warped pcbs in cart

I just got a legit Prehistoric Isle off of Ebay.

I had a lttle bit of trouble getting it to behave (no sound, lines on screen, would not boot). Contacts were cleaned twice. Eventually it ran fine.

But I noticed the boards have a very slight curve to them.

Is this fixable?

I loosened the screws about 1/4 turn, and am storing the cart flat so that the high part (middle) of the boards are up (so they might get pulled down by gravity).


Feedback please.

The cart circuit boards are small, there is little mass to cause the boards to sag. A slight warp will not have any detremental effect on the operation of the board.
With age, heat expansion/contraction there may be slight warping, this is probably a red herring- you may have a problem else where. Make sure the cart contacts are squeeky clean.
http://www.hardmvs.com/html/cleaning.htm

ok

I had heard if there is warpage, that some contacts might not make contact

I tried to post earlier but the site went down..

Yes...this is true...

The carts casing pressing on the PCBs would cause the warping.
I'm not sure if the pcbs will remain warped after removal of the case if they were being warped for an extended period of time
.....................

The old warping of the boards problem...Your actually the first person I've seen besides myself who has had this problem..(and noticed this warping)
I talk about this problem often...Usually after when people are having problems with a cart that gives still problems even after a good cleaning..
I've had this problem with at least 3 carts in all of my time collecting MVS carts..

Last cart comes to mind is/was a Neo Bomberman (boot)..When I got it just would not boot up right..no sound, and lines on screen...plus resetting or just not showing up..

First thing I did is Super clean the contacts with light sand paper,,the required me to open the cart..
After cleaning the pcbs I put them back in and closed the cart..I noticed the cart screws felt spongy when tightening and the case was pressing on the pcbs more then usual..
So I really didn't notice they were being warped..I inserted the cart and it worked better but still had problems.
I took it out again..(pissed)..then looked the pcbs while in the cart and noticed they were warped...
I loosed the screws real quick.. and fooled around loosening and tightening them up watching as the boards warped when the screws were tightened.
I didn't have a spare case at the moment so what I did is file a few spots in the inside of the case(slightly) to get cart pcb wobble.
Before I did this I did try the cart with the screws loose enough and it worked fine besides it's after demo reset problem that I think is a EPROM program issue.
The sound was on and the lines were gone etc..
The boards were straightening when the screws were loose..
Leaving the screws loose is not a good thing though..If they fall out onto the motherboard then...
I had to shave/file some plastic in the case to get it to close right...But you have to be careful what you file..
If you take off too much one pcb will move to much to one side and hit the other.

I'd say if you can..try the pcbs in another carts case..Just to see if they straighten out etc.
(I never tried that..Shoot maybe the resetting after demo with stop...)
If you take a ruler and line it up to the pcbs connector edge you can see if they are warping/warped..In and out of the case..
You'll know that the carts are sitting right if you get a slight wobble while they are in the case..


I think it was one of the KOFs that gave me this problem too.

sand paper?

There's gotta be something better to use than sand paper on the contacts.
You don't want to remove the metal!

bconner said:

There's gotta be something better to use than sand paper on the contacts.
You don't want to remove the metal!

Click to expand...

I also use "dry" green Scotch Brite...but it's more work....it's safer though..


I don't press hard when I use very fine grain sand paper.
I clean each contact individually until each one shines..It doesn't take much but it's timely..
Then I use contact cleaner to clean off all the residue/dirt..

I say though..if you can get the contacts shiny gold without using those methods then don't use either.
I really take a good amount of time to clean my carts connectors gently and I don't have to do it often..Usually only on newly acquired carts.

With Alcohol and or Contact cleaner alone I can only get the contacts clean to a yellow color but no shine.

I've never tried a pencil eraser on an MVS cart contacts.
Maybe that'll work..

eraser

Erasers pick up a lot of dirt, but leave some residue behind.
That's why I follow with 91% alcohol.
They get diry fast too, so but a bunch at the local dollar store.

bconner said:

Erasers pick up a lot of dirt, but leave some residue behind.
That's why I follow with 91% alcohol.
They get diry fast too, so but a bunch at the local dollar store.

Click to expand...

This is exactly what I do. It works great!

bconner said:

Erasers pick up a lot of dirt, but leave some residue behind.
That's why I follow with 91% alcohol.
They get diry fast too, so but a bunch at the local dollar store.

Click to expand...

Neo Ash said:

This is exactly what I do. It works great!

Click to expand...

Cool...

I have to try this method out.

repeat

sometimes I need to repeat with the alcohol and Q-tips