Author Topic: area 51 monitor help!! (Read 20729 times)

MKFan4Life · « **Reply #40 on:** October 27, 2010, 12:20:08 am »

Been looking over it. That solder joint you reflowed on the flyback that we all saw earlier in this thread looks BAAAAAAD!

The pin sticking through is not joined with the solder AT ALL. I hope the trace (which is now lifting pretty bad) will take some fresh solder. I think it will be ok.

Your 2-pin connection for your degauss has the solder joints cracked all the way around both pins and is wobbling all around. I'll reflow them with fresh solder. Found one place where 2 pins are touching on the back of the chassis, but I think they are linked to the same trace.

Your new flyback like the one pictured here:

does not line up properly with the screw at the top where it attaches to the metal bracket for added support, but there is a hole in the bracket that I think I can make work to support it.
It would have worked better if you bought this model:

but I think they are functionally the same. Also, the little clip that holds the red and gray wires was broken when I opened the package. (No biggie, just serves to guide the wires somewhat.) Might have been that way when you received them as I could not find the broken off bit in the package anywhere.

Funny thing, too (not surprising being a Neotec) your chassis looks ALMOST identical to my Medium Res NT-2701. VERY SLIGHT differences.

Will likely start the work on this tomorrow afternoon man.

MKFan4Life · « **Reply #41 on:** October 27, 2010, 12:49:51 am »

Quote from: Kevin Mullins on October 26, 2010, 10:02:23 am

Keep an eye out for ANY solder joint that may look like it has a ring around it.
This one looks like it may be for the vertical yoke winding.
(for the collapse issue)

The white horizontal lines may still be the flyback (screen voltage pot) going south.
(but could be a number of things also, like caps, connections, etc)

My gosh! You've got darned good eyes! Just checked that exact pin, and sure enough, it's in the same state as his degauss pins... cracked almost completely around the joint! I think I'll be on this chassis a while adidas1984X! And yep, it's for the vertical yoke winding. Definitely going to reflow EVERY joint where pins for connectors are.

adidas1984x · « **Reply #42 on:** October 27, 2010, 06:08:20 am »

yea I emailed the guy about the flyback he said thats the correct one for my chassis lol

MKFan4Life · « **Reply #43 on:** October 27, 2010, 07:30:57 pm »

I believe there are a few models that will work with these Neotec boards, 'cause when I Googled them, yours usually came up in a listing with the other models, but I think there are simply differences in the housing.

I'm going to fix all the bad solder joints first, especially the one on the flyback and that one Kevin spotted (am betting that is your main culprit!). Then I will test it out on one of my spare 25" tubes and see if it displays ok and if your initial symptoms have improved. That will tell us if it was the flyback I hope, unless it ended up getting damaged from the arcing. I'll keep you updated man.

Pics of your ACTUAL old flyback and the ACTUAL new one so you can see the housing difference and the broken wire clip on the new one:

The arrow points to a spot I could likely use for the hold-down screw for your new flyback:

The arrow points to the spot the screw will have to enter on your new flyback:

Here's the broken clip on your new flyback:

And another view of the broken clip:

MKFan4Life · « **Reply #44 on:** October 27, 2010, 11:50:42 pm »

Can someone tell me, since this trace is all but burned OFF at the flyback pin, would it be best to:

1. Slightly bend the pin towards the remaining trace and try to get it to take solder...
OR...
2. Use a jumper wire (what gauge?) to connect the pin on the flyback to the horizontal yoke pin the trace leads to...

Also, I was planning on making all obvious repairs to the joints I found that needed attention (just look at all the cracked joints!) and then testing the chassis on a tube BEFORE attempting to install his new caps and flyback (just to see if one of the repairs fixed the original problems he had). Would this be a bad idea if that old flyback was internally damaged and caused the initial arcing on that joint? (Since I might end up with more damage.)

Should I just go ahead and use one of the above options along with installing the new flyback instead of retesting the chassis with the old flyback?

THANKS!!!

lilshawn · « **Reply #45 on:** October 28, 2010, 12:43:03 am »

Quote

Can someone tell me, since this trace is all but burned OFF at the flyback pin, would it be best to:

1. Slightly bend the pin towards the remaining trace and try to get it to take solder...
OR...
2. Use a jumper wire (what gauge?) to connect the pin on the flyback to the horizontal yoke pin the trace leads to...

1... if the pin will reach well within a newly scraped area on the remaining trace. (3mm or 1/8 inch) if not, bend the pin in the direction and use some flux braid or some stripped off electrical wire (110v) to make a connection to the trace. be generous with the solder.

