need ideas on fixing 6 slot.

cack01 · Dec 3, 2004

My 6 slot is giving me graphical problems on all my games. Each game has its own seperate graphical problems which remain exaclty the same no matter how many games are installed, or which slot it is inserted into.

5V rail is at 5.2
I have cleaned all carts and slots. I do not feel this is a cleaning problem, since there is nothing random about any thing I see on the screen.

What else is there to check? Bios? chips? Voltages?

Cleaning wise I have done everything short of sanding the contacts. All games worked perfectly before on a 1 slot board.

ttooddddyy · Dec 3, 2004

Make sure there is a good clean contact on the plug/sockets that connect top and bottom boards. Has the battery leaked and caused corosion on the pcb tracks.
Check for bent component pins that may be shorting out on the underside of the boards.
Do any of the LS244 etc ICs on the top board run hot.
The 5.2, is that at the jamma/mvs edge connect or psu ?
Check the edge connect contacts for the 5 volts, they become toasty-carbonised and resistive.
I would also say squeeky clean is not clean enough, but it seems youve gone down that path already.
When the board is running and you tap it, is there any effect on the fault?
How does it look with the RGB test on screen.
Just a few ideas. Good luck cack01.

cack01 · Dec 3, 2004

ttooddddyy said:
Make sure there is a good clean contact on the plug/sockets that connect top and bottom boards. Has the battery leaked and caused corosion on the pcb tracks.
Check for bent component pins that may be shorting out on the underside of the boards.
Do any of the LS244 etc ICs on the top board run hot.
The 5.2, is that at the jamma/mvs edge connect or psu ?
Check the edge connect contacts for the 5 volts, they become toasty-carbonised and resistive.
I would also say squeeky clean is not clean enough, but it seems youve gone down that path already.
When the board is running and you tap it, is there any effect on the fault?
How does it look with the RGB test on screen.
Just a few ideas. Good luck cack01.

Some of those I won't be able to answer on till tomorrow, but for the answers I know now.

Battery and caps showed no signs of leaking
I checked for pins being shorted, but It was more of a glance than an actual
inspection.
5.2 was at the motherboards jamma contacts (I have only cleaned them with alcohol, so there could be some corrosion on there.)
When I "wiggle" the cart the problem areas will change, but never for the better. (This could mean I do have some bad contacts, so I have decided to do another cleaning tomorrow.)
I blew out the plug/sockets on the mother/daughter board and there was no change.
RGB and crosshatch test are flawless.

Thanks for the help.
I'll post again after I check the heat of the IC's and clean the whole thing with a good cleaner tomorrow.

galfordo · Dec 4, 2004

Definitely take tttttodddyyy's advice on checking your board for shorts between the upper and lower pcb's. There was a short when I was trying to install a new battery in mine, and it was causing 4 of 6 slots to show garbled graphics - the sound usually worked though. Anyway, I'd be sure to double check for upper/lower pcb connections that should be happening.

ttooddddyy · Dec 4, 2004

galfordo said:
Definitely take tttttodddyyy's advice on checking your board for shorts between the upper and lower pcb's. There was a short when I was trying to install a new battery in mine, and it was causing 4 of 6 slots to show garbled graphics - the sound usually worked though. Anyway, I'd be sure to double check for upper/lower pcb connections that should be happening.

did you end up getting that board set to work OK Galf ?

cack01 · Dec 4, 2004

ok my findings so far:

I found a few pins on a F251 IC that had gunk all over them. I also straightend some pins which I felt were suspect. After another cleaning I booted up and still had the same exact problems. My board seems to have a film on it I never noticed, I would like to get it off but I do not have any antistatic wipes on hand.

I looked further and found a trace has been broken and a small gouge had been made in the board. The trace comes out of one of the bigger IC's which has this on it:

LSPC-A0
89080702
9111Ek712
(It is square and there are three almost identical chips. This one is the furthest to the right if the jamma edge is facing you.)

The odd thing is that the trace goes nowhere. It comes out of the IC and then just ends about 6 inches away near nothing. Also isn't the 6 slot a 3 layer design, if so would one trace make a big difference. I know the answer is yes, but its just a thought that crossed my mind.

Any thoughts? I have never repaired a trace, but I done much harder things with a soldering iron

.

thanks

EDIT: I believe the trace goes to pin #112. Any idea on its function.

cack01 · Dec 4, 2004

6 Slot fixed!!!

I redrew the trace and 5 out of the 6 games look great. The other one I think just needs a little attention, so no worries there. Most importantly metal slug 3 is working 100%

galfordo · Dec 4, 2004

ttooddddyy said:
did you end up getting that board set to work OK Galf ?

Yeah, it's working fine now - it was the battery that was shorting out the board above it. After I removed the battery, everything worked fine again.

I was thinking about wiring the battery remotely, but if I do that I'll have to solder pretty close to the pcb and will probably melt some of the silicone. I'm still a little nervous about that.

