Anode sparks!! Updated with video

[bluevolume]

OK, so I'm working on my arcade tonight, and something bad happens.  I fire up the monitor, and it starts making this loud squeeling sound, then I hear this crackling sound.  So I turn it off immediately, let it sit for a bit, turn it on again.  It does the same thing, and looking closer before I shut it off, I see a bunch of blue sparks going on underneath the anode cap.  Probably shining through the inside of the tube actually.

I give it some time to rest, turn it back on and it sounds fine, but there is no picture.  What the crap happened?  Its a WG 25" k7000.

[bluevolume]

I guess none of the monitor guys are on this late.  I'm hoping this monitor isn't totally fried, I really don't want to have to replace it.

[Ken Layton]

Sounds like a moisture/humidity problem if it's under/around the rubber suction cup. Possibly it's not firmly clipped into the anode hole in the tube.

[bluevolume]

Ken -- I've been reading other threads and I was hoping you would respond.

I'm not comfortable discharging the monitor; could I just try and push the anode on with a wood stick?  I know that sounds ridiculous, but until I can get a service guy out here to look at it its about all Ive got.

[Ken Layton]

You could do it if the power were off. Wear leather or rubber gloves too.

[bluevolume]

I just talked to a local technician and he thinks the tube is bad.  Does that sound right?  I'm thinking about putting in a cap kit myself now, but i don't want to waste my time on a dead tube.

[Ken Layton]

If the sparks are inside the tube then the tube has a crack in it and air is now inside. The tube is then considered destroyed.

A friend had a game he bought from someone sight unseen. The guy said it worked. But when we got it, the whole game showed signs of corrosion all over the metal parts in the cabinet. We plugged it in and I'm greeted with a bunch of sparking inside the tube under the suction cup. I shut it off and took a look with a good strong work light so I could see. Sure enough there was a crack in the glass tube and air was in the tube. I asked the guy where the game had been stored---an unheated shed in his back yard for 3 years. The temperature extremes (cold mostly) had gotten to the tube. We ended up buying a brand new picture tube for this monitor (it was a medium res) and a new flyback too since it showed signs of failing.

[bluevolume]

I really appreciate you helping me diagnose this.

Here's some more info to add to the scenario.  The monitor did this same type of thing last week, but I didn't leave it on long enough to see the sparks.  Later that same day, the monitor fired up and started working, and had more or less worked fine up until last night.

I will discharge the monitor tonight and take a good look for a crack in the tube.  I'm hoping that isn't the problem, and based on that it worked up until now the odds are in my favor.

The squealing noise though, is that indicitive of a bad flyback?  It wasn't a high-pitched (normal) squeal, it was much more audible and lower frequency.  Also, whenever the monitor was on, while it was working, there was a hum coming from the chasis that seemed excessive.  Dry caps?

Once again, I really appreciate your help.

Edit: The exact model is WG 25k7197

[Ken Layton]

Well then I'd install a capkit and a new flyback then see what happens.

[bluevolume]

Well then I'd install a capkit and a new flyback then see what happens.

Off to Bob Roberts I go.....

[bluevolume]

I have removed the chasis, getting ready to replace the flyback and put in a cap kit.  Here's something that was wierd though, when I tried to discharge the tube, there was no spark or anything.  I was hoping to hear that snap so I knew I was discharging it properly, so I actually fired up the monitor again to make sure it was charged and tried it again.  Still nothing.

Is this a good sign?  Sounds like the board isn't powering up, so that's where the problem is.  The tube looks OK from what I can see, no cracks or anything.

[grantspain]

i very rarely bother to discharge tubes as most modern monitors do not hold charge,its nothing to worry about

[bluevolume]

i very rarely bother to discharge tubes as most modern monitors do not hold charge,its nothing to worry about

Hey, thanks for the reply.  Did you read through the rest of this thread?  Any comments?  Before I took the chasis out, the monitor had no picture and didn't seem to have "power" in the tube.  When it was working, if I turned it on then off you would see the picture sort of collapse into a small dot in the center.  But after the episode last night, it doesn't do that anymore when powered on/off.

[Ken Layton]

Your monitor may be going into shutdown mode. Possibly because of bad capacitors.

As I said before put in new capacitors, flyback, and check the solder joints all over the chassis for bad joints (particularly at resistors R89 and R101).

There's an outside chance the voltage regulator IC bolted to the chassis next to that large white ceramic resistor could be bad.

Remember when changing the flyback the two "flying leads" coming out the bottom go to the neckboard and the wire colors may be different on the replacement. The larger of the two wires is the "focus" wire which connects inside the picture tube socket on the neckboard. Don't splice this wire as it carries 8,000 volts when in operation. The smaller wire is the "screen" wire which goes to the single pin terminal on the neckboard. I usually splice this wire to the old one from the flyback being removed since the replacement does _not_ come with this terminal.

[bluevolume]

Now that I have the chasis out, I think I'm going to order the parts and take it to an experienced repair guy.  I know it will be done right, and he will be able to test it for me before I put it back in.  Amusements Plus is only 20 minutes from me, might as well take advantage of a great local resource.

