Screen bright but image has disappeared

[chubsta]

I bought a Metal Slug machine today and everything was fine - it worked 100% at the guys house, and after transporting to mine, switched it on, everything worked great. I left the machine running a for a couple of hours and it was still good, but then suddenly the screen faded away until it is now just white - there is no image at all...

The machine still plays as it should, reels, sound etc, and there is power to the screen as it brightens up when power is switched on, so it seems a purely screen problem but having opened the unit up i dont really know where to start!

I have removed and reseated as many leads as i can but it appears the screen is well hidden behind a plastic cover and circuit board so am not really sure what bits are what - any advice would be gratefully received as it is in lovely condition and i cannot believe it has gone wrong so quickly!

thanks,
chubs

[chubsta]

A picture tells a thousand words...

[TilionMtl]

I would try to pull and reseat all connector. my Alien vs Predator did that once.

also, after you disconnect the machine for 2 or 3 hour (time to reset/cool down) did the problem seem to disappear and come back after some time? or it's there right when you turn on the machine after many hour not powered?

[chubsta]

Hi, thanks for the reply, i have left the machine off overnight and it is no better - the screen is bright but blank from switch-on.
As far as i can see i have taken off and reseated all the cables but will go through it all again this morning!

Any other advice much appreciated...

[chubsta]

As i seem to have reached a dead-end, anyone know anywhere in the UK that could possible repair it?

[daverob]

It's likely to be a connection between the LCD panel and the video CPU board controlling it, both of which are probably sealed in the same plastic box, so it will require some disassembly to get to.

If you need someone to take a look at it, your location would be useful to know, as you're going to be better off with someone local. Two lots of shipping charges plus any necessary repair costs would be likely to make it uneconomical. You might also find another local collector with a bit more repair experience who would be willing to take a look (as I would if you're not too far away from me).

[chubsta]

It's likely to be a connection between the LCD panel and the video CPU board controlling it, both of which are probably sealed in the same plastic box, so it will require some disassembly to get to.

If you need someone to take a look at it, your location would be useful to know, as you're going to be better off with someone local. Two lots of shipping charges plus any necessary repair costs would be likely to make it uneconomical. You might also find another local collector with a bit more repair experience who would be willing to take a look (as I would if you're not too far away from me).

Hi, I got As far as disconnecting everything and putting it back but didn't have the bottle to open up the plastic box containg the LCD screen! I'll have another go at it tomorrow.

It's good to know there is another collector not too far away though as I'm just along the coast near Folkestone - I actually picked the machine up yesterday from Eastbourne so was in your knack of the woods - coincidence or what?!

[chubsta]

Well i have just taken everything apart and cant see any problems - dead end for me. Are there any places that produce spares for these machines...

[chubsta]

Ive opened up the screen casing and removed the lcd, checked all connections/tracks etc and cant see any problems at all - am beginning to feel this one may be for the scrap-heap, a bit of a shame as its minty...

[troydogtvtv]

I am expert on lcd screens. But could you a a lcd and solder the cables to make it work with the machine. It would need to be the same size. If you go to a site like dealextreme.com they have some lcd's. Or could you take a digital photo frame apart and use that screen.

Like I said I do not know much about lcd's. But do know people use them to make home made projectors.

Also someone here has to know this. I seen a video where they took the video and ran it to a reg monitor before. Not sure how you would do this but I think it would be cooll to say mount a 14's lcd on top of the machine.

[SlotsRfun]

Because it happened soon after being moved I would agree with Daverob that it is a loosened connection. I think it would be somewheres betwen the LCD screen and the video cable (connection). Movement, shaking in transport, etc and also temperature changes from outside back to inside the house can loosen things!
Since you have removed and examined the screen itself with no change then you will need to look further away from the screen, examining the connectors all the way back to the video board.
Also it could be somewhere in the inverter circuitry but that would seem like too much of a coincidental failure to me but inverter trouble can cause blank white screens. Inverter trouble is often easy to spot, though so give the circuitry a look.

Oh I forgot to mention that moisture can also whiten a screen. Maybe your machine was cold and when you brought it in and condensation formed somwhere? Leave it open for a few days in a warm dry area to help dry it out. Maybe even have a fan blowing into it. Moisture troubles usually clear up within a few says and the machine starts working again.

[luckydog]

try moving it to another location

maybe the josling around will help??

[chubsta]

try moving it to another location

maybe the josling around will help??

Heh - i did try that, ive tried thumping it, smacking it from all angles - next step is to drop it off the White Cliffs at Dover - may not help the monitor but will make me feel better!

[chubsta]

Well, Ive worked on this problem some more and have made what i think is a significant discovery:

When switched on with the video cable disconnected from the lcd the screen is pure white straightaway.
When switched on with the cable connected there is an extremely faint image on the screen of the game data, which then fades quickly to pure white as the lcd 'warms up' - i had missed this previously as i attributed it to screen-burn. It also made me remember that when the image disappeared whilst the game was running when i first got it, it did not 'flick off' - it faded out to bright white.

This has led me to conclude the following:

The video board is working - otherwise i would get no image, let alone one that fades quickly
The cable between the video board and lcd is fine otherwise i would not see the difference in the screen between being booted with the cable out (pure white) or in (very faint image that quickly fades to pure white)
the lcd is getting power etc of it would just be black, and it is responding slightly when the cable is in.

Soooo, am i right in assuming the lcd is at fault here (certainly looks the most likely conclusion)?

And what can i do about it!? I have no 'spare' screen to try it with and dont know really where to look for one, google just brings up a million wholesalers in China!

The LCD model is

Samsung LTA104S2-L01.

I have attached a picture that shows what the screen looks like when the system is booted with the lcd cable connected - apologies for the poor quality image but its from my phone and the screen itself is incredibly faint at that point - you may however be able to see the faint image before it fades to pure white...

[daverob]

I was going to suggest that it looks like the contrast control has failed, but looking at a datasheet for that display panel, there isn't one. So my best guess would be a faulty LCD panel.

It might be an internal connection inside the panel itself, but dismantling an LCD panel is best left for a last resort - nothing left to lose situation unless you really know what your doing in there.

[joyousjake]

I didnt realise how much these panels are!!

Samsung LTA104S1-L01 10.4" LCD Panel - eBay (item 390143062064 end time Dec-09-10 13:06:33 PST)

[Drunkenclam]

you really need to know what else these panels when fitted too, To get a used one cheaper, But no idea how.

[chubsta]

I was going to sell it on Ebay but there was no interest so have decided to hold onto it for the forseeable future. I see there being 2 possible solutions - i check once a week on ebay for a replacement screen (everything turns up on ebay eventually!), or i try to use a different lcd panel.

The 2nd option seems the most likely but this one uses a small ribbon connector and all the ones i see around have a dvi-type inoput. Perhaps i may be able to find somewhere that could rig a new cable for me as i am sure the pin-outs on the video board would be quite standard - any think this could work out?

[Drunkenclam]

Some times it does pay to check ebay regular. I finally found a replacement motherboard for my laptop on ebay, But I did have to search for 4 months.
What is the connection from the ribbon cable onto the video board? and monitor, Just the press fit type. Best keep an eye out. I would have no idea if you could get a different panel to work

[troydogtvtv]

i still wonder if a digital photo frame lcd would work or one from a portable dvd player.