G07 tech help needed.

mochaman

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Have 2 G07's that are acting the same. I used the Flowchart from Fromme and I get to the "call for help" box. No pic, no glow. Fuses good. Caps new. 1 has new fly. Running about 160vdc, non-adjustable. Any ideas on what might be the issue? Thanks in advance.
 
did you pull the X701 and see if it fires up??? did you check the 900 section resistors? R908 and R912 i think are the two most common bad ones i have personally come across.
 
If you have 160 volts and removing X701 didn't power up the chassis there is no need to check the 900's. You have a horizontal deflection circuit problem.

Check for broken traces or cold solder joints around the flyback on the chassis with the new flyback. If every thing looks good there double check X501 and the HOT. Then as a last resort replace IC501. Be sure to use a socket.

I would get it going first and then work on the second.

If you get stuck and need more help, feel free to call during the day between 9 and 4 EST Monday thru Friday (859-396-3740). If you want them repaired I can get you going on both.

Ed
 
Update: received my order of ic501 chips. That did the trick to get it to fire up. Now the B+ is low (106vdc) and other side of R1 is 160vdc. No adjustment with pot. :( I'll have to pull pot and check it.
 
Check fusible resistor FR901 to see if it has gone open. Unsolder one lead of it to test. Otherwise, if tested in circuit, you get false readings.

Should read 220 ohms. If it goes open, you get low voltage and adjustment won't work.
 
Check fusible resistor FR901 to see if it has gone open. Unsolder one lead of it to test. Otherwise, if tested in circuit, you get false readings.

Should read 220 ohms. If it goes open, you get low voltage and adjustment won't work.

+2 also check R908 and X902.
 
Check fusible resistor FR901 to see if it has gone open. Unsolder one lead of it to test. Otherwise, if tested in circuit, you get false readings.



Should read 220 ohms. If it goes open, you get low voltage and adjustment won't work.



Reading 220 ohms.
 
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check R912, out of circuit.

test your B+ pot out of circuit.

look for cracks in the chassis around the flyback.


if you hit a brick wall, your welcome to send it in.
if you need parts i stock them.

Peace
Buffett
 
Update. Finally got B+ to 120vdc. Now have a sync issue I think. Using the TPG and all I get is diagonal lines. Pic shows what I get. When I turn tpg off I do see a difference as the lines start scrolling. I'll have to go over the chassis for cold solder or broken traces. Any other ideas?
6aa3a6ed406f5c6d0da58eaf8ef7086b.jpg


Update #2. Replaced X303 and have a picture now. But, the fly brightness is turned all the way down and it look like a normal picture with some distortion. Is there something else I need to test?
2aade2006fdc9e293d41d406d99e9bc9.jpg
 
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the last several times i have seen this problem on the G07 and the 4900, it was a broken trace on the neck board or around the flyback.

Peace
Buffett
 
the last several times i have seen this problem on the G07 and the 4900, it was a broken trace on the neck board or around the flyback.



Peace

Buffett



Are you talking the flyback not adjusting to black? Turned all the way down and bright picture.
 
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