[Ken Layton]

Amusements Plus is a great company. My friend Steve Mildenberger (Steve's Amusements) here in Olympia orders from them. They've got great prices and fast service. Too bad they don't have a website though and they don't have a catalog. tell them Ken Layton and Steve Mildenberger from Olympia, Washington say hi.

[bluevolume]

Amusements Plus is a great company. My friend Steve Mildenberger (Steve's Amusements) here in Olympia orders from them. They've got great prices and fast service. Too bad they don't have a website though and they don't have a catalog. tell them Ken Layton and Steve Mildenberger from Olympia, Washington say hi.

I found them when I was restoring my first pinball, and I was really impressed.  Their prices are better than a lot of the mail/internet places and they are right here!  Dave is their CRT guy and I'll be taking my chasis over to him tomorrow.  Hopefully he can give me some good news.

[bluevolume]

OK, so I get word back that the monitor chasis is functional, but could use a cap kit and maybe a new flyback.  The technician said that he bench tested it and it should work with my tube.  He suggested cleaning the area where the anode connects with rubbing alcohol, making sure to get any dust out of there.

So I did that, put it back together, and what do you know, it works!  It actually looks pretty good, but I think I will still put the cap kit in it.  Its a 1991 chasis, so it probably needs it anyway.

[johnnya]

I've been in there several times. The guys at the parts counter are helpful, although they're not exuberant. I've only said hi to the monitor guy. I haven't brought anything in to be fixed by him, since I've been able to fix it all myself. Nice to see some Rochester peeps around.

[bluevolume]

I've been in there several times. The guys at the parts counter are helpful, although they're not exuberant. I've only said hi to the monitor guy. I haven't brought anything in to be fixed by him, since I've been able to fix it all myself. Nice to see some Rochester peeps around.

That place is great for getting parts locally, but it always seems a little bit "soup nazi"-ish. 

Cool to know there's another ROC guy on here.  Do you know if Chad or Dave (the Game Room show guys) are on this board?

[Rickn]

Dave Wilson and all the guys at Amusements plus are good people. Dave will go way out of his way to help.

These guys have supported me and my products for years... so of course I am biased. But that is how I try to pick my distributors.


Good luck

Rick Nieman
Rick@Niemandisplays.com
www.niemandisplays.com

[bluevolume]

Dave was able to test the chasis for me and save me from buying a new monitor (monitor is back together and working now).

I'm actually going to stop down there tomorrow and pick up a couple joysticks and buttons!

[johnnya]

Are the guys there the people that put the Game Room show on? I e-mailed the guy with some pics from last year's event, and he seemed nice.

[bluevolume]

Are the guys there the people that put the Game Room show on? I e-mailed the guy with some pics from last year's event, and he seemed nice.

Nope, different guys.

[johnnya]

Oh, ok.

Are the guys there the people that put the Game Room show on? I e-mailed the guy with some pics from last year's event, and he seemed nice.

Nope, different guys.

[bluevolume]

Received my cap kit and flyback from Bob Roberts this week (biiig thumbs up to Bob) and decided to see if I was up to the task.  About an hour and a half later, I had swapped out all of the components and was ready to give it a test.  My confidence was low, since this was by far the most in-depth electrical job I'd ever done, and the fact that this chasis appears to have had a few major surgeries in the past.  There were broken traces that were replaced with wires, components soldered on to the bottom of the board, and a few connection points that were burned to a crisp.

I put it back in and connected it up, and to my almost disbelief it worked!  A few adjustments to the screen and focus, and bringing the brightness back down, and I was staring at a beautiful screen.  I was very happy to have this monitor back in service, and proud of myself for actually getting it done.

I did have some problems with an arcing sound around the anode again, though it wasn't visible.  I adjusted the anode a couple times to make sure it was seated securely, and the sounds eventually went away.  I was also happy to see that the chasis no longer hums now when the monitor is powered up.  Very cool.

[bluevolume]

OK, well SON OF A BI***!  This 'sparking' problem is back, after all of the work I did on this monitor.  I'd really like to smash it with a sledge hammer, but I'll wait for one more diagnosis.

Is it possible that humidity is causing this?  It seems to follow a pattern of when we have lots of rain (my cab is in the garage while I'm building it).  The symptom is when I turn the monitor on it makes a loud squeal and you can see blue sparking inside the tube around where the anode cap is.  The sparks are definitely inside of the tube.

Attached is a video of it.   This is with the lights off so its a bit hard to see, but the circle with the blue glow around it is the anode cap.  Includes sound so you can hear the horrible squeal for yourself.

[grantspain]

you can't keep a monitor in a place that suffers condensation.
stick the cab in your nice,dry house for a week and see what happens

[AcidArmitage]

coooooooooooooool 

[bluevolume]

coooooooooooooool 

Not really!  I want to get this freaking project done before it gets cold, and this monitor problem is wasting all of my time.