Fun with MLD's that are a little "off", lol

[sccarlso]

Read an older post on this :  https://newlifegames.com/nlg/index.php?topic=44418

But the issues described for the failing rear MLD screen don't really match what I'm seeing.   Thinking it may be something other than the entire rear screen failing.

Got a G23 MLD machine, and it looked fine initially.  But after loading a few different games.   Specifically Firehouse Hounds exposes the issue the most.

Front LED screen is perfect.  But the color red is off on the rear screen in the MLD and only the images of the 7's on the video reel reel pixelates very slightly.  The background colors are perfect.   i.e.  The most noticable are the Red 7's and the fire alarm bells display on the screen with a green hue and have that slight pixelation.  But it doesn't go out completely anywhere on the screen.

I've had screens display the wrong colors and pixelate slightly like this in the past with std screens, and in those cases, it was either a loose or just a bad VGA cable.  Replaced it and make sure it was secured tight and that was it.  Those old VGA cables can do that, sometimes just wiggling the cable at the brainbox makes the colors correct with a solid image, which told me it was the cable itself.  And it was.

Haven't tested yet, but have a new TrippLite VGA cable (they're more expensive but thick and usually the best for these older machines).   As well as a new "short" VGA cable for the "looping" VGA cable on MLD screens.    Worth trying as it's a cheap fix if that's it.  If not, I'll still be able to use the new VGA cables at some point!

If connecting the new cables has no effect at all.  I know many have had various issues with MLD screens and fixed them up.     
I can post a screenshot if it's visible on a static image, or a short vid if that's the only way to see it.

Wondering if it could also be the video card?  This brainbox originally had a 625 with on board video.  While it technically works for MLD screens, you "should" have the PCIe video card.   So I put a different 660 brainbox in there.   I guess I should check by removing the video card and plugging back into the on board video to see if the issue remains to rule that out.

Would be interested to know if that behavior indicates a failing A/D board.  Or if replacing the rear LCD screen is the only way to fix it.
If it's the A/D board that would cause this, I'm thinking that's easier to replace than taking the whole screen apart to put in a new rear LCD screen.   lol

Also, it's a 4 fan model.  Kortek KTL220MD-04    Fans are ok, but I'd like to replace them.   Anyone know if it's possible to replace the fans without removing the entire display? Or do you need to remove it entirely to be able to replace the fans?   

Thoughts from the experts, or those who have repaired MLD screens would be very helpful!

Thanks!

[sccarlso]

Objection your honor...   Asked and answered. 

Should have tested my hunch first!   Removed the DVI cable at the brainbox, spray a little electronics cleaner on the PCIe card socket and the cable end for good measure.  Plugged it back in making sure it was secure and tight.   

Fixed!  Both the MLD screens are crisp and the rear LCD now displays the proper colors and no pixelation!  Phew.  Really didn't want to dig too deep into that MLD!    If you have a similar problem, clean and ensure the display cable is secured tightly!


Second question still remains though for anyone who has replaced their MLD fans on the 4 fan model KTL220MD-04    Fans are ok, but I'd like to replace them.   

To replace the four fans, is it's possible to replace them without removing the entire display from the cabinet?  Or do you need to remove it entirely and remove the front LCD screen to be able to replace the fans?  It seemed that had to be done on a youtube video I saw.  But that was for the 3 fan model MLD display.

Seems pretty stupid to have to do that much labor just to replace the fans...   But it wouldn't surprise me, as with many components IGT uses the designs are usually to make money from failures/full replacements and not make it easy to keep them running well.

Thanks!

[sccarlso]

And answered again searching posts.

Rick Hunter posted that for both 3 and 4 fan MLD's, you have to pull the whole dang thing just to open the back cover to replace the fans.

Pretty ridiculous but it is what it is.   

The more you know...

[kwcolor1]

Glad to hear you figured out the problem with the colors on the back monitor and it was an easy fix. Let me know if you replace the fans. I have the new fans that I ordered and am ready to start the project of replacing all 4 fans based on the YouTube video I watched (probably the same one as you) but I’m a little hesitant to start the project. Seems like a bigger job than it needs to be.

