Teknotoyz
Well-known member
Well, got a good deal on a cabinet with a dead monitor.
Monitor is a 25" K7000 with a blown fuse.
So I pulled a newbie screw up and put a 3 amp fuse in (2 amp normal) to see if there was any life... Magic smoke was released from the area of the rectifier diodes.
After removing the neck board, the plastic key is missing from the tube, but pins are straight and all there so I assume the board was installed correctly, stole one off another tube for now.
OK, so NOW I looked online and found the monitor flow chart, Bob Roberts info, and Aaron's sticky on the K7000 and learned a bit of knowledge before making more issues for myself.
As it turns out, I also have a 19" K7000 I will need to rebuild, also dead.
Time to become schooled.
I have ordered replacement parts from Bob Roberts:
-1N4007 diodes for the rectifier section.
-2.7ohm 7 watt resistor
-Voltage regulator
-Flyback (only ordered 1)
-Cap kit
-HOT (1398) IC
Details (both are K7000, I'll call them by the tube size):
No fuse on the 19 and blown fuse on the 25
The HOT measures bad on both chassis's (low resistance from chassis to center pin).
The 19 has the flyback with the white knobs Aaron seems to love.
Both the 2.7ohm 7 watt resistors are measuring around 3.4ohms
So what do I do first?
I know I have to replace the HOT on both the 19 & 25.
If the flybacks appear physically OK, do I try them?
Aaron recomends replacing the white knob flyback regardless.
How do you know the voltage regulator is good or bad?
Is there any way to test the rectifier diodes IN the circuit?
I measured continuity, but get a 211kohm reading on both ways across all the diodes on 19&25.
There is no visible magic smoke source, so I'm pretty worried about the diodes.
I'd like to start with the known bad items, like the cap kits and HOT's. But I don't want to have another bad component kill the new ones.
Can anyone give me some advice on what to do?
I've never had to replace a flyback before, sounds like HOT's get taken out often with them.
Monitor is a 25" K7000 with a blown fuse.
So I pulled a newbie screw up and put a 3 amp fuse in (2 amp normal) to see if there was any life... Magic smoke was released from the area of the rectifier diodes.
After removing the neck board, the plastic key is missing from the tube, but pins are straight and all there so I assume the board was installed correctly, stole one off another tube for now.
OK, so NOW I looked online and found the monitor flow chart, Bob Roberts info, and Aaron's sticky on the K7000 and learned a bit of knowledge before making more issues for myself.
As it turns out, I also have a 19" K7000 I will need to rebuild, also dead.
Time to become schooled.
I have ordered replacement parts from Bob Roberts:
-1N4007 diodes for the rectifier section.
-2.7ohm 7 watt resistor
-Voltage regulator
-Flyback (only ordered 1)
-Cap kit
-HOT (1398) IC
Details (both are K7000, I'll call them by the tube size):
No fuse on the 19 and blown fuse on the 25
The HOT measures bad on both chassis's (low resistance from chassis to center pin).
The 19 has the flyback with the white knobs Aaron seems to love.
Both the 2.7ohm 7 watt resistors are measuring around 3.4ohms
So what do I do first?
I know I have to replace the HOT on both the 19 & 25.
If the flybacks appear physically OK, do I try them?
Aaron recomends replacing the white knob flyback regardless.
How do you know the voltage regulator is good or bad?
Is there any way to test the rectifier diodes IN the circuit?
I measured continuity, but get a 211kohm reading on both ways across all the diodes on 19&25.
There is no visible magic smoke source, so I'm pretty worried about the diodes.
I'd like to start with the known bad items, like the cap kits and HOT's. But I don't want to have another bad component kill the new ones.
Can anyone give me some advice on what to do?
I've never had to replace a flyback before, sounds like HOT's get taken out often with them.