The positive terminal is ok, as it extends a safe distance out from the board, but the negative one is a real mess. The negative pin is pretty short and it isn't even connected securely to the pcb (it rotates around). Oh, and the solder I was using last time wasn't sticking well at all - the battery kept coming loose. I'm still a little nervous about messing with it.

cack01: glad you got your 6-slot fixed! Good luck on that last slot, man.

ttooddddyy · Dec 5, 2004

alls well that ends well

NEgO MANIAC · Dec 5, 2004

I still have 6-slot problems. All the games freeze, no sound, #2 slot won't work. I tried the voltage check. It was at 5.5 and I put down at 5.2. Worked for a little while and I turned the machine off then on and it froze. I still haven't got any ideas for the sound. Soooooo unhappy :crying:

ttooddddyy · Dec 5, 2004

are any of the LS chips getting hot. Scrub that slot.
http://www.hardmvs.com/html/slotCleaning.htm

Gummy Bear · Jan 7, 2005

NEgO MANIAC said:
I still have 6-slot problems. All the games freeze, no sound, #2 slot won't work. I tried the voltage check. It was at 5.5 and I put down at 5.2. Worked for a little while and I turned the machine off then on and it froze. I still haven't got any ideas for the sound. Soooooo unhappy

Try all of the above.

If that fails, then it's time to embrace the horror my friend...
The 6F has the highest malfunction rate of any Neo.

Unless preventative measures are taken, it is highly likely that problems will develop with a 6F.

I know what causes them to die and it is completely avoidable if only SNK hadn't skimped on parts.

ttooddddyy · Jan 7, 2005

Gummy Bear said:
Try all of the above.

If that fails, then it's time to embrace the horror my friend...
The 6F has the highest malfunction rate of any Neo.

Unless preventative measures are taken, it is highly likely that problems will develop with a 6F.

I know what causes them to die and it is completely avoidable if only SNK hadn't skimped on parts.

Welcome to the forum Gummy Bear

Could you elaborate on these preventative measures.

I have two 6 slots and have no probs, you may be likely to have problems with a given slot simply because there are more, like three times more likely than with a two slot. Otherwise reliability is on a par imho.

Being a large boardset it is more prone to the boards flexing resulting in broken traces. But if handled carefully it should not be a problem.

One thing to look out for is burn ups on the 5 volt connections on the jamma/mvs edge connector, these boards do draw more current and the edge connect gets pretty hot.

Gummy Bear · Jan 8, 2005

Hi ttooddddyy.

You pretty much hit the nail on the head with that one. Flex.
For whatever reason, SNK decided to ship the 6F with inter-board spacers on only two of the slots (2 and 5).
As well as that, the entire thing only sits on six pillars.

This means that the boards flex a great deal when cartridges are insterted and removed.
No matter how careful you are, you cannot stop them from flexing and it doesn't take a genius to figure out that traces aren't very flexible.

I am currently consolizing my 6F and took it upon myself to future-proof it at the same time.

What I have done to my 6F is add inter-board spacers to all 6 slots.
I have also added pillars to every point under the bottom board.
These provide straight-through support at all points and make the boards extremely rigid, they do not flex at all (you could probably stand on them with no ill effect).

The second point that you mentioned (5v) will also cease to be a threat to my system.
Although the connectors on the end of a JAMMA harness may look nice and big, the point of contact is actually very small due to the curvature of the contacts.
When you consolize a system, the soldered wire on the edge connector actually makes much better contact than a JAMMA connector and will stop the hot spot problem.
I'm not sure how you would sort that out if you did not intend to consolize, though. :confused:

ttooddddyy · Jan 8, 2005

Good suggestion on increasing the pillar supports between the two boards and the bottom feet Gummy Bear.
With the toasted 5 volts connection on the boards edge conect, I chose to wrap solder mop (copper braid) from the component side to the other side. It works well, will put a piccy up soon.

Gummy Bear · Jan 8, 2005

Good thinking ttooddddyy.

That sounds like an interesting solution.
I look forward to seeing the pics.

ttooddddyy · Jan 8, 2005

cack01 said:
Also isn't the 6 slot a 3 layer design, if so would one trace make a big difference. I know the answer is yes, but its just a thought that crossed my mind.

Yes that board is 3 layered, but as MKL pointed out in another thread (yet to confirm on a 1F around the Z80 stage, where I suspect the center layer also has other connection) the center layer is only for ground and 5 volts.

One trace could make all the difference in the world. :eek:

Gummy Bear · Jan 8, 2005

The kicker about the spacers is:

The holes are already there!
SNK just didn't use them!

Outrageous, I tell you! :very_ang:

ttooddddyy · Jan 8, 2005

The trouble with manufacturing is that extra nuts, bolts and spacers (after the initial design stage) and after production begins blows the budget out of the water.

It should have been considered at conceptual design level I guess. :oh_no:

Gummy Bear · Jan 8, 2005

Indeed it should.

It is however, an easy fix.
The only slight snag is the 'heat sheild' that is stuck to the bottom of the top board.
It covers one of the holes.

Easy to peel off and chop though.

ttooddddyy · Jan 8, 2005

My boards dont have this heat shield, are you talking about the foam layer with foil surface

Gummy Bear · Jan 8, 2005

ttooddddyy said:
My boards dont have this heat shield, are you talking about the foam layer with foil surface

Not quite.

It is sticky back foam with a kind of hard plastic/resin surface.
Mine has 2 of them in different places.

ttooddddyy · Jan 8, 2005

I never considered them as heatshields

Gummy Bear · Jan 8, 2005

I believe that to be their purpose.

I have investigated and discovered that they are positioned at the two main 'hotspots' on the boards.

ttooddddyy · Jan 8, 2005

Thanks for the info, I never quite understood the purpose
Anything else interesting you found during your investigations ?

need ideas on fixing 6 slot.

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