G07-FB0 Flyback question

Radford119

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Looking to replace a 13" G07-FB0 flyback and was wondering if someone had first hand experience in putting in a flyback from a 19" G07-CB0? I have seen a lot of opinions on whether or not it will work. If it will work are there any modifications that will need to be done?

Thanks
 
Some people have said they used the 19" flyback and it worked. However, I tried it and it didn't work. Put the 13" flyback back on and it worked again...
 
Not me - yet. :)

The 13" flybacks seem to be - so far - more robust than the ones for the 19". Then again, there are far fewer 13" monitors compared to their 19" cousins. You'll hear about their failures more often because there are more of them.
 
Dead Thread Resurrection - 2 rebuilt G07-FB0's

I just rebuilt 2 electrohome G07-FB0 monitors (Caps and curl mod).
The new 19" flybacks worked, but....

On Chassis 1 - I was getting static discharge on the FB ferrite frame and the picture was shrunken just a bit. Maybe 1"
- I pulled the new flyback and put the old one back in and it enlarged the pic and I had no arcing. The pic still did not fill the screen. I am thinking the arcing was a flaw from manufacturing - it seems like a small piece of wire was protruding from the silicone on the bottom of the FB.

On chassis 2 - Small picture again and I was getting what sounded like static on the neckboard. Faint, but enough to draw my attention.
- I swapped out the FB for the old one. The picture enlarged once again and the static was reduced. The pic was still about 1.5" from filling the screen.

Some people have said they used the 19" flyback and it worked. However, I tried it and it didn't work. Put the 13" flyback back on and it worked again...

I am unable to adjust the picture to get it to fill the screen. But they are sharp, with no curling once adjusted.

I know Bob sells the width caps, but would this address my issue of getting the picture to fill the screen?

It would also be nice to know if there is a compatibility issue with the 19" FB being used in the 13". The new ones worked, but seemed to have issues.
 
I have used the 19" flyback before several times on the fbo. I don't remember any issues. The width cap kit from bob roberts is a really good way to get your picture to fill the screen.

There can be some 'trial and error' to find the perfect value for your needs, but it is a good solution.
 
Actually, I picked up this tip from Tron Guy, for the "curl" mod, place a 22uf 50v instead of the 10uf 50v Bob includes with his kit. I know I did this on a FBO chassis, and I believe it helped with the screen filling problem. Cured the curl problem for sure.
http://forums.arcade-museum.com/showthread.php?t=312442


Did you happen to use a CBO cap kit, on these FBO chassis? That 1.5" gap, sounds similar to a scenario Bob Roberts described to me, when I asked long ago about the compatibility of the 2 different kits. Have you checked the other usual suspects, HOT, VR, R908, ect? Mixing new with old, will give you some wanky stuff to chase down. Just a thought.
 
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Good tips

I will try the 22uf Cap next go around and see what happens.

I placed a bulk order from mouser for the caps, so I didnt use specific kit. I did use what the FB0 called for vs. the CB0.

I will dig into the other items when I get a bit more time. I do know the new flyback shrunk the screen more than the old. But you are likely right - the mixing of new / old might be my issue. I will have to see if i can find the VR and do a 100% change out to see what happens.

place a 22uf 50v instead of the 10uf 50v Bob includes with his kit.
Did you happen to use a CBO cap kit, on these FBO chassis?
Have you checked the other usual suspects, HOT, VR, R908, ect? Mixing new with old, will give you some wanky stuff to chase down. Just a thought.
 
I just recently rebuilt an FBO with a GO7 fly and width coil from BR and they work fine.

You need an FBO cap kit, the general GO7 is not 100% correct. You need a different VR and HOT as well if you choose to replace those. They're not the same as the CBO.
 
Update and where to go next?

Does anyone have any pointers on how to widen the screen.
I am still missing about 1" on each side.

On chassis 2 - Small picture again and I was getting what sounded like static on the neckboard. Faint, but enough to draw my attention.
- I swapped out the FB for the old one. The picture enlarged once again and the static was reduced. The pic was still about 1.5" from filling the screen.

I am still on Chassis # 2
- Double checked caps - all values were good
- Tried 220uf @ 25v in C517 and C518 (No dice)
- Neckboard popping went away (Might have been moisture)
- Tried a new FB - This one gives me static discharge like chassis #1 (I wasn't touching it, but I am sure it would give me a jolt if I did) I will try a different manufacturer, or go back to the original.
- New Pots
- R303, 306, 314 and 317 replaced.
- New FR401
- New HOT for giggles
- I have reflowed the majority of the chassis
- B+ (Non adjustable) is at 118.5

- I have not replaced the width coil (It looks good)
- I have not changed the VR
- I have not changed X4O1 and X402

I think I will order a Deluxe kit and width caps from Bob and see what happens.
 
