PC monitor blank screen!But glow in the yoke (pics)

[Wetworks]

I bought this monitor the other day quite cheap ($50.00 aus) It was working fine ! Its a 21 inch Phillips PC monitor. Setup dosmame with an ol pc and had it working fine! So to put in a cab I had lying around I had to decase it to make some monitor supports. So here is where the problem starts!

1. When I hooked it up I plugged the R G B and H V backwards..Did this cause the monitor to die??(have hooked up correctly since)

2. There is a glow in the neck plug ( so I am getting power)

3. It makes a static kind of noise like its emitting picture

4. I have checked my cables and hooked the PC  up to another monitor and it works fine!

5. I have tweaked the brightness and contrast and it doesn't do anything to the screen

6. There is no indication of any type of screen image just dead black.



What should I look for? All connectors are intact? Any help ! Or I have I blown my weekend and $50.00 bucks??

[Wetworks]

Blah 
I don't think I will be able to fix this! more blah 
Searched the net and keep finding take it a to service repair person . more 
Pissed off off cause I know it will be something simple..more blah
Oh well off to bed to ..well blah
F@#$ing Monitors!!!

[SirPeale]

Are you running it out of spec?  IE running it at a resolution the monitor can't handle?

[grantspain]

quick check to do-turn up your screen volts on your lopti to see if you have a white screen,this will prove if its signal or monitor,also usually there is a LM1308N chip on the neck card,if this blows you get everything apart from a picture.

[Wetworks]

Hi thanks for the replies!
Ok turned up the screen volts on the lopti and I have a white screen. So does this mean its signal?


edit I am only using 640x480 resolution had it set to 800 x 600 but it made no difference. It worked before I decased it.

[SirPeale]

Is the cable plugged in securely?

[Wetworks]

I assume you mean the monitor cable to the PC and yes it is checked it over and over. Switched back to another monitor and picture is there! So it's not the PC or output from the PC.

But as I was looking over the monitor I found  the vertical adjustment pot is broken. Could this cause me to lose picture all together? Are they easy to replace ( I asssume you don't have to discharge the monitor to solder here right or wrong?) Where do you buy them? How do you test them? Sorry for all the questions but I don't want to stuff this ( which I think I already have)

[grantspain]

that broken pot won't cause loss of picture,what you should be looking for is a cable disconnected,usually on pc monitors you have svga plug from pc that goes to the neck board/monitor,follow that cable,when you decased the monitor you may have disturbed a cable.

[Wetworks]

Would these be the Red Green Blue cables (pic 1) that go into the neck board?
It has seperate plugs for each (pic2)

[grantspain]

yes that looks correct,but between picture 1 and 2 those cables must go somewhere,you may have to take that metal plate off to have a look,also check your cable continuity just incase a cable is broken inside also check for dry joints.
I worked on a house of the dead the other day setting up the convergence,lost the picture and it was a bad connection in the sinc cable.its gonna be something simple.

[Wetworks]

Thanks for the help grantspain!
Taken the metal plate off and it shows where the RGB plugs in at the top .These then go to the neckboard.

I checked for continuity from the cable inputs to the neckboard. Seems fine. I also checked from red to blue etc and have continuity here also. Should this be the case?

[grantspain]

what i'm more interested in is the continuity between your bnc connectors and your svga plug because thats where i think the fault lies,otherwise something on the signal input board is malfunctioning either dry joint or componant failure.

[Wetworks]

Ok so I just test continuity from svga plug (the one that goes into the video card) to the end of the cable ( the bnc connectors)
This guide should be ok ?
Thanks for your help with this one.

[grantspain]

yes to the first statement,the picture of vga is correct but sometimes each of your colours will have its own seperate ground,those cables going into your monitor maybe a signal wire with a ground/shield as well, for instance the red cable has one central wire which is the red signal and then another wire or shield which the red ground(but not always)-what im trying to say is your red should read continuity from the vga to bnc then the metal plug casing of the bnc should read continuity to red ground/common

[Wetworks]

Well decided to another crack at this. I hate getting beaten by anything.

yes to the first statement,the picture of vga is correct but sometimes each of your colours will have its own seperate ground,those cables going into your monitor maybe a signal wire with a ground/shield as well, for instance the red cable has one central wire which is the red signal and then another wire or shield which the red ground(but not always)-what im trying to say is your red should read continuity from the vga to bnc then the metal plug casing of the bnc should read continuity to red ground/common

Checked the continuity from the vga to bnc and ground to outer case all seems good. It has a seperatate ground wire on the vga plug which connects to the monitor frame. Brightness and other adjustments seem to work . If anything I might of bumped the end of the neck board against the RGB input board. But have checked all traces, solder joints and components and they seem intact. (Still have the glow in the neck. Removed neck board and seems ok. 
Where is the LM1308N chip located?
Are there any fuses that may of blown?
If I took a PC monitor to a repairer that has been decased would they still try to repair it?
Should I just give up?
Thanks

[grantspain]

well i have nearly exhausted all my suggestions,but i noticed your rgb decoder pcb has a two wire power in cable on the top,maybe meter how many volts you have on that(i would expect 12 or 5 volts for the logic).does the other cable go to your adjustment control panel?

[Wetworks]

Is the two wire power cord the white one it has three actually ( doesn't show up in pic well ) it runs to the control panel as well as the other cable. I think this is where it gets its power from ie power to control panel then to rgb encoder. The control panel is the only component not mounted to the metal frame ( and the monitor ) should this be grounded ?

[grantspain]

i don't think that panel would need grounding,but i am very interested where the rgb decoder pcb gets its power from-i think you gonna have to get a meter on those wires see what you get,at the docoder board that is(im kinda thinking about any breaks in the voltage supply)