D9200 lines on screen in lower half

[Nexus13]

Hey all,

I'm having some issues getting this D9200 from a buck hunter going again.  It originally showed a dark line across the center of the screen with a kinda jittery image.  After leaving it on for a bit, it progressed to more lines across the lower half of the screen.  I've read the service bulletin about the usual suspects:  C308, C306, C314 and all of them tested fine.  I also tested C847 which feed voltage to the IC301 section and it also tested fine.  I started digging deeper.

was getting 15.7VDC coming in from secondary side of transformer - looks good.  also getting 163VDC on the one side of R324.

Now R317 is kinda weird.  In its place is a 10k 1/2 watt resistor and the schematic calls for a 1 ohm resistor.  THe banding on the resistor is for a 10k and it shows no signs of distress.    I get like 0.6 VDC on the one side of R317.  Not sure where this is supposed to go or what its purpose is. 

Anyways, I was hoping to figure this one out without the shotgun approach of replacing all the caps.  Any tips on where I should look next?

Thanks in advance!

[lilshawn]

I had a very similar thing happen. blasted the area in front of IC301 with freeze spray and it would go back to normal.

I ended up replacing all the capacitors (even though they tested okay) and resistors (even though they looked okay) all in front of IC301 as well as IC301.

AFAIK it hasn't done it again (it's in a machine that went out)

EDIT:

not sure what the deal with your weird resistor value is.

[Nexus13]

Hey Shawn!

Thanks for the advice! Yah I tried cold spraying it but no change.   I'm just gonna order a new IC and put the new caps in to see if that fixes the issue.  Fingers crossed.

[lilshawn]

yeah IC301 handles the vertical deflection, so basically any of the tuning items in that area could be responsible for it.

i wasn't sure which part exactly was the culprit, I ended up changing 3 or 4 of the dipped ceramic/mylar caps and a half dozen resistors... maybe a diode or 2 to just shotgun blast the whole area. not something i normally do, but i'd already spent way too long on it. i'd already swapped out the ic, but did it again, just to be sure (and I had a 25 pack of them, as they go all the time)

[Nexus13]

Hmm yah I've got my shotgun loaded now - aiming for the heart.  I've put the new vertical IC in and a couple of caps and no change.  *Sigh* .   I'll try replacing the small mylar caps and some resistors to see if that changes anything... such a weird one.