What's causing this?

[Devryn]

O.K. Here's the thing. Modessitt fixed my chassis (it worked great), and like a tool, when I put it back in the cab, I forgot the anode cap. I replaced the diodes D20 and D21 with 1N4005. I replaced the VR and HOT with NTE 2302 & 1742. Now I get this:

http://s221.photobucket.com/albums/dd275/Devryn/Neo Geo/?action=view&current=VID_20110221_181404.mp4

Any ideas?

 

[cadillacman]

man that sucks!!!


what monitor is this a k7000???

if so suspect the ics, if youve ensured you have the video wires hooked up correctly and are sure you have the holds as good as they get.


The last k7000 i had with a ground off( same thing basically arcing and sparking) it took out one of the video ics i think ic2 or ic3...


Best of luck. that sucks man!!

 

[kstillin]

Looks like the horizontal frequency is WAY off.
The sync signals keep it lined up normally, but if the frequency is too far from normal, the sync won't help. Try adjusting the horizontal frequency.

 

[Devryn]

man that sucks!!!


what monitor is this a k7000???

if so suspect the ics, if youve ensured you have the video wires hooked up correctly and are sure you have the holds as good as they get.


The last k7000 i had with a ground off( same thing basically arcing and sparking) it took out one of the video ics i think ic2 or ic3...


Best of luck. that sucks man!!

this is all very new for me. What is an ics and how can I test it? Any idea if its something I can pick up from radioshack or frys?

 

[THE COUNT]

IC's are integrated circuits. IC1 and IC2 are the "chip" looking ICs near the middle of the chassis. IC4 is your voltage regulator and IC3 is part of the vertical control. You will not find them at a local electronics store, that I know of.

 

[Devryn]

IC's are integrated circuits. IC1 and IC2 are the "chip" looking ICs near the middle of the chassis. IC4 is your voltage regulator and IC3 is part of the vertical control. You will not find them at a local electronics store, that I know of.

I got the vr at frys. Any part numbers or anything? Nte seems to be readily available at frys

 

[THE COUNT]

The last IC3 I replaced was a LA7831. IC3 will cause vertical collapse, which is almost what looks like yours is doing at about the 5 second point in your video. Not sure though, since what is happening before the 5 second point is totally different.

 

[Devryn]

The last IC3 I replaced was a LA7831. IC3 will cause vertical collapse, which is almost what looks like yours is doing at about the 5 second point in your video. Not sure though, since what is happening before the 5 second point is totally different.

Was that in a K7000? Did you get the number from the chip?

 

[THE COUNT]

Yes that was a 25" K7000. That is the no. for the replacement for IC3 from Bob Roberts. The NTE no. for it is NTE1797.

 

[Devryn]

Yes that was a 25" K7000. That is the no. for the replacement for IC3 from Bob Roberts. The NTE no. for it is NTE1797.

What about IC1? Does that typically go bad?

 

[THE COUNT]

I have never replaced an IC1 or IC2.

 

[KevinMullins]

Was that in a K7000? Did you get the number from the chip?

You need to get the number from YOUR chip. (IC3)

There are a couple different variations that have been used on K7000's.
Like an LA7831, LA7833, UPC1378, AN5515, etc, etc.
And you haven't specified enough here about your chassis to distinguish which version YOURS might have in it.

Don't sweat IC1 or IC2 just yet.
IC3.....the one on the little standalone heatsink on the right side towards the rear is usually the culprit for vertical collapse. (if nothing else in the circuit got damaged)

 

[THE COUNT]

You need to get the number from YOUR chip. (IC3)

There are a couple different variations that have been used on K7000's.
Like an LA7831, LA7833, UPC1378, AN5515, etc, etc.
And you haven't specified enough here about your chassis to distinguish which version YOURS might have in it.

Yeah, sorry I didn't make that clearer either. That's why I said the "last one" I ordered was a LA7831, it's the only one I still have the email to Bob ordering one in my sent folder.

If you are going to replace IC3, you might as well check R91 for a possible open condition.

 

[Devryn]

Yeah, sorry I didn't make that clearer either. That's why I said the "last one" I ordered was a LA7831, it's the only one I still have the email to Bob ordering one in my sent folder.

If you are going to replace IC3, you might as well check R91 for a possible open condition.

Will do. Thank you. My numbers matched yours. I ordered both tonight (so I don't have to pay shipping twice...Just in case)