WG K7000 (7191) P538 25" 120V Popping Noise

[supadave]

Ok, I got a strange issue here. I acquired a second chassis. It was used but I was told it worked. When I fire it up, it does sorta work. Let me explain it as it goes through it's warm up.

1. Turn on the power, Tube lights up, picture comes up like normal.
2. After about 10 seconds there is an intermittent popping/snapping noise coming from what I can tell the neckboard area about every 2-3 seconds. With every pop noise the screen will flicker as if it has no power. (on and off) Throughout a 10 minute span the pops get less and less frequent until there is none. Eventually the monitor stablizes and becomes operational.
3. I can not see any flashes of electric with the lights off or anything.

I have a cap kit on order but I'm conserned that this may not be enough. Any ideas?

Thanks

[SirPeale]

Sounds like a poor connection in the socket.  One thing you can do is  G E N T L Y  bend out the pins ever-so-slightly.  And I'm talking a /minute/ amount here, you do it too much and you'll either break the pin off, rendering the tube useless, or break the neck, rendering the tube useless.

Or it could be the focus wire that goes into the socket.  What kind of monitor is this?  (which you should have specified in your first post, BTW, ahem ahem.  )

[supadave]

didn't realize tube type was an issue. I'm not sure the tube type. I'll have to look and see.

btw.. where would the focus wire be located?

[qrz]

that would be the mid sized wire from the fly.
thickest is the anode lead                30kv
then focus                                        6kv ~ 12kv
thinnest is for the screen grid          150v ~ 500v

the focus pin on the crt will be in the "key" area.  usually , the focus itself is affected if arcing occurs here.
inter electrode arcing would produce a similar symptom. but, that should be visable in the neck...
no purple haze ?

qrz

[supadave]

Not that I noticed but I'll check again when I get back to working on it. I have twin 1 year old girls so I have to be work on it late at night after they crash. What I've heard so far makes alot of sense. The neckboard isn't on the tube pins as tight as I think it should be. I noticed that there was some (silacone type stuff) that kept the board tight that is missing. I did have the neckboard off when I had the chassis out. I'm wondering if it loose connection. I remember pushing on it pretty good to try and get contact and it never made much differance. I'll work with it some more..

Thanks.

that would be the mid sized wire from the fly.
thickest is the anode lead                30kv
then focus                                        6kv ~ 12kv
thinnest is for the screen grid          150v ~ 500v

the focus pin on the crt will be in the "key" area.  usually , the focus itself is affected if arcing occurs here.
inter electrode arcing would produce a similar symptom. but, that should be visable in the neck...
no purple haze ?

qrz

[supadave]

UPdate:  I found a pin on the tube neck was bent over and not inserted into the the neck board correctly. I also found that the Key pin (the one isolated by itself) was missing!!!!  yes missing.. looked broke off. Yes, I am a total noob and just started learning monitor repair a few weeks ago and totally missed this. Did I mention I only paid 100 bucks for the cab with all the fixens.. just the monitor dead.. lol

anyways, I bent the pins back.. and that broke off pin I actually repaired it.. yup, soldered a replacement pin together onto the stub, and used glue and caulk to hold it all in place.. Did it work???  HELL YEAH!!!! after 3 days of setting up, I installed the tube, the chassis and the thing looks gorgeous!! I ment to post some screenies when I was at work today but got busy.. I'll post one tomorrow.

Now I just have one other chassis to get fixed and i'll have 2 good ones and a working tube. The other chassis is dead and i'm still trouble shooting it.. I have another forum thread discussing it..