Game King Help

[Tilt]

Ok, let's try this and see what happens.  Remove the MPU and on the backplane (motherboard) is a small 8 pin EEPROM in a socket.  Use a small screwdriver to pry it out.  Be careful removing it so you don't bent the pins up just like the larger game EPROMs.  Then put the keychip in the base socket, re-install the MPU, power it up, and see if you get a menu or not with it out.

[sixcardmark]

 

[dsndblm]

OK, I can remove the EEPROM. Do I power up with GME chips, PXL SIMMs, and CFG SIMM removed also or do you want me to reinstall them first?

[Tilt]

It doesn't matter.  If you already have them re-installed leave them in, if not do it without them.

[dsndblm]

No chips, no EEPROM = No Signal Error message
Board populated with Key 022 = No Signal Error message

Base chip installed machine boots to screen with coin hopper error. Now, it gets better. The touch screen doesn't respond.
Is there someone that has a spare board for this machine or can refurbish the old board?

[Tilt]

Did you remove the EEPROM from the backplane or one on the MPU?  The one on the backplane is the one I was talking about.  I attached a picture, it's the only socketed component (U2) on the board.  The pic shows two bakplane boards, that was just to show U2's orientation can be different, so pay attention to where pin 1 is.  It should have done one of two things, either the keychip menu appears, or it shows you that keychip error message again.  The No signal message leads me to think that maybe you pulled an 8 pin chip off the MPU, that's the video FPGA configuration PROM.  Without it you will get a no signal error because the MPU can't produce a video signal without it.

Yeah, member Lookes repairs 3902 boards.  Not sure you need that yet though.  When did the touchscreen become non-responsive?

[dsndblm]

I attached a couple of pictures as I'm at a bit of a loss. I don't see a socketed U2 on my MPU or backplane. U27 doesn't look like a socketed component. It looks to be soldered directly to the board.

You're correct, I did remove the 8 pin device, U17 from the MPU, sorry about that.

The touchscreen is working now. I went back and made sure everything was seated correctly. This game has seen some humidity at some point. I've found some oxidation on some of the pins and sockets.  I used a very small amount of DeOxit and a q tip to clean all the items I've had apart.

[Tilt]

Ok.  Yeah, without U17 you'll get no video as you found out.  The backplane is mounted on the back of the machine.  It's what your MPU board plugs into when you slide it into the machine.  If you take a flashlight and shine it where you slide the MPU tray in you'll see back there with a bunch of wires on the connectors at the bottom of it.  U2 is a socket above the long connector that mates with the MPU board.  That's the component I'd like you to remove and then put the MPU board in with Key 22 installed and see if you get the Keychip menu or the Keychip error message.

Glad the touchscreen is working again now.  DeOxit is some good stuff in my book.

[dsndblm]

Something different on the screen!

Clear ram before reboot    No
Clear E2 and ram before reboot  No
Perform keychip after reboot     No
   Reboot machine

Can't thank you enough for all the help.

[Tilt]

Hurray!  That's the keychip menu you should be seeing all the time   

What I believe has happened is either your machine was intentionally setup up at some point to require additional security or the EEPROM became corrupt to make it appear that way.  I believe that during the keychip boot process it reads certain data from the EEPROM and if it matches a value that requires these additional security measure then it pops up with an error message that you were seeing.  When the EEPROM was removed the Keychip didn't see the high security data anymore so it booted the keychip menu that we expect to see. I can't say with certainty that's what happening because I don't understand what all the code in the keychip does specifically.

So, the next question on your mind...how do we fix it?  Easy, we'll replace the EEPROM with a blank one and you should be good to go after that.  You can't plug it back in after the menu appears and use it to erase it from the menu because you can't get to it with the MPU in place and it's bad idea to plug electronic components in when the power is on anyhow.  If you have an EPROM programmer you could erase it yourself, but I'm betting being fairly new to the hobby that you don't.  I have a bunch of them, if you PM me your address I'll send you one at the price everyone loves...free.  That should do it.

[Tilt]

[dsndblm]

Hurray!  That's the keychip menu you should be seeing all the time   

What I believe has happened is either your machine was intentionally setup up at some point to require additional security or the EEPROM became corrupt to make it appear that way.  I believe that during the keychip boot process it reads certain data from the EEPROM and if it matches a value that requires these additional security measure then it pops up with an error message that you were seeing.  When the EEPROM was removed the Keychip didn't see the high security data anymore so it booted the keychip menu that we expect to see. I can't say with certainty that's what happening because I don't understand what all the code in the keychip does specifically.

So, the next question on your mind...how do we fix it?  Easy, we'll replace the EEPROM with a blank one and you should be good to go after that.  You can't plug it back in after the menu appears and use it to erase it from the menu because