Egret II monitor problems. Help!

[Necronopticous]

Hey guys,

So I recently got motivated to try to figure out & fix whatever has gone wrong with the monitor in my Egret II. I am completely clueless when it comes to this stuff, so I will try to describe my observations and hopefully someone will be able to help me figure out what I need to do.

The first signs that something was going wrong came a while back, when I began noticing that when I powered on the cab after a day/few hours hiatus, the picture would be a bit off alignment (specifically pushed to the left when in vertical orientation). Within a minute or two, the picture would slowly right itself until it was displaying just fine. As time went on, the amount that the alignment was off gradually got worse and worse until the point where basically half of the picture was wrapped back on itself because it was pushed so far over on initial power-up, but it would still right itself after a couple minutes.

Eventually it got to the point where the picture looked like it couldn't even get hold of the sync, and it would flash and roll like crazy for a few minutes, and then, again, right itself all on its own. At this point I got so bummed out that I pretty much stopped playing it for awhile, and when I eventually tried powering it on again after a few weeks there was absolutely no picture at all (the cab still powers up, and I can still hear sound). Once I saw that, I had pretty much given up hope, however, upon trying to show a friend this behavior it actually came up with a picture again, albeit with the crazy flashing/rolling issue for a few minutes, but actually worked again for awhile.

Today was the first time I have tried powering it on in a few months. I was going to record a video to show you guys to help diagnose the issue, but alas, it is back to no picture at all so a video would probably be useless.

I'm super bummed out on the whole thing, and I really, really want to fix my cab and play my PCBs again, but I just don't even know where to start. If there is any additional info I can give that would help diagnose what might be wrong, or anything I should take pictures of or anything, please let me know.

Help meeeeee

[ChuChu Flamingo]

Warming up and stuff fixing itself are usually cold solder joints or bad capacitors.

I recommend changing the capacitors on your chassis. All your symptoms point to it.

[geekmiki]

+1 a cap kit should solve your problem.

First, identify you chassis (probably an MS9-29), then order your cap kit from Bob Roberts: http://therealbobroberts.net/caps.html

It's not really complicated, but it requires basic soldering skills and a lot of patience the first time to replace all the caps, pay attention to polarity, desolder/solder, etc.

I know of people offering this kind of service, but in the UK... http://www.giz10p.co.uk/

As said, if you have basic soldering skills you should be ok. The caps on an MS9 are quite big and not to difficult to change.

Good luck!


EDIT: Found someone doing chassis repairs n the US... http://www.arcadecup.com/

[Necronopticous]

Thanks for the link. I think I will try to ID my chasis and order a cap kit tonight.

[Necronopticous]

From what I can tell, this is indeed the MS9-29, but can anyone help me verify? I snapped this picture:

[geekmiki]

Yep, looks like an MS9-29...

Same as this one...
http://www.jomac.net.au/Nanao%20MS9-29A-T-SU.JPG

In case it helps, here's a cap list (if for any reason you don't want to order from Bob Roberts):
http://www.juniorsrevenge.com/nanaoms929caplist.txt

[Necronopticous]

Bob Roberts has two listings:

MS9-29A color
MS9-29T color

What is the difference between these two, and how can I tell which one I have?

[geekmiki]

I would order the caps in the list I sent, start replacing the caps and then complete the ones missing (if any) from a local electronics store... As easy as that

[Necronopticous]

In case it helps, here's a cap list (if for any reason you don't want to order from Bob Roberts):
http://www.juniorsrevenge.com/nanaoms929caplist.txt

Code: Select all

C951 - 180uF 100v

Is this a typo?

Should I...be worried about other typos? Also, is there any way to know which positions require high temp caps?

[kamiboy]

There is nothing special about high temprature (105C) capacitors, they just last longer. They are usually chosen when capacitors need to be placed near components that give off heat.

Personally I buy only high temprature amps for my own use. They cost a bit more, but not by much.

As for typo, not necessarily. Sometimes capacitors with strange ratings are used, and they are often hard to come by.

[Necronopticous]

Well, I've never heard of a 180uF 100V cap, and there is a factory original cap in that position on my chassis that is 100uF. Pretty sure it is a typo in this case, which makes me worry about the rest of the list. I decided to order the kit from Bob after checking out my local electronics store. My buddy and I are going to do the job ourselves. I'll let you guys know how it goes!

[Necronopticous]

We recapped the chassis last night and threw it back into the machine. We're still getting no picture at all. Any other ideas? ;[

[geekmiki]

Your tube might be dead...

Power on your cab and check the neck of the tube. There should be some light/glow there.
If not, that's rather a bad sign... Dead tube!

EDIT: When you power on the cab, you're getting sound, right?

[Necronopticous]

I get sound. I don't think it's a dead tube because, like I said in the original post, when this first happened, the picture went completely out, then later worked again, and then finally went out again. If the tube died, it doesn't seem like it would have had that behavior.

[geekmiki]

Check as as I said if you get some light/glow from the tube neck... You'll be 100% sure if it's a tube issue or not.

It could also be a defective power supply... You should check your power supply to see if it's sending 110V to the chassis from the AMP connector.

Good luck!

[Necronopticous]

It is fixed!

geekmiki, there was no neck glow but we were pretty confident it was a chassis issue and not a tube issue. I took it to an arcade monitor servicing shop and described the problem and the guy knew what it was right away. It was a transistor pressed up against one of the metal walls. He replaced it this week ($85) and said it fixed the problem, and I verified that last night once we threw it back into my cab. Looks even better than before thanks to the new cap kit we threw in prior!

Of course the neck glow is back now, so just to be clear there are certainly cases where no neck glow can still indicate a chassis issue and not a tube issue.

[moh]

glad to see you got it working! these tubes die hard

[Necronopticous]

[geekmiki]

Great news! Glad you got it working again...

Enjoy!

[emphatic]

Looks great!

[PC Engine Fan X!]

Yeah, it'd good to hear that the Nanao chassis is up and running properly. I recognize that slick Strikers 1999/Strikers 1945 III screenshot.

PC Engine Fan X! ^_~