G07 help needed. Vertical collapse then No picture after recap.

SmartSped

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G07 help needed. Vertical collapse then No picture after recap.

Hey guys. Hope someone can set me in the right direction on this issue. I got a cocktail unit that hasn't been used in many years. The monitor actually worked really well except for the infamous screen curl. I decided to recap the whole thing and I installed the sync mod to try and correct the curl. After I did all that, the screen went into an uncontrollable vertical roll so I reverted the mod and the screen was looking great again (except for the curl although it wasn't as bad after the cap replacement). After this, I adjusted B+ to 120. I then decided to adjust the width coil. While playing with the width coil for a few seconds, the screen vertical collapsed on me (yes, I said vertical) and I couldn't get it to correct. It was just a solid horizontal line across the width of the screen. After a few minutes, it started flickering a few times displaying a bit more of the picture and then going back to a solid line. Finally, the solid line just slowly faded out completely and now I get nothing on the screen. I did get a few photos of the flickering just before it went away completely that I will attach. Anyone have any ideas on what to check first? I'm at a loss here.
 

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the 400 section is your vertical so start there. (X401, X401, IC501, etc.). make sure FR401 is good and also that it doesn't have rotted legs. did you reflow all the header pins, higher wattage resistors and also any suspect areas?? your mod may be okay and you may not have the 390 ohm resistors that are factory installed incorrect values.
 
I will check all of the parts you mentioned. I did reflow solder on the header pins so they are good. I didn't see any cracks on any of the other components.

I also already checked the resistors. All of them were correct except two exceptions. There was a 4.7k on r317, but they added the proper 390 Ohm on the bottom of the board, making it parallel with the 4.7. I didn't change this because the paralleled values were at 360 Ohms and figured it wasn't off that much from spec but I may remove the 4.7 later on.

The second deviation was on R308. They used an 8.2 K Ohm resister instead of a 10K which is only suppose to be on a 13" chassis. Furthermore, this resistor was measuring 4.4K. I have replacement coming in the mail for this one.

Other than that, I didn't see any other issues with the sync resistors. I will check the other parts you mentioned soon. Is there a way to test the IC or should I just buy a replacement?
 
I will check all of the parts you mentioned. I did reflow solder on the header pins so they are good. I didn't see any cracks on any of the other components.

I also already checked the resistors. All of them were correct except two exceptions. There was a 4.7k on r317, but they added the proper 390 Ohm on the bottom of the board, making it parallel with the 4.7. I didn't change this because the paralleled values were at 360 Ohms and figured it wasn't off that much from spec but I may remove the 4.7 later on.

The second deviation was on R308. They used an 8.2 K Ohm resister instead of a 10K which is only suppose to be on a 13" chassis. Furthermore, this resistor was measuring 4.4K. I have replacement coming in the mail for this one.

Other than that, I didn't see any other issues with the sync resistors. I will check the other parts you mentioned soon. Is there a way to test the IC or should I just buy a replacement?


buy a replacement but make sure to buy a socket so it can easily be changed out in the future. we stock all the parts if you need on our site.
 
C402 has been the culprit on 2 separate vertical collapse/vertical bouncing issues
I've had recently.
 
I pulled and checked the x401 and x402 transistors. Those are good. Fuses are also good. I did find a problem though. My x01 H.O.T. transistor is showing 000v on the diode setting across both pins so I think it may be bad. I'm going to pull it just to make sure it's the issue though. If so, I think it will solve at least part of my problem. I feel like this might be more than one issue though.

I will check C402. In those failing cases you had, did c402 short or open or was it just out of spec? Also, the manual lists it as 2.2. I'm guessing that's in uF, correct?

EDIT: I also checked FR401. It's a little nasty but it's right on spec at 68 Ohms.

EDIT2: I have on order IC501, Vertical transistors x401 and x402, and R908. I will put them all in separately just in case one of them fixes an issue. I'd like to know what exactly it will be.
 
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I pulled and checked the x401 and x402 transistors. Those are good. Fuses are also good. I did find a problem though. My x01 H.O.T. transistor is showing 000v on the diode setting across both pins so I think it may be bad. I'm going to pull it just to make sure it's the issue though. If so, I think it will solve at least part of my problem. I feel like this might be more than one issue though.

I will check C402. In those failing cases you had, did c402 short or open or was it just out of spec? Also, the manual lists it as 2.2. I'm guessing that's in uF, correct?

EDIT: I also checked FR401. It's a little nasty but it's right on spec at 68 Ohms.

