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Main => Main Forum => Topic started by: gajaman on February 13, 2008, 08:42:53 am

Title: Small Bartop Screen Issues
Post by: gajaman on February 13, 2008, 08:42:53 am
I'be been absent from the arcade scene for a while (with the exception of playing the Gajacab!) so I decided to build a bartop cabinet using an old PC and 15" Dell flat screen monitor to "keep my hand in".

I'm really pleased with the project and all is good, except, I am getting intermittent screen flickering. I've been testing to try and isolate the cause but have yet come to no conclusion, heres what I know:

For info the mother board and hard drive are effectively mounted on the rear of the screen chassis with the PSU just below (I'll post some pictures later).

There appear to be no loose connections and jiggiling stuff around inside makes no difference.
I can use the cabinet for as much as two or three hours with no flickering, sometimes it flickers after 30 minutes.
The flickering makes the whole screen go lighter with horizontal lines about 10mm thick that travel down the screen, the pattern flicks on and back to normal with varying frequency.
It looks like electrical interference to me, but the fact it's inconsistent makes me think it might be heat related?

Any suggestions gratefully received.
Title: Re: Small Bartop Screen Issues
Post by: Daniel B. on February 13, 2008, 08:57:08 am
Can the back be removed? A simple test to find out if it is indeed heat related, would be to open up the back or side panel and point a fan in there.
Title: Re: Small Bartop Screen Issues
Post by: gajaman on February 13, 2008, 08:59:19 am
Hi Daniel,

The back can be removed, I hadn't thought of blasting a desk fan at it.

I'll give it a try and see if it makes any difference.

Thanks
Title: Re: Small Bartop Screen Issues *pic added*
Post by: gajaman on February 13, 2008, 01:24:15 pm
Just for information heres a picture of the cab -

(http://img.photobucket.com/albums/v690/gajafirenza/GajaBlack1.jpg)

Its a smidge under 350mm wide (14"). The screen colour looks awful in the picture but it's just the camera.
Title: Re: Small Bartop Screen Issues
Post by: Daniel B. on February 13, 2008, 01:25:07 pm
That thing is awesome!

did you have a build thread?
Title: Re: Small Bartop Screen Issues
Post by: gajaman on February 14, 2008, 03:13:39 am
Thanks Daniel, I'm pretty pleased with it.

No, I didn't have a thread going for the build beacuse I've built controls and a cab before, I just scaled things down a bit.

I started the project half with the idea of maybe making ten or so and trying to sell them as a budget base unit for emulation/classic games playing. The reality is that with the cost of the PC, screen and a windows licence coupled with the time the build took it wouldn't be a very budget product! Also it weighs loads, the shipping would be killer!

I did some "testing" last night (well, I played Speed Rumbler for a while). The unit was on for an hour and 15 minutes before the flickering commenced, but after 2 or 3 minutes it stopped and didn't reoccur in the next 25 minutes when I switched off. Makes me wonder about the heat, surely if the problem were caused by heat it wouldn't stop for so long as the unit wasn't getting any cooler?

Maybe the screen is defective?
Title: Re: Small Bartop Screen Issues
Post by: Lilwolf on February 14, 2008, 08:34:43 am
I've seen this on my wifes old notebook.  VERY similar sounding to me.  I ended up buying her a new notebook (it was time anyway). 

But some questions.  Is the screen still there, but the back lighting turning off? 

Can you remove the screen and have it just sit next to the cab?  I dont' know if it will help, but It might give you some ideas.

I'm guessing that its power to the monitor.  thats seperate unit right?  Is that exposed?

Good luck.  But I would consider looking around on ebay or friends.  15" lcds are cheap these days.   
Title: Re: Small Bartop Screen Issues
Post by: surface tension on February 14, 2008, 08:50:46 am
You need to isolate the problem first. It's going to be one of; the LCD, power supply, driver electronics, inverter or graphics card.

The easiest thing to isolate first would be the graphics card.

Nice cab by the way. What size motherboard do you have in there, one of those micro things?
Title: Re: Small Bartop Screen Issues
Post by: gajaman on February 14, 2008, 03:54:09 pm
The mother board is a standard size, just a spare pc I had sitting doing nothing, it's a tight old fit. I'll add some pics of the insides when I get a minute.

I do have a spare flat screen that is identical, maybe I need to swap this out. I could then run the (poss) defective screen off of another PC and see what I get out of it.  Problem is to swap out the screen I need to dismantle the whole cab and all of the sub-assemblies within, a bit of a pain. I still haven't done the "fan blast" testing suggested by Daniel, maybe I should try that first?

Title: Re: Small Bartop Screen Issues
Post by: mountain on February 14, 2008, 03:59:49 pm
Nice bartop! I have kicked around the idea of building and all gloss black bartop with chrome accents for a while now. Post some more pics when you get a chance!
Title: Re: Small Bartop Screen Issues
Post by: DeLuSioNal29 on February 14, 2008, 05:11:20 pm
Here's an easier way to isolate the problem to see if it's a defective monitor or not without having to tear apart your system and remove video cards, etc.

Simply unplug the monitor and plug in another one from outside the case.  Try it and if the problem you describe persists, then you know it's NOT the monitor itself and that it's a problem with the other components.

It doesn't make sense to start removing stuff from the comp itself just yet until you are sure it's not the monitor.

~ DeLuSioNaL
Title: Re: Small Bartop Screen Issues
Post by: gajaman on February 17, 2008, 11:42:20 am
I've posted some more pics in a thread in the announcements forum:

http://forum.arcadecontrols.com/index.php?topic=76777.0 (http://forum.arcadecontrols.com/index.php?topic=76777.0)
Title: Re: Small Bartop Screen Issues
Post by: Jess-- on February 17, 2008, 07:57:32 pm
just a silly suggestion here

did you have your mobile phone close when you got the bars and flickering, I have seen similar things with unscreened video leads when mobile phones get accessed
Title: Re: Small Bartop Screen Issues
Post by: protokatie on February 17, 2008, 08:22:20 pm
Quote
did you have your mobile phone close when you got the bars and flickering, I have seen similar things with unscreened video leads when mobile phones get accessed


HAHAHA! OMG! Before I scrolled down this far I was going to suggest the same thing! Cellphones can make screens (and even speakers) do odd things!

I now NEVER have my cellphone near my computer, as it will on occassion (when probing for nearby towers) cause the screen to flicker/buzz and cause the speakers to make wierd clicking and buzzing sounds...
Title: Re: Small Bartop Screen Issues
Post by: mountain on February 17, 2008, 09:07:35 pm
Yeah, I have a Samsung Blackjack and when it tries to sync with the server it makes my speakers buzz like crazy. Every computer in the house starts buzzing, very annoying.
Title: Re: Small Bartop Screen Issues
Post by: DeLuSioNal29 on February 17, 2008, 09:26:38 pm
Yeah, I have a Samsung Blackjack and when it tries to sync with the server it makes my speakers buzz like crazy. Every computer in the house starts buzzing, very annoying.
Imagine what it's doing to your brain when you answer it!
Title: Re: Small Bartop Screen Issues
Post by: gajaman on February 18, 2008, 02:27:38 am
No mobile phone link I'm afraid. My phone was nowhere near.

I had the unit on for about four hours last night just on attract mode in a few games - nothing. Now thinking the vibration from playing might be doing something, problem is, I can't consistently replicate it -argh!

Guess I'll just have to keep playing, er, testing.