G07 CBO - Vert Deflection

[eh97ac]

G07 CBO - Vert Collapse

**************There is no fix in this thread***********************+

So I have vertical deflection on 1 of my chassis.

I would rather resolve this faster than save a few bucks. Can someone list off the parts needed to fix this?

BTW - I have confirmed the yoke is good.

 

[Dokert]

Whaaaattttt?

Do you mean that you have vertical collapse? or what? I don't understand the problem.

 

[eh97ac]

1 line in the middle, running from top to bottom of the screen. The screen is mounted vertically

Do I have the term wrong?

I reflowed all suspect 400 series cold solder points to no avail.

 

[eh97ac]

BTW - I did a complete Bob Roberts deluxe kit before posting

 

[Dokert]

1 line in the middle, running from top to bottom of the screen. The screen is mounted vertically

Do I have the term wrong?

I reflowed all suspect 400 series cold solder points to no avail.

Yes, you have term incorrect. You have vertical collapse. Reflow the vertical transistors and look for hairline cracks around both vertical transistors on the solder side of the chassis.

 

[eh97ac]

reflowed X901, X902, R908, R906, R912, R913 and a bunch of others.

Still have the line.

I have found the NTE #'s for 901 & 902, can anybody cross ref R908 (QRV22F-4702)

 

[Dokert]

X401 & X402 is what you need to look at

 

[eh97ac]

X401 & X402 is what you need to look at

I replace these and the line still persists.

 

[modessitt]

You have the brown and gray yoke wires on pins 3 and 5?

 

[eh97ac]

You have the brown and gray yoke wires on pins 3 and 5?

Correct, gray on 3 and brown on 5

 

[modessitt]

Well, then, start going through your 400's. Check FR401 first...

 

[Homepin]

Do you have voltage on the transistors? they are normally fed from THE B+ via a fusable resistor.

No voltage = no deflection.

 

[eh97ac]

Well, then, start going through your 400's. Check FR401 first...

Will do! Is there any specific reading to look for or look out for?

 

[modessitt]

Value should be written on the part...

 

[eh97ac]

FR401 I got 68.5 Ohms and 2.3 V

 

[modessitt]

Well, follow the schematic and check the 400's. Make sure you're getting V-AMP out of the IC, and trace the voltage through the circuit.

It's also common to have some tiny cracks in the chassis from stress around the flyback. You might have a broken trace there around the yoke connector...

 

[eh97ac]

I wish I would have taken physics instead of biology in high school!

 

[eh97ac]

R906 Brown, Green, Yellow and ?? I cannot figure out the last band on either of the two boards I have. 150K ?%

I am replacing it as I can see a burn mark around one of the legs

 

[eh97ac]

Make sure you're getting V-AMP out of the IC, and trace the voltage through the circuit.

As you have guessed by now, I am not an electronics expert. Can you explain how to perform the above test?

 

[eh97ac]

Replaced a bunch of parts and now things have change (better or worse, I do not know)

Parts replaced
X901 902 701 501 402 401
R906 908 904 905 910
FR901 401
Bob Roberts Deluxe Kit

Now when I power it up, I have nothing on the screen and the B1 on either end is about 165V?

Any ideas?