[sccarlso]

Ya, I ordered 12 of the OEM Delta fans from Digikey.   I have 3 MLD machines, so might as well just do all three of them assembly line style!  lol

On the 4 fan models, there's no internal blowers apparently like the 3 fan models which is nice.   And looking at prior posts with pics of the 4 fan model with the back cover removed, doesn't look too bad.  A few screws to remove the screen, then you have access to the back cover screws to get to the fans.  After I've done it once, the other two will be easier!

When I do it, I'll also blow any dust out of the heatsink as well.   Replacement MLD screens are expensive!  So if your MLD screen is good now.  And you want to keep them that way, replace the fans and blow out any dust so they stay cool.  They're likely the original ones that are 13 yrs or older.

It'll be a pain, but once it's done they should run well for a long time. 

[kwcolor1]

Great information, you having multiple machines to do makes my job doing 1 seem like a piece of cake. I’ll have to go through the old posts and take a look at the pics of the inside with cover removed. Are you going to attempt to clean between the 2 displays. The YouTube video I watched the person doing it recommended that while it’s all apart but I didnt know if that was asking for even more trouble.

[sccarlso]

If my screens were dirty, I might.  But all of them are nice and clear.

So not going to do it.  But if one of them was dirty enough, I'd look at the effort involved and if it wasn't too much effort or risk of damaging something, I'd give it a go and be very careful.

But I'd rather take apart less so it's easier to do all of them and be done.

[kwcolor1]

Yes that makes complete sense. I guess I’ll assess that when i open it all up and make sure it’s clean. Thanks for all the tips and good luck!!

[sccarlso]

Well I "thought" it was fixed!

But no.  While switching to a new cable did correct it immediately.  About an hour later, the rear LCD again changed the red colors to a green tint and were a little fuzzy.  Argh!  Intermittent problems are a pain!

But only within the symbols!  Crazy!  If it was the rear LCD itself it shouldn't be only within the symbols and shapes on the screen, I would think that anything on the screen would be affected if it was the LCD itself.

So I'm now suspecting it's the specific E4690 video card in there. 

This is a 625 brainbox that came with it, and the displays were connected to the on board video.   I had a few E4690 PCIe cards, so I installed that and connected the displays to it instead of the on board video ports.   For standard screen games, the on board video is more than enough.  I've even found that the on board video looks better for standard screen machines than installing the E4690 card and connecting the displays using that.  Not sure why as the E4690 is a better video card.  And the only one that can be used on AVP 3.0 boxes.

And even though most MLD games indicate on their PSR sheets that an E4690 video card is "required".  I've not experienced any issues by not using the E4690 add on video card on MLD's even when it's listed it as required.   But I still use them on my other MLD machines just because I have them.

So to try and isolate the problem, I pulled the E4690 card from the 625 brainbox and connected the displays to the on board video and it came up fine without any funny color issues or fuzzy video on the symbols displayed on the rear LCD screen.  But I didn't leave it running, so I'll fire it up and let it run all day today and see if the problem comes back.  If it's going to, it usually has happened within an hour or so and remains that way.  If all looks fine after running all day and and cycling through the games for about 6 hours.  Well that would be a pretty strong indication that the issue is the add on video card itself.   If it remains ok, I'll probably just leave it using the on board video.
 
If it does ever have a problem using the on board video, I have a few spare 660 brainboxes that don't have on board video, so they all have the E4690 cards in them that I can put in the machine if necessary.  Could even be something else in that 625 brainbox if it still happens.  But if all works ok, no reason to mess with it further.

Will see how it goes once it's heated up a bit from running.  Could even just be something that only happens after it heats up.  So replacing the fans and blowing it out could help as well if it happens again.  I'll be doing it anyway.

On the plus side (I guess).  I don't think this would be caused by a failing A/D board (if anyone reading this disagrees, please comment).  But from what I read the behavior is jumpy/scrambled video if it's the A/D board and mine doesn't do any of that.  Is if the rear LCD is messed up somehow.  I found a source for just the screens in the MLD display from other posts that's fairly recent.  Apparently they're both identical.  And it's quite reasonable to just get the LCD screen and replace it.  $100 for a brand new panel.  A refurb is $70, but if I'm going to take it all apart, I'd get a new one for $30 more.  Just have to remove the front LCD which is a pain but doable, and replace the rear LCD and put it back together.   If both were bad, even $200 is a good price to replace both with new ones if everything else is good on the display.

https://www.enlcd.com/p/ltm220mt05-lcd-panel/