MKFan4Life · « **Reply #46 on:** October 28, 2010, 12:47:13 am »

Thanks! Going to see if I can connect it to the trace again first. There are really LOTS of cracked joints on the chassis. I am hitting all the large ones and any that I can tell are cracked or iffy.

UPDATE:
I tried. Looks ok, but the trace was pretty bad.

Scraped and cleaned before:

Shot 1 after:

Shot 2 after

Shot 3 after:

Wanted to check the HOT, but I've not done that before. Isn't this the HOT (C4769)?

And this from another angle:

I read a bit about checking for shorts from base to emitter and collector, but I have a digital multimeter and am not sure how to check it properly. In the circuit, it seems to be showing .000 volts on the diode checking selection when black lead is on base and red on emitter... with it on collector, starts at 1/2 volt or so and continues until it reaches about 2 volts and then just reads ".OL". Reversing the leads reads .000 for base to emitter AND base to collector. (Base & Emitter labeled on chassis.) Is this unreliable until taken out of circuit for testing?

lilshawn · « **Reply #47 on:** October 28, 2010, 11:38:23 am »

to properly check it you will have to remove it.

even if it tests okay (even with a B&K checker i have) they test okay, but fail when under load.

do a resistance check between the outside legs and the middle. if you read a short, it's definitely bad. if not, it's probably still good.

if you suspect it's bad or iffy, it's worth the $5 to just replace it , be done with it, and have one less thing to worry about.

MKFan4Life · « **Reply #48 on:** October 28, 2010, 05:26:58 pm »

So there's no doubt this IS the HOT right? There are a couple more transistors with rather large heatsinks on the pcb, but this is the biggest and being near the flyback and horizontal width coil, I figured it'd be the HOT for sure.

Kevin Mullins · « **Reply #49 on:** October 28, 2010, 06:00:49 pm »

C4769 - Yes, that is the H.O.T

Your trace repair looks fine, but just a note for future reference maybe.......might come in handy.

I keep all the leg clippings from cap kits, resistors, etc, for trace repairs like this.
So like I would have used a leg clipping from one of the larger caps or something (thicker legs) and made a small loop on the end to fit over the flyback pin and then bent it to follow the original trace, and then soldered it down good.

Just an idea for ya.

MKFan4Life · « **Reply #50 on:** October 28, 2010, 06:06:55 pm »

Thanks for the tip. I have actually done just that sort of thing in the past when installing a cap kit and ran into a damaged trace. But yeah, I figured the thicker legs would be best for something like a flyback. Thank you.

RejectedManiac · « **Reply #51 on:** October 28, 2010, 11:14:08 pm »

I know chad from arcade cup uses 16 gauge wire for traces that are burned away. He just strips the wire solders the wire to the leg with the trace gone and fallows the trace where it leads and solders there to make sure there is no break anywhere along the trace. Extra security I guess. As for the flyback I would go ahead and replace it. It will save problems down the road. Also it's out of the cab and he can't do it so might as well get that out of the way esp since it's already bought. It will add extra life to it of course. By the way just heard his problem on arcaderepairtips.com podcast. They said def replace the caps and flyback. They also mentioned the coil as well to take a look at.

MKFan4Life · « **Reply #52 on:** November 02, 2010, 07:34:48 pm »

Been slowly continuing work on his chassis (was on vacation for a few days over the weekend, so wasn't able to get much done during that time). After the initial reflowing of as many solder joints as I could find, the chassis was running pretty good in my opinion. Even with it running up to 2 hours (I think I told adidas1984x I ran it for an hour, but it was really about 2), I never saw the collapse issue take place. There was certain times I fired it up and saw the flyback or retrace lines slightly visible, but they usually never got any more evident as it operated longer and adjustment of the Screen control fixed the issue.

I am replacing all the caps now and going to do the flyback (sorry, I am a slow worker with stuff like this). I am also reflowing joints on the neckboard, because I tried myself to slightly jar the frame of the monitor while testing the chassis after the reflowing of the bad/cracked joints on the main chassis and noticed red-colored horizontal tearing if I hit it rather hard, but nothing with just a slight tap or so. Then I isolated it to the neckboard. The chassis itself seemed stable when jarred, but tapping on the edges of the neckboard lightly produced the same results as jarring the frame harder.

