Gravitar tech Q`s

RetrOmatic

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I have moved my questions now to here , as it is the right forum ,

I have the game running ok ,but needs some fine tuning i have a few q`s if someone has the time please .

First up though , i will down load the manual , this has to be done .

Q1 , when playing the game , the explosions make the screen go blank [ black ] ,through the added vibration . i need to slap the CP to get it back [ not that hard of course ] . there is either a loose connection , or could it be the wells gardiner playing up ?

Q2 , i feel the picture size needs adjusting , there is xy line pots , and xy size pots , which ones to i adjust , and do i need to recheck the B + after doing it ? where are the points for checking voltage ?

Q3 , where are the voltage spots to check the pcb`s voltage , that needs to be done .

Thankyou for reading , i hope some vector wizard can help me here ,

Regards Paul .
 
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A1. Could be broken adjustment pot legs, or loose connectors to the monitor or frame mount transistors. try lightly tapping the board then the monitor to narrow down where.

A2. Adjust size pots then center pots repeat until you get the size and center you want. it shouldn't affect +B

A3. There will be test lugs on the board for voltages. most people check at chip level.
 
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A1. Could be broken adjustment pot legs, or loose connectors to the motor or frame mount transistors. try lightly tapping the board then the monitor to narrow down where.

A2. Adjust size pots then center pots repeat until you get the size and center you want. it shouldn't affect +B

A3. There will be test lugs on the board for voltages. most people check at chip level.



I take all your advice in Talon , thankyou !
Between me and my tech [ phone ] it is definately a tube yoke board issue , as now i have no game on the screen at all , the gme is playing , i have power to the yolk [ orange glow ]

The Yoke board was in a real poor state , as it has a big crack going from L to R [ pics soon ] , so some tech gut ages ago has bridged/wire soldered to fix it ,

BUT never superlued the crack back to original position , so the board has been able to flex , and stress out the component legs .

I have taken it out , removed all the bridges , now i will super glue it back flat , scratch some new copper , and re solder every leg , i bet this will fix it .

As far as size , i will follow your advice , as soon as i get this right . I will turn the color drives up to color bleed , then back them off a tad , then adjusst the bias to avoid double lines etc .

Thaks Paul .
 
I would look to buy a second hand neck board if I were you Retro

It's not great to have cracks in a neckboard as there are 1000's of volts jumping around

I have REALLY gone over this yoke board , checked continuity on all the legs on their tracks , the bbest i can get is a bunch of blue vector lines , sort of trying to resemble the attractor screen , or even the game play .

This is with the screen pot turned all off , and the focus up full . I wonder if there is anything suspect on the Pcb board behind the focus section ,
[ is that the deflection board ? }

The red and black wires coming into this board [ in a plug ] , are not looking good , i either hard wire them , and ditch the plug , or get a new plug / pins

My tech guy has yoke boards , i think it is time to pay him a visit .
 
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