Electrohome Go7 CBO Has HV Good B+ No Image

[jjhudgins]

New to me:

New Caps
New FB
sync Mod

Symptom NO Image
I have HV, Neck Glow and Perfect B+
Reflowed ALOT including video pins and neckboard plug

What to look for?

 

[tron guy]

Was it working prior to you working on it, or unknown?

Test DC voltages on the neck board. I don't have them memorized, but I have notes. I think I measured all 8 or 9 points that the socket is soldered into the neckboard. Write down the DC voltages at each point.

I've had this problem, with these symptoms with a bad focus block.

 

[jjhudgins]

Unknown working condition before I recapped it.
Are we thinking neckboard here?

 

[tron guy]

Neckboard is where I am asking you for voltage measurements. Bad focus block is my first thought.

I want to say I've had this issue before as well when the HOT was installed backwards. All good voltages, no image. That's why I'm asking for the neckboard measurements.

 

[RobotWorkshop]

Are you sure what is driving the monitor is putting out a signal? Cracked solder connections at the input header on the PCB? Connector unplugged?

 

[jjhudgins]

Yeah reflow was done and traced out on my meter. My tpg is fine

 

[jjhudgins]

Neckboard is where I am asking you for voltage measurements. Bad focus block is my first thought.

I want to say I've had this issue before as well when the HOT was installed backwards. All good voltages, no image. That's why I'm asking for the neckboard measurements.

G1 zero

Gk 150

G2 8

Rk 150

H9 59

H10 59

Bk 104

 

[jjhudgins]

Neckboard is where I am asking you for voltage measurements. Bad focus block is my first thought.

I want to say I've had this issue before as well when the HOT was installed backwards. All good voltages, no image. That's why I'm asking for the neckboard measurements.

So I measured ohms on the focus block putting my black meter on the chassis ground and the red on the yellow wire. I measure 1.5 to 1 Mega Ohms. When I turn it up the Mega Ohms get smaller (decreases)

On a good chassis I measure 2.5 to 9.5
When I turn it up the value increases on the good one.

 

[tron guy]

Try swapping the focus blocks. I need to go find my notes, but something should measure over 500vdc iirc.

 

[jjhudgins]

I have to find one. I swapped it with a working one and now it works.

 

[jjhudgins]

Found another GO7 with a bad focus block. It was smoking thru the pot. 2 in one month