Peale
Active member
Stop whatever you're doing right now and post a photo of the trace that blew.
K7000 rainbow
- Thread starter jay
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jay
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RetroHacker
Well-known member
Have you ohmed out the yoke on the picture tube yet? If you're trying to put a 7000 chassis on a yoke that's *not* from a 7000, it's no wonder it doesn't work. Of course, you really should have blown something up sooner if that were the case... Measure the resistance of this yoke and compare it to the one in your Hard Drivin.
-Ian
-Ian
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jay
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The thing is both of the monitors came with 7000's in them with stickers on the frame of the tubes identifying the chassis as k7000's.
I understand things get changed out, but damn, it looks like these were really 7000's. Having the same issue (rainbow) on 2 totally different monitors with the same chassis, then putting a known good chassis in and blowing a trace? I'm lost
I understand things get changed out, but damn, it looks like these were really 7000's. Having the same issue (rainbow) on 2 totally different monitors with the same chassis, then putting a known good chassis in and blowing a trace? I'm lost
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RetroHacker
Well-known member
OK, I thought you weren't sure that the tubes/yokes were 7000 or not.
Well, the blown trace could be something else. If you didn't get the chassis properly seated and it touched the frame, it could easily short something out. Or, if you left a lead too long and it bent over... A lot of possibilities. I just don't know all the specifics of what you're working with, so it's hard to tell.
-Ian
Well, the blown trace could be something else. If you didn't get the chassis properly seated and it touched the frame, it could easily short something out. Or, if you left a lead too long and it bent over... A lot of possibilities. I just don't know all the specifics of what you're working with, so it's hard to tell.
-Ian
Arm123
Member
I know this doenst help you now, but you should always ohm out the yoke before a chassis swap...
RetroHacker
Well-known member
The same series of chassis are not always 100% interchangable. For example, there are two differen yokes used throughout the 4600's. I'm not sure about the 7000's though.
-Ian
-Ian
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jay
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I mean the EXACT same chassis it came with. Put it into my Hard drivin, worked, capped it and the such, put it back into HD, worked. Then, put it back in the original frame with original tube, and blown trace.
Oryk Zinyo
Well-known member
It sounds like something shorted. You should go over the chassis again and verify that you cut all of the legs off of any newly installed components and that there is nothing under the chassis that may have caused it to short.
What trace burned?
RetroHacker
Well-known member
Well, then, the yoke could be damaged/shorted, or you could have put the chassis in just crooked enough to short out some trace against the frame... anything is possible.
It's just that the "odd rainbow" effect you were getting before is very remeniscent of having the wrong yoke connected.
I'll have to go back and re-read this whole thread... you have swapped chassis/tubes around enough that I don't know what's related to what anymore.
-Ian
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jay
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LOL, I know. I'm almost there
And hey guys, thanks for stickin with me through this and giving suggestions. I'm very thankful.
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jay
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There's a pic a page or 2 back. It runs above the fuse. Hoping I can bridge it with wire???
Arm123
Member
you could still meter the yokes... that would rule out a chassis mismatch problem.
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jay
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That is a something I've been pondering because I really did take extra care when connecting the chassis.
When the board is in the Hard drivin, it's vertical and no metal under it. In the Mace cab it's horizontal with a metal frame under it.
If you look at the pic of the blown trace, you can see "black char" marks in the middle of the chassis (point of contact?). I also found black marks on the plastic "pcb holder" at the exact same place on the frame where the pcb slides in.
Now, I've tried soldering traces together before (4900 broken neckboard thread, thanks again Cliffo!!!!) but, I had a very hard time getting the solder to stick. Any tips on soldering without pads????
Will "ohm out" the yoke tomorrow. However, I'm at a loss on how to properly perform this procedure. Where the hell do I exactly put the probes???? And once I get the numbers...What on the chassis determines if it will work with that yoke??
Thanks again
Oryk Zinyo
Well-known member
The char marks look to me almost like the head of a screw was in that location and shorted those two traces together.
I wouldn't try soldering that peeled trace back to the other side of the trace. I would just replace it with a jumper wire. I think that is the ground plane so I would use a larger wire for this particular jumper, 20 or 22 gauge.
When I try to solder anything to a clean, copper only trace I always use a large amount of liquid flux to help with the heat transfer. Also, you should go ahead and tin the trace before attempting to complete the solder joint.
You need to take your leads and connect across the blue and red wires coming from the yoke and check resistance. Record that number and then do the same with the other two wires (green and yellow). The K7000 standard resistance is pretty well known, I think it is somewhere around 8 ohms and 2 ohms but I need to verify that against a chart I have at home.
KevinMullins
Active member
Isn't Hard Drivin' a medium resolution game ?
