Go7 13" will Not Hsync

monkey-pilot

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I recently installed a new flyback and cap-kit (from The Real Bob Roberts) for a GO7 Monitor. For about four days now, I have read just about anything and everything I have been able to locate regarding the issue I am having, and am running out of options:

It appears that all is working "OK" with the exception of the Horizontal Sync. The image will scroll, -The speed at which it travels will vary at times, and during those times that it is slow enough to notice, the characters are diagonal instead of "vertical" as I would expect.

The XO1 (H.O.T.), X301, X305 have been replaced (three times!!) with no change of results. I checked the values of R314, and R317. B+ is fine at 120V. I have not yet replaced IC501. Would it be worth changing? I am getting the feeling that I am replacing good parts with other good parts and not noticing any changes thus far.

Also, the Horizontal Frequency Pot was verified to be a 4.7K ohm range, cleaned, and replaced. It has a *very small range* that will provide an image which is not "garbled". This does not seem "normal" to me, and am wondering if I should replace the Pots on the back. When I say "small range", trust me... it sometimes seems that just breathing on the Horizontal Freq. Pot will make or break a discernible image!

Another thought that has occurred to me is the possibility that I have other components which may be missing and/or wrong values (from attempts to repair prior to me acquiring it) The schematics I have been using are very difficult to see with my poor eyesight.

One specific issue of confusion on my part is HOW should I "test" my H.O.T.??? One URL suggests that I use my DMM set to diode mode, and with the black clip connected to the HOT pin closest to the Flyback and the Red Lead on the other HOT pin, check for a voltage. I get Zero this way.. even with NEW parts!!! Another suggestion was to use the DMM the same way, but to clip the black lead to the chassis, and the Red lead touching the "case" of the HOT. This DOES produce a valid voltage range, although the monitor will still not sync Horizontally after I power up.

Please HELP!!!!! I am at my wits end here! I am reluctant to purchase (more) new parts, wait for them to arrive next week only to find there is still no change!
 
Your HOT would have nothing to do with whether the picture syncs. The HOT gives you a horizontal output, so if it was bad, you wouldn't have a picture.

First start by telling us a couple things:

1) Did you cap this with a 13" cap kit or a 19" G07 cap kit? there are differences.

2) What game is it connected to?

3) How is the sync wiring currently connected?
 
Your HOT would have nothing to do with whether the picture syncs. The HOT gives you a horizontal output, so if it was bad, you wouldn't have a picture.

First start by telling us a couple things:

1) Did you cap this with a 13" cap kit or a 19" G07 cap kit? there are differences.

2) What game is it connected to?

3) How is the sync wiring currently connected?


Encouraging to hear that the HOT is not an issue. As for the additional information:

1) I'll double check this! I have been working out of town for the past year, and it *IS* possible that I may have ordered the wrong kit! (Is there an "easy" way to distinguish the two kits based upon which parts they contain?)

2) Currently, I have the monitor connected to a Galaga Board (using an original filter Board, not a Jamma adaptor)

3) The Sync signal (composite from the Galaga) goes to BOTH the Hsync and the Vsync of the monitor..... The Negative sync inputs. I have tried to see if it made any difference to add a GND wire to the sync connector, and tie it to the ground on the other connector which has the R,G,B and GND wires..... No difference AFAICT.

Thanks for your input. I'll read up on the differences between Cap kits for 13" vs. 19" GO7's
 
Well, this is embarrassing ..... I took a look at the parts list that came with my kit.... As clear as daylight.... Across the top it reads:

"Electrohome Go7-CBO 19" Monitor"

Hmmmm..... Sounds "encouraging" in the sense that this would explain a lot, however, I hope there is not TOO many part differences!! (???)

Thanks for the prompt replies BTW!
 
Well, this is embarrassing ..... I took a look at the parts list that came with my kit.... As clear as daylight.... Across the top it reads:

"Electrohome Go7-CBO 19" Monitor"

Hmmmm..... Sounds "encouraging" in the sense that this would explain a lot, however, I hope there is not TOO many part differences!! (???)

Thanks for the prompt replies BTW!

'K... Just cross referenced my list with one that comes with the 13" kit.... Looks like 6 capacitors will change, and possibly one resistor.

...Sounds easy enough. Thanks again guys. I'll let you know how it turns out!

Cheers.
 
Oooops!

'K... Just cross referenced my list with one that comes with the 13" kit.... Looks like 6 capacitors will change, and possibly one resistor.

...Sounds easy enough. Thanks again guys. I'll let you know how it turns out!

Cheers.

I just retrieved my Monitor from the garage to work on it some more...... Guess what?.... Yep.... It IS a 19" monitor!!........ A question I have now is: Are the boards which control these monitors Physically different? I am asking because I am now wondering if what I might have could be a 19" monitor with a control board installed from a 13".... Would this be easy to determine??? Are the part designators the same, but with one board type populated differently than the other?

Sorry for my confusion.
 
Posting to subscribe to this one...I've got a CBO with a similar issue. You just breathe on the pot wrong and it flips out - not that you can get it to sync anyway. I'll post when I find a solution.
 
When you say control board, are you referring to a remote board? A G07 doesn't normally use a remote board, but I do have one that went to a 13" that was in a poker machine.

The 19" should have it's own control pots on the board, and doesn't need the remote to work. If you continue to have hold issues, start by replacing the hold pots.

If you actually have a remote board, I'd like to see a pic of it...
 
The neckboards are different pinouts.

There is also a number silkscreened down by the power cord input on the main chassis starting with an "SU11" and then inked numbers after that.

Main chassis -
SU11 03A = 13"
SU11 33A = 19"

The neckboards are marked near the CRT socket

Neckboards -
SU3016A = 13"
SU3032A = 19"

Now you could be weird like me and have a 13" chassis, a 19" neckboard and a vga CRT...but we won't go there. ;)
 
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