Someone else can correct me if I am wrong, I think the smaller pic, is due to the B+ being under 120DC. I know this can't be adjusted on FBO chassis, so that leads me to believe something previous to that, is causing the issue. Shotgunning it, I would look at the VR, R908 being in range(47k Ω 1/2 watt resistor), and ensure to reflow anything previous in circuit before the B+ test point. Bob's rebuild kit will not include the R908 resistor, I mention that, in case you need to replace it.

I know having a similar problem of filling the screen with a CBO chassis, you turn up the B+ a hair more than 120DC, and you can resolve the issue.
 
Someone else can correct me if I am wrong, I think the smaller pic, is due to the B+ being under 120DC. I know this can't be adjusted on FBO chassis, so that leads me to believe something previous to that, is causing the issue. Shotgunning it, I would look at the VR, R908 being in range(47k Ω 1/2 watt resistor), and ensure to reflow anything previous in circuit before the B+ test point. Bob's rebuild kit will not include the R908 resistor, I mention that, in case you need to replace it.

I know having a similar problem of filling the screen with a CBO chassis, you turn up the B+ a hair more than 120DC, and you can resolve the issue.

Voltage regulators on these and the K7000 can vary in overall output as much as 4 volts in either direction so a 118 volt reading isn't out of the norm. It's no secret that the replacement flybacks can cause some horizontal width issues but it can also vary depending on what machine your FBO chassis is in. I've had many of these with new flybacks that were unaffected by the flyback change and others have decreased in size by as much as 1 1/2 inches on either end. In both cases, all parts related to the voltage section of the chassis were either well within spec or dead on matches to each other so to some degree, it's unexplainable.

About the only thing you can do is alter the factory width cap which is currently a .53uf and change it to a smaller number like a .33 or even smaller yet until you obtain a larger image. The smaller the number, the larger the picture and vice versa.
 
Update

Here is what I have done tonight:
Replaced IC501 and X401 / X402 and FR 401
Reflowed lots for giggles
I toyed with the Width cap values. Used a .53 & .53 to give me about .26 to see what it would do - No change...

The FB0 Doesnt have R908 ;(
I would look at the VR, R908 being in range(47k Ω 1/2 watt resistor),

I would like to crack the code on the static from the FB. If I use my discharge tool and tap the ferrite - you can see a small spark. Not normal I would say.

I think am getting feedback / bleed in the system. I probed some common areas for voltage to see what I would get and the heatsinks are giving off a voltage reading of 40ish on one and 70ish on the other.

Is it normal for the Heatsinks to be charged?

I am using an old 60 in 1 for test. I do have a pattern generator somewhere.
I did try a different JAMMA board with very little change.

I would like to solve this :)
 
Yep, brain fart, forgot the FBO doesn't have the R908.

It would make sense about the heatsinks, as energy(DC) can't be destroyed, but it can be dispersed as heat, when trying to lower/step down the voltage. A very wise man taught me that :)

Shits & giggles, do you have another width coil to toss in there? Maybe it's damaged but can't be seen.
 
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as chris25810 mentions above you will have to change the factory width cap, if you search this forum you can find multiple posts concerning this problem when using the G07 CBO flyback in an FBO, i think i robbed a replacement width cap from an old 4900 chassis i had lying around, it may take a bit of trial an error but it can be easily corrected to fill the entire screen with out replacing everything else on the pcb

good luck
 
Update

I did try to adjust the width by adding a cap. I ordered a few sets, so will try with fresh caps and see what happens.

Swapped VR STR383 and T501
Dropped in a new Width Coil. It adjusts better, but simply cannot give the width needed.

Shotgun shells are running low...
Is there a way to probe for electrical discharge that a newby can handle?
Is it possible a connection from top to bottom of the PCB was severed under the FB? Those holes are tight.


The 19" FB's are not the same as the 13"
I am going to drop the 13" back in and see what it does with the parts it has before I mess with the width.
 
Very possible. When I replace a flyback on electrohome boards I always check for cracks around the flyback. These boards are brittle from the heat of 25+ years.
 
I let it cook for a bit and...

Something died.

I took a pic and will post it later.

She started making a lot of noise ivo of the yoke / crt connector. somewhat like when you max out the screen control on the FB.

The video was severely distorted and fuzzy. It somewhat reminded me of the old round picture tubes from the way the video looked (Circular).
I have read and seen a similar pic, but dont remember where i saw it.

Has anyone seen this or something like it?
 
Pic of the Issue

I have seen this before but do not recall where...

edit
 

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