exxos's Atari, Amiga & retro forum

As my board is now built, opening a new topic to keep track of things. :D

Finally got one of my boards built and powered on Saturday afternoon at our local Atari meetup but got no output to an LCD monitor via the cable created. :cry: I have made all modifications except the 16mhz one to the board.

The video cable created was a 13 pin to VGA colour video cable to resolve the video port pin issue. I used the pin outs from Dr Coolzoc's website and swapped the 13 pin connector pins out so they matched the PCB pin outs. I have attached a PDF of the cable created. I should also add that I used a 15 pin female connector and not the male one shown in the attached image and connected the cable from the monitor to this. The monitor is a known one that works at 15khz.

I have left the board with a friend who is an electrician by trade for some diagnostics. He was there when we powered on and initial diagnostics with a multi-meter showed that CPU halt was a possible cause for no video output. Any prompts on diagnosing the issue? My friend has a scope and should be able to do some fault finding on the board.

It can only really be, bad soldering, solder shorted to a via somewhere, bad contact on sockets, or bad chips. Other than metering everything out which is very daunting vs each signal on the schematic, it's the only way to find out which line are "broken", there isn't much else if its not even trying to boot.

Hi kodak80

How is your board coming along?

Have you been able to track down any solder issues. Based on Forgottenmyname and my experience this is the major problems we found in getting the board running.

Even when it’s running I still found areas that needed cleaning up.

Icky

Hi Icky

I have been away on a spring break for the last week so have not had a chance to do anything. I left the 1st board with a friend who was going to use his scope on it to do somae diagnostics. I will be catching up with him on Saturday to see how he went. :)

I have started assembling my second board though over the last day. Just missing the RAM board and the 74LS02N chip to complete this assembly. Should be able to test this new board on Saturday as well. I have only made the reset fix to this 2nd board so far and have made up a 13 pin to 15 pin VGA cable to correct the 13 pin output.

I have also purchased a 2 channel 50mhz USB Osiloscope and am awaiting its arrival so I contemplate using it with diagnosing my boards. I will need to learn how to use this as well. :coffee:

Good luck for Saturday then Kodak, you'll get to grips with the scope ok, it's just learning to interpret what the results are.

Both of my boards are now alive. :yay: :yay2: :dualthumbup:

Board 1 has the mods and is booting to TOS with stable video. Paul, my mate who is helping me with the troubleshooting has tidied up some of my soldering and re-did the modifications. Being pedantic he used SMT resistors which can be seen in the images.


Board 2 only has the Reset modification so far but is booting to show a row of bombs. Just need to add the rest of the modifications to this board.

That does look good with the smd resistors. My hands shake too much these days, so god only knows which pin mine would have ended up connected to.

Well done!

:cheer: :cheer: :cheer: :cheer: :cheer:

Great progress

2 more born today :)

Exxos is building up quite a family here

Nice soldering - I too would struggle with shakes Forgottenmyname.

:bravo: :coolpics:

My hands shake to much to finer stuff as well these days :( Its why I sent off the STE boosters to have the finer pitch header pins soldered for me.