Kyukyoku Tiger PCB with Graphic Glitch, What to do?

[SAM]

I received a Kyukyoku Tiger PCB two days ago.

When I check every things within the parcel, the Kyukyoku Tiger PCB failed to boot.

After I fuddle with those connectors between the boards (Kyukyoku Tiger is one of those notorious double decks board), it functions normally once, but with minor graphic glitch...

Try it again yesterday, it totally not function at all. I checks the connecters again, still no use.

I had sent a few emails to the seller, but got no response so far. The board was states as fully functional when sold and was bought from a very reliable Japanese seller with good history (Most of my PCBs are bought from him and not encounter any problem till now).

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This is what I think most likely happened to the Kyukyoku Tiger PCB...

(1) It was fully functional before ship.
(The seller has a good history, and the fact that the PBC was able to boot up once.)

(2) It was damaged by the weight of the items packed above during shipment.
(Several MVS carts were packed above the PCB when I opened the parcel and the upper deck of the PCB is obviously bended due to pressure applied.)

So my guess is some solder joint of the chips on the board are loosed when the board is bended.

I know it is best if the seller is willing to exchange another board with me, but I got no response so far...

So what to do now? Is this thing easily repairable? Say heating every solder joints on the upper deck with solder iron? Should I remove all the EPROMs before heating?

[system11]

Have you tried the obvious things yet?

1) voltage
2) reseat all socketed chips

[SAM]

Have you tried the obvious things yet?

1) voltage

Just tried to adjust the input voltage, and the board works again.

So it must be 5V DC, cann't take less. Thank you.

But then there is the graphic glitch. There are dots in enemy explosion, color dots surrounding enemy heli, tanks and the stage 1 boss...

Do you have an idea of how to fix this?

2) reseat all socketed chips

You means removing all the EPROMs clean their legs and insert again?

[system11]

Have you tried the obvious things yet?

1) voltage

Just tried to adjust the input voltage, and the board works again.

So it must be 5V DC, cann't take less. Thank you.

But then there is the graphic glitch. There are dots in enemy explosion, color dots surrounding enemy heli, tanks and the stage 1 boss...

Do you have an idea of how to fix this?

2) reseat all socketed chips

You means removing all the EPROMs clean their legs and insert again?

Yes. If you're very careful, use a folded over piece of card and gently rub the legs with it, side to side. Usually this isn't required, and just the act of removing and replacing moves the dirt around enough for a connection to be made again. Under no circumstances try to file the legs unless it's a last resort on corroded or burned ones. When removing chips, use a flat blade screwdriver, just get it between chip and socket, and twist slightly - don't try to take it out all in one go, do one side then the other and so on. This will avoid bending the legs. Also, don't use the screwdriver to lever upwards, sometimes this results in the end of the blade digging into the PCB surface underneath - which isn't cool.

If this makes no difference, take a photo of the problem if you can - what you're describing sounds like several possible things.