 5 bottles of Glycol from MCM...

Thinking of buying new bellows but concerned about getting them on right without ruining the c-element.

[dvh99]

you have to buy new bellows since the old ones were leaking and you do not want to risk them leaking while the pj operates.
throw the old bellows into the trashcan, i did that .
installing the new bellows is a breeze.

bellow removal and install instructions.

http://www.curtpalme.com/Marquee_LC_removal.shtm

[Dertah]

OK - So I just purchased three bellows and will do the install myself. One of them (green) continues to leak slowly as it sits on the table I have it on. The little black allen screws that hold the bellows on are all very rusty. I am going to look for replacements. Anyone have a source?

Also is there a thread about cleaning the lenses and C elements?

[Dertah]

I found a thread on lens cleaning here:

https://www.curtpalme.com/forum_archived/viewtopic.php@t=21589.html

[draganm]

[Dertah]

With many thanks to several of you I have replaced all of the bellows and cleaned every board and surface. Turns out the Glycol leak really was not that bad. The only place it seams to have gotten into is the HVPS. I cleaned that out thoroughly with isopropyl alcohol.

I plugged it in and turned it on and everything seemed OK. Then I heard this intermittent popping sound. It will happen once every few seconds for about 5 or 6 times and then stop for a minute. It is not loud but definitely audible. I did more investigation. Whenever I hear the pop sound a tiny bright spot flashes on the face of all three tubes. The best I can tell, the sound is coming from either the green tube or the high voltage power junction that is mounted on top of the green tube.

Any ideas? Is this a HVPS problem?

[ecrabb]

That snapping is HV arcing, and it can be catastrophic to boards in the set. Don't turn that machine on again until you get advice from Curt or one of the marquee guys like draganm or Athanasios.

SC

[Nashou66]

Hmm, with the set off and lens off take a look at the face of the tube. Just in case you managed a spot burn. Since the glycol got into the HVPS it might be damaged and new one will be needed. I would not use the set till you do get e new one for testing or send your out for Curt to test to Tim Martin in a test machine that it wont matter if the tubes get damaged.

Thinking a bit more it could be contamination in the tube necks. remove the top cover so you have access to all the tubes remove the covers on the plastic tube housing so you can see the end of the tubes, turn it on and see if the flashing is in the tub neck. if so then looks like there might be contamination build up on the cathodes and or grids.

if so you can try to tap it and burn it off.

Hopefully Curt or Tim have seen that before, the contamination will light up the tube face but i have not seen it in a concentrated tiny dot like you described, that sounds more like spot burn.

Athanasios

[draganm]

yes stop running it or you will damage the HDM.
whenever I replace bellows for people I always look at the HV wire. It's normal for this wire to be "disturbed" as you work on the LC chamber. I will always wipe the wire down with Isopropyl Alch. and also look at the boot on the tube bell. Clean this area as well with IPA and a q-tip. then fill the loose fitting boot with RTV. let cure for 24 hours
A lot of times, especially on early VDC or Christy machiens they routed the HV cable through the same slots as the deflection and focus coil leads. These should be moved so they exit on the side-slot of the plastic housing. since the 9" tube HV boot is so close to the slot, Put a small loop in the cable to help it exit the slot without binding on the boot.

[Dertah]

I really don't know what I am talking about but I don't think it is a spot burn - the tiny dots appear in random places and only appear for a brief instant (along with the pop sound). Does contamination in the tube necks seem likely given that it is happening on all three tubes at once? The tiny dot jumps around the face of the tubes but always appears on all three at the same time. Athanasios, what do mean by "tap it and burn it off"? I can't be sure but I really think the popping sound is coming from the HVPS junction box on the green tube and not the green tube itself.

I will look at the HV wires as Dragan suggests.

Also, I do have a spare HVPS that I think works (I have an 8500 that I picked up for parts). Anyone see any danger in swapping out the HVPS and turning it on again to see what happens?