No red in picture?

[bloodyviking77]

I discharged the tube, disconnected neckboard and chassis and removed from my cab (to try out a new vga monitor I got - that didn't work - another story )

When I re-installed the tube and reconnected the neckboard, it seemed pretty "tight" and I had to wiggle it quite a bit to get it sitting "right". When I fired up the tube again, it seems to have lost all red colour. The picture is fine otherwise, but has a distinctly blue/green cast.

Twiddling the blue/green drive pots on the neckboard will change the degree of blueness or greenness, but twiddling the red pot has zero effect.

I fear I may have cracked a trace or broken a connection on the neckboard while wiggling it back on to the tube. See pic attached - looks to me like this might have happened before?

Anyone have any suggestions on where to start checking?

[Ken Layton]

Yep, that neckboard has been broken before. 

I can see where jumper wires have been tack soldered over some breaks.

[bloodyviking77]

Thanks Ken, thought so!!

so i guess i just check all the connections and re-solder where broken? Should I remove the cr**py looking solder and start again?

[Ken Layton]

It wouldn't hurt to resolder.

[bloodyviking77]

I've re-soldered the old repairs and gone over the whole neckboard and can't seem to locate any other breaks. I have checked using a multimeter and have continuity between all points I have tested.

However, on hooking her back up, picture is as before - I still get no red!!

Anything I should check in particular? Caps?

I'm pretty much a newb at this - I'd sure appreciate a few pointers!

[dabone]

I had a problem like that with a g07, turned out I had cracked the solder joint on the input pin for the red gun.

I spent 2 hours going over that neck board until I had my homer simpson moment.

DOH!!!!!

(So did you try resoldering your input connector???)

Later,
dabone

[fredster]

Could you have shorted one of the big transistors on that neck board? They are the important ones for generating color.

I have a 4600 that I can't get red in.  Went all over the back of it and even replaced the transistors and still no blue.

I had a g07 too that I fixed by jumping the traces to make sure they were good and it fixed it.

[MonitorGuru]

I discharged the tube, disconnected neckboard and chassis and removed from my cab (to try out a new vga monitor I got - that didn't work - another story )

Why the heck did you do all that to remove the monitor from the cabinet?

[bloodyviking77]

Why the heck did you do all that to remove the monitor from the cabinet?  Unless you left the frame in, in order to hold a new bare VGA monitor, that was your first error.

the reason I had to disconnect the lot is that the monitor has no frame: my cab has the monitor "ears" mounted direct to a slab of ply, and the chassis is bolted straight  to the inside of the cab. I was swapping out the old monitor to try a vga one that didn't work (it was too big to fit properly - the neckboard stuck out the back of the cab about four inches).

The stoopedist part is after spending a week of evenings mucking about with re-flowing solder joints on the neckboard and re-checking all the old repairs, I took a look tonight at the pins on the neck, and what do you know, one of them (just out of sight behind the neck when the tube was mounted) was bent to buggery.

Straightened her up with a pair of pliers and what do you know? perfect picture!!.

At least I know the neckboard's in good nick