So i am working on this almost DOA but near mint Gorf. at first all i got was some screen raster, no sounds, would not coin up.
I check the power supply and notice the center large 2000uf 16v cap has fallen off of the board. with the power supply not connected to anything and 12v was about 20, 5v was about 13. I put in a known good power board and by 12v is now 13.X and my 5v was 5.02.
Hook up the game board set and still nothing has changed. 5v is not 4.75 under load at the board set.
I pull out a good board set and it boots up but the k4600 monitor will not sync, the best i can get is scrolling horizontal and vertical at the same time. so its scrolling on a diagonal.
I cap the monitor and reflow all solder on the small board connecting pins, 18 caps as per bob roberts site, this input board did not have a c202 and i did not have a vr201 on hand. and I am still geeing the same scrolling. but the colours look way better now.
I pull the monitor from the machine for easy adjustment (no more walking from the front of the machine to the back 1000 times) monitor is on the ground behind the cabinet hooked up and i fire it up. i get nothing on the screen.
I now hook the monitor on my test bench(us classic jamma) and adjust the vert, horiz, and that other one that you need a plastic screw driver to get to on the h/v board. now its got a perfect pic. go back to the gorf and get no game again, but the monitor is working fine.
sometimes when i boot up the game i get proper 5 and 12 volts. sometimes i get very low volts. but even when they are proper i get no game on the screen and it will not coin up. i hope i did not fry out something on the 2nd game board stack. i even turned up 5v to about 5.2 at the board set under load, with the boardset not hooked up this was about 5.45v or so
If i flip the service switch and boot it i still get the same thing.
Earlier when it would play with the sync off, I tried all of the original boards in the board stack one at a time in the good cage, one ram card worked fine, one would bring up strange sprites, and every other board would cause the game not to boot, so the only good board out of the original set was the very last ram board.
Any ideas guys
I check the power supply and notice the center large 2000uf 16v cap has fallen off of the board. with the power supply not connected to anything and 12v was about 20, 5v was about 13. I put in a known good power board and by 12v is now 13.X and my 5v was 5.02.
Hook up the game board set and still nothing has changed. 5v is not 4.75 under load at the board set.
I pull out a good board set and it boots up but the k4600 monitor will not sync, the best i can get is scrolling horizontal and vertical at the same time. so its scrolling on a diagonal.
I cap the monitor and reflow all solder on the small board connecting pins, 18 caps as per bob roberts site, this input board did not have a c202 and i did not have a vr201 on hand. and I am still geeing the same scrolling. but the colours look way better now.
I pull the monitor from the machine for easy adjustment (no more walking from the front of the machine to the back 1000 times) monitor is on the ground behind the cabinet hooked up and i fire it up. i get nothing on the screen.
I now hook the monitor on my test bench(us classic jamma) and adjust the vert, horiz, and that other one that you need a plastic screw driver to get to on the h/v board. now its got a perfect pic. go back to the gorf and get no game again, but the monitor is working fine.
sometimes when i boot up the game i get proper 5 and 12 volts. sometimes i get very low volts. but even when they are proper i get no game on the screen and it will not coin up. i hope i did not fry out something on the 2nd game board stack. i even turned up 5v to about 5.2 at the board set under load, with the boardset not hooked up this was about 5.45v or so
If i flip the service switch and boot it i still get the same thing.
Earlier when it would play with the sync off, I tried all of the original boards in the board stack one at a time in the good cage, one ram card worked fine, one would bring up strange sprites, and every other board would cause the game not to boot, so the only good board out of the original set was the very last ram board.
Any ideas guys