EDIT2: I have on order IC501, Vertical transistors x401 and x402, and R908. I will put them all in separately just in case one of them fixes an issue. I'd like to know what exactly it will be.

C402 tested in spec at 2.2 uf. Replacing it fixed the issue , in my case.
 
Ok guys, I replaced the HOT transistor, the flyback, and the Horizontal Width Coil. I didn't replace any of the vertical stuff yet, because I wanted to see what parts would fix which issue. I turned it on and I could hear the monitor buzz but it still did not display a picture. After about 30 seconds of it being on, I heard something fry and got some smoke and it came from the vertical output part of the board around the transistors. It appeared to come from the fuseable resistor FR401. I checked it and found that it was now only registering at around 25 Ohms instead of the 68 it was reading earlier. On top of this, the new HOT transistor I just put in is now reading a short again. I'm also now no longer getting voltage at the B+ test point. Where should I go from here?
 

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I take it you can't just check the fuses in circuit on this board? I did test them in circuit and they seemed good but I can take them out.

Yes, pull them out for testing. I'm guessing just the small one, but since you have the chassis out, may as well test both I guess.
 
Ok, I tested fuse 901 and it is definitely bad.

Also, earlier, I said I thought my HOT transistor was bad from touching between the two pins on diode mode, which I read from a tutorial on a website, and the reading gave me a .025v. However reading some of the comments on this site, the actual correct way to test it is by placing the black lead on the case and the red lead on one or the the other pin? If this is the correct method, it's actually reading .500v which indicates that both my old and my new HOTs are good.

However, using this same method of testing on my voltage regulator, I'm getting .130v on one leg and .500v on another. Is .130v bad enough to warrant a replacement?

I guess the ultimate question is if the Voltage Regulator readings are bad enough to blow the fuse and if not, what else could be blowing the fuse?
 
Ok, I tested fuse 901 and it is definitely bad.

Also, earlier, I said I thought my HOT transistor was bad from touching between the two pins on diode mode, which I read from a tutorial on a website, and the reading gave me a .025v. However reading some of the comments on this site, the actual correct way to test it is by placing the black lead on the case and the red lead on one or the the other pin? If this is the correct method, it's actually reading .500v which indicates that both my old and my new HOTs are good.

However, using this same method of testing on my voltage regulator, I'm getting .130v on one leg and .500v on another. Is .130v bad enough to warrant a replacement?

I guess the ultimate question is if the Voltage Regulator readings are bad enough to blow the fuse and if not, what else could be blowing the fuse?

Bad flyback
Short or wires crossed somewhere
HOT legs touching the metal frame
 
Ok guys, I received several parts today and replaced them all but I'm still having issues.

Here's a list of parts I replaced today

F901 Fuse
X401 and X402
IC501 and tantalum cap next to it
Voltage Regulator
R908 resistor
FR401 fusible resistor

And the parts I already replaced a couple of weeks ago:
caps
flyback
HOT
Horizontal Width Coil

The good news is I can hear the monitor firing up now and I have good B+ voltage. However, I have a blank screen. When I say blank, it doesn't even look lit up like it's off. I can see that it has glow towards the neck board.

Any ideas where to go from here? I rechecked all of my work before I turned it on (which is fairly clean anyway) and didn't find any shorts. Also ensured that both the HOT and Voltage regulator are not shorted to the frame.
 
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I didn't go back and read, but did you make sure you turned up the brightness knob on the flyback?

Did you try another flyback yet?
 
I didn't go back and read, but did you make sure you turned up the brightness knob on the flyback?

Did you try another flyback yet?

I did try increasing the brightness. No change. I'd hate to buy a second flyback without knowing for sure that's the problem. Is there a chance the flyback could be bad even if the heater glows on the neck?
 
I did try increasing the brightness. No change. I'd hate to buy a second flyback without knowing for sure that's the problem. Is there a chance the flyback could be bad even if the heater glows on the neck?

Yep

Did you test for continuity coming from all of the pins of the flyback outward?
 
Before turning it on today, I checked all the pins going into the pcb. They all had continuity where needed. I used the schematic of the coils printed on the board as my guide.

My friend is going to let me borrow his tube tester tomorrow to make sure my tube didn't go out. I'll update the post on my findings.
 
If you have your meter out and had continuity coming from the 8 flyback pins all throughout the chassis, changing the flyback is your next move. (in my opinion).

the tube being the issue is very unlikely.
 
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I guess I could put my old one back in just to see if it comes back on.
 
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