You really wouldn't be jarring the cabinet around hard enough to do this normally, unless you got pissed at the game, lol. I'm not sure if the jarring was disrupting connections with the pins on the neck of the tube, or if it is a bad joint, so I'm reflowing anything there that seems in question.

adidas1984x · « **Reply #53 on:** November 02, 2010, 07:42:58 pm »

take your time Im in no hurry you are awesome thanks for all the help

MKFan4Life · « **Reply #54 on:** November 06, 2010, 08:38:15 pm »

Got his chassis all recapped and retested it after the kit to insure all is well before I start here in a minute on his new flyback. I think honestly it is repaired right now, but he has the new flyback, and I am going to go ahead and install it in case that collapse issue is lying dormant at the moment and the flyback is the culprit.

I repaired the white Focus wire from the flyback to the tube socket (was weak enough inside socket it broke loose during cap kit install), and also stripped, tinned, and resoldered his red G2 wire to the neckboard as it was very frayed. Here's a before and after of the chassis:

lilshawn · « **Reply #55 on:** November 06, 2010, 11:36:35 pm »

i would remove the vertical deflection IC and make sure it has enough thermal grease on it. i believe it's IC301

often they are applied VERY sparingly, and they can overheat. and it takes 2 minutes to do.

MKFan4Life · « **Reply #56 on:** November 08, 2010, 12:09:46 am »

Ok, I see that IC. It appears to have enough that it's seeping from around the sides a little bit. Also, there are about 13 pins to desolder, and I don't have any thermal grease to replace on it, so I think I won't chance making it worse by removing it.

I know it might be the smart thing to do, but if I check everything on the chassis, I'll never get it back to him. It is working fine from what I've seen after the cap kit, but I am right now installing the new flyback anyways since he has bought it. (got behind a day or two ago and just now got the old one out)

lilshawn · « **Reply #57 on:** November 08, 2010, 12:58:15 am »

if it's seeping out around the edges, it's probably has enough then.

check the resistors in front of the IC301, they dump the voltage down to drive the IC's VCC, sometimes they get hot and lose value. other than that, it looks great.

MKFan4Life · « **Reply #58 on:** November 08, 2010, 01:30:46 am »

I'll check those.

Just had to slow down to do some research on the flyback wire color coding. I believe his new flyback has the G2 as a purplish/gray wire and the Focus as a red wire, where the old one had red for G2 and white for Focus. Glad I slowed down. The new flyback's red wire is rated at 20KVDC (like the white on old flyback) and it's purplish/gray wire is rated at only 1000VAC/1200VDC (like the red on old flyback), so I could have reversed these if I hadn't read a few threads on here first. Also noticed where they emerge from at the bottom of both flybacks, which seems to confirm the coloring is not a true sign of what they're for. (unless this can vary)

So the Focus will be the thicker insulated, higher voltage-rated wire I guess. Always learning something new... cool.

lilshawn · « **Reply #59 on:** November 08, 2010, 01:37:26 am »

don't you love it when they change things.

i wired up a trailer brake controller for my boss, it had white, black red and blue wires.

so you'd think red was positive, black was negative, white to the brake switch and blue to the trailer? (or even maybe blue to the brakes and white to the trailer)

nope

it was positive to black, negative to white brake switch was red, and the trailer was blue.

so much for standards... i guess it kind of makes sense.. but...

MKFan4Life · « **Reply #60 on:** November 08, 2010, 01:42:44 am »

People who change standards like these should be shot... ok... at least tickled really hard until they can't breathe! Lol!

MKFan4Life · « **Reply #61 on:** November 08, 2010, 10:52:50 pm »

Couple more hiccups on this flyback installation.

The footprint has a part that slightly juts into the way of a ceramic disc cap, unlike the old flyback. I was able to bend the cap out of the way enough to clear it. But then, when I tried to seat the flyback, the 2 pins that appear to be there for mounting support (right under the Screen and Focus knobs), won't allow me to seat all the way down. They are a little farther away from the main 10 pins than those 2 pins on the original flyback. Here's a pic:

Also, I don't know HOW I didn't see these cracks as soon as I removed the old flyback. But they are very evident sitting on the work table:

I REALLY think the MRCFT-252 should be put back in this chassis. But I have seen the MRCFT-216 listed for "NT-2515C" (this chassis has an "M" added, thus "NT-2515CM") on arcadecup.com and another site. Not sure where adidas1984x bought this MRCFT-216 from, but he said they told him this is what fits his chassis.

Does anyone know if I can just bend these 2 support pins enough to make the flyback seat down all the way (while still allowing them to poke through and be soldered), or will this cause problems?

grantspain · « **Reply #62 on:** November 09, 2010, 04:22:08 am »

i would just bend them to fit if it were me doing this job

adidas1984x · « **Reply #63 on:** November 09, 2010, 06:15:11 am »

Yes the flyback I bought from chad at arcade cup I would prefer to have the original for good piece of mind.............
or would it be ok to use this one without damaging anything ...... i just need advise LOL

MKFan4Life · « **Reply #64 on:** November 09, 2010, 06:59:11 pm »

Contacted Neotec Support from the email link on their site and a "Peter Wang" replied with this:

Quote

you can use ft- 216 flyback. nt-2515cm is very old one. so the layout is little different with the newer version.but the flyback are same.

neotec
peter

So I will go ahead and bend the pins enough to allow them to still be soldered, but let the flyback seat all the way down.

I actually am wondering what it would hurt to cut those 2 pins off completely? Are they ACTUALLY connected to anything inside the transformer? Or do they dead-end somewhere inside and are simply for support only? The traces on the chassis for them lead to ground and there are 2 other pins that solder to traces leading to ground. Anyone know for sure?

MKFan4Life · « **Reply #65 on:** November 10, 2010, 01:15:23 am »

Got the flyback installed and repaired that nasty trace a lot better. Used 14 gauge home electrical "Romex", as some like to call it, wire. Thanks for the suggestion lilshawn, and also RejectedManiac who mentioned Chad at The Arcade Cup using a similar method.

Here are some pics:

New flyback installed...

...and the trace repaired better:

Also found a bad joint on the remote board...

...and reflowed it:

Tomorrow I hope I can do some final testing and start packing it up for adidas1984x.

lilshawn · « **Reply #66 on:** November 10, 2010, 02:54:05 pm »

that romex can carry a ton of current, no chance of that burning out.

MKFan4Life · « **Reply #67 on:** November 10, 2010, 06:12:09 pm »

Yeah. For future reference, I will never wire an entire house with the 12 gauge. That darned stuff is so stiff it's tough to manage when routing it. My wife's uncle talked me into doing it with our house 'cause he said it's nice to have that along with 20 AMP breakers while you're building so you can hook up your compressors, saws, and the like right into your outlets instead of dragging extension cords around everywhere. Twice as frustrating is fishing it through deep holes in exterior log walls. ARGH!

MKFan4Life · « **Reply #68 on:** November 14, 2010, 09:53:55 pm »

The final testing went well. The flyback seems to be working great along with the newly-installed cap kit. I left it running for several hours with zero issues and even banged around on the frame of the monitor a little to see if there might still be any bad solder joints. It's rock solid. Played through Mortal Kombat 1 with absolutely no glitching, collapse, or anything to note. Shipped it back out to him Saturday morning.

Kevin Mullins · « **Reply #69 on:** November 15, 2010, 08:06:35 am »

Good deal.

adidas1984x · « **Reply #70 on:** November 17, 2010, 08:29:09 pm »

I got the chassis back and it looks fantastic MKFAN4Life did a amazing job I cant thank him enough
I just finished installing it and doing the necessary adjustments and it looks amazing thank you again and pics and vid to follow

MKFan4Life · « **Reply #71 on:** November 17, 2010, 08:36:32 pm »

Awesome! Glad it made the trip safely and you got it all back together ok! Definitely look forward to your updated restoration vids on that cab man.

adidas1984x · « **Reply #72 on:** November 17, 2010, 10:04:00 pm »

vid of the awesome working monitor

grantspain · « **Reply #73 on:** November 18, 2010, 05:40:22 pm »

MKFan4Life deserves a big pat on the back for sorting that out-bloody rare to find anyone these days who is willing to help
he's got my respect

lilshawn · « **Reply #74 on:** November 19, 2010, 01:24:16 pm »

*thumbs up*

smartbomb2084 · « **Reply #75 on:** November 19, 2010, 07:59:21 pm »

Good job man. That's why we call this arcade thing a COMMUNITY.

As the old saying goes... One hand washes the other and both hands wash the face. Then... we eat!

MKFan4Life · « **Reply #76 on:** November 19, 2010, 08:07:52 pm »

So true. Just don't try washing your hands or face, or eating while working on your arcade machines... lol!

lilshawn · « **Reply #77 on:** November 20, 2010, 04:03:01 pm »

Quote from: MKFan4Life on November 19, 2010, 08:07:52 pm

So true. Just don't try washing your hands or face, or eating while working on your arcade machines... lol!

unrelated to OP but: i had a cab come in last week... had 2 crackers smashed up UNDER the lexan on the control panel. i'm like WTF?!?!?


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