Help Lab Board disconnected

[lovepokies33]

What do you mean both? We were only testing the MK5 board in the first machine.. so when you say 'not working' did the board show boot up text? You might need to adjust the CRT screens vertical adjustment stretch, as the text would be off a bit because the MK6 uses a higher res.

[spinking1982]

Ok i swapped the boards it came up for a lil bit but then the machine turned off now i stuck the mk5 board back in it's machine and i have a rolling screen and no sound, and the other machine just keeps looping rebooting

[lovepokies33]

It's hard for me to tell how technical you are, so I am conflicting going between telling you every step or just what we are trying to achieve..

Ok, so when you put the MK5 board into the MK6 machine that we were originally talking about, what did it do exactly?

[spinking1982]

Got the rolling screen off the queen but still no sound,
something interesting with the mk6 i had the cage open and that was the only error, when i shut the cage all the other errors came up and the i tried to just slightly wiggle the board and about another 5 error came up

[lovepokies33]

Hmm ok, so with the MK5 board with queen of the nile, you put that in the the MK6 machine, it booted but the screen was rolling? that can happen if you don't adjust the CRT down the bottom, or you might be unlucky and that screen might need other adjustments to handle the MK5 video, but don't worry about that for now as this was only as a test..

So was it THIS board (the MK5) that you wriggled and all of a sudden more errors came up? were they the P1 SEF errors or others? (I expected other errors to show anyway).

[spinking1982]

nah i stuck the mk6 board back in and when I had the cage door down that was the only error when i put the cage door up all the other error came back, so the i wiggled it and heaps of other errors came up.

[spinking1982]

The mk5 board I stuck back in it original machine but now I have no sound on that one....strange

[lovepokies33]

I'll help you via PM now otherwise this thread will be too long and not really interesting for others, it looks like your MK6 machine has a dry joint or bad connection on the backplane, when you changed the eproms you 'upset' things, remember these old machines have been on for years and who knows the history or treatment etc. Its very common when people think they are doing the right thing and 'clean' arcade machines, often the dust held things together lol.

[Gaming1]

Lovepokies33 just to let you know there is another loom you can put on the speakers when you do a upgrade so as it does not blow the amp ic  on the processor.

[lovepokies33]

Hey Gaming1, yup that's right all that loom does it put the speakers in series to reduce the load on the amp.

Did you ever come accross a bad backplane? I only came accross bad boards that when you bend them they 'work' or with heat etc they fail...

[Gaming1]

Yes not very often usually some one has forced the board and damaged it but on the the odd time have changed one after upgrade.dont bother repairing just throw away have heaps

[Gaming1]

The bend part is usually dry joint on CPU sometimes bad track

[lovepokies33]

Yeah, I have seen boards with little mods, usually a random little wire from the CPU behind the board and back. But I have the theory that once there is cracks in these multi layered boards they are forever haunted. As you say, just get another board.

[jasongd]

Hi Guys,
Looking at the MK6 board,, Is it an XP board???. Low res pic so not 100%, if it is a standard motherboard, you may want to install the small wafer comms board on the left side of the motherboard.
Cheers.
Jas.

[Gaming1]

Can I ask why that's only if you want printer for those programmes or am I missing something

[jasongd]

True True, Just trying to eliminate possible errors.

[lovepokies33]

The 72 pin simm has nothing to do with this.

The board is clearly an original MK6, even with the blurry photo you can see the difference in design and the give away port right next to the eproms.

Anyway, as it stands the MK6 board is screwed or the back plane has problems (very rare). When he closes the cage, the very movement of this and weight from that heavy door causes errors to suddenly appear. If you apply a small amount of pressure on the board the video starts to fail and screen rolls, and it reboots. It struggles to boot when hot but ok when cold. All these are classic signs of a board that is stuffed. Its possible for a bad dry joint on the backplane..but I doubt this.

The only way to quickly solve this, is with a spare working main board. Obviously if it too fails then its a matter of looking into it further, but there is not much more, the whole system IS the main boards. SO the only thing it can be is a backplane with dry joints (did I mention rare?) or a screwy PSU, but putting a small bit of pressure on the main board with a finger or closing the logic cage clearly rules this out.

[Gaming1]

Sounds like you have a mother board problem. Can you put the original mk 5 processor back in its machine or was it just a spare