G07 Slow Roll

[jetusenet]

Hi;
I was searching the forums for a solution to my Robotron G07 with a rebuilt chassis and a "slow roll", just can't get it to sync.

Tried just +horizontal, tried +horizontal +vertical, tried -horizontal and also -horizontal -vertical, always rolls.

I read several posts by Ken and and the crew and finally took his advice and checked with a known good monitor and BAM, slow roll!

I checked the sync voltages, (again - thanks for the suggestion) and got 0.27vdc, well below the recommended 2-4vdc.

So at this point I can assume that I have an issue with the board-set or am I missing something?

I tried all the other recommended adjustments as well - NG.

Thanks
Jeff

 

[jetusenet]

I thought that before I go troubleshooting the boardset, let me try the known good monitor on my Sinistar, (I am working on a Robotron) and I got the roll. So I tested the sync signal on the working Sinistar and got the same .27vdc, same as the Robotron output.

My testing monitor is a newer one with composite sync so that must be the reason the image rolls, the output of the Sinistar and Robotron are H/V sync.

Anyway now it's back to the chassis, I guess the only thing left is the HA11244...

Jeff

 

[komodo]

Have you tried just +H on the monitor? I'm pretty sure Williams games are positive sync. Since you are using a newer monitor, it might be looking for composite sync and some people tie the 2 sync lines together to "combine" them to get composite sync. You are hooking up the sync wires in the same row as the RGB signals correct? This is a G07 correct?

 

[komodo]

Have you looked at this?

http://therealbobroberts.net/sync.html

 

[jetusenet]

Hi,
My Sinistar video connection is all 6 pins in a row, red, green, blue, gnd, +vert, +horiz and that's the way I hooked up my Robotron but it does the slow roll.

So just to prove it out, I then tried just +horiz NG
Then tried -horiz / -vert. NG
Then tried -horiz. NG

I Think I tried all available possibilities and each and every time, I cannot lock the vertical hold in.

BTW, thanks for the Bob R. Link. I read throught it just to make sure I was not missing anything. He even said the the Williams games uses the +horiz/+vert so it should have worked.

What I sould do next is pull the Sinistar monitor and try THAT hooked up to the Robotron.......

Thanks again for your help.

Jeff

 

[komodo]

Oh yeah. G07 has some versions with the wrong values of resistors in them and I do believe it is for the + sync.

I tried to link to a thread by Ken Layton but I can't remember how to link to threads. Here is what Ken said:

"Remember that resistors R314 and R317 (in the sync circuit) need to be checked for the correct value. The factory mistakenly put in the wrong value resistors in these locations on some chassis. Both should be 390 ohms, but the factory put in 4.7 k resistors by mistake."

You might want to check those if you haven't yet. I've seen about 3 of these chassis come across my path in the last 5-6 years. Seems to me they have yellow on the bands if they are wrong. Little fuzzy here as I haven't seen one in a while. Normally this isn't an issue as most games use negative sync.

 

[Slackmoe]

Ive come across 2 so far.

Andrew

 

[jetusenet]

Thanks again for the suggestions....

I checked and both resistors are indeed ~390 ohms.

I confirmed B+ 120v.

I checked the HV and got a reading of 26kV !! So that seems to be a problem :-(

Jeff

 

[jetusenet]

Just to confirm, where is the recommended location of reading the B+?
I want to be sure I am not reading it incorrectly.

Thanks
Jeff

 

[jetusenet]

I don't have a schematic of the g07, (I'll do some searching) but was wondering, does the HA11244 have any control of the HV?
Thanks
Jeff

 

[jetusenet]

Hi;
Went back just to be sure and I have 120v solid at B+ (taken at the large cement resistor - white wire) but my HV is still 25kV+.
Any suggestions as to why the HV would be so high even when the B+ is correct?
Bad HVT?
Thanks
Jeff

 

[paul400]

I don't have a schematic of the g07, (I'll do some searching) but was wondering, does the HA11244 have any control of the HV?
Thanks
Jeff

if HA11244 isnt working you wont get any HV.i dont think the HV is the problem, if the chip isnt working right it could give you a slow roll, maken sure you reflow those header pins.

 

[jetusenet]

if HA11244 isnt working you wont get any HV.i dont think the HV is the problem, if the chip isnt working right it could give you a slow roll, maken sure you reflow those header pins.

Hi;
The G07-904 manual stated that at zero beam, I should have between 22.5kV and 25.5kV so I guess I am within acceptable parameters.
I ordered a replacement HA and should be receiving it soon so we shall see how it goes.
Thanks for the back-up.
Jeff

 

[Jedidentist]

Not that this adds much to anything, but I'm having the exact same issue with a G07 in my ROTJ. It never had this problem until a few days ago. At least this gives me other things to look into.

 

[jetusenet]

Hopefully I'll have the solution soon...........

 

[Jedidentist]

Here's what I'm getting right now:

 

[jetusenet]

Exactly the same issue.....

 

[Jedidentist]

Well, after a little more thought, etc. I think I'm just having a Big Blue issue. I reflowed the solder on everything, and I don't think I have a synch issue because I never had this issue before...even though the game has never really been that stable. After looking on BR's site I read these statements regarding failure of the Big Blue:

Here are 5 Big Blue Symptoms that are eroneously blamed on the monitor.

1 Intermittent lightning streaks in pic/hum bars/weaving.
2 Blank raster... steady or intermittent.
3 Jumpy pic sometimes described as jiggles.
4 Failure of H hold to lock in.
5 Intermittent vertical roll or failure to lock in.

Note: The symptoms above are only the ones that mimic a monitor failure problem, but a bad Big Blue will manifest many other symptoms from the game being totally dead to the start LEDs flashing to a loud audible hum & more. Make sure you have a known good BB in place before you go tearing down a game hunting a problem that it is responsible for.

This would likely account for my rolling screen as well as the "clipping" noise I'm getting as the Big Blue might be leaking AC. Of course, now I've got to wait until wednesday to get my rebuild kit from BR to find out.

 

[jetusenet]

Mine is a Williams game, no BB..........

 

[jetusenet]

UPDATE:

I replaced the HA11244 and there is no improvement whatsoever - exactly the same problem.. a slow roll that when adjusted, will not "snap" locked....

I will get the DMM out and look for other issues that I might have missed...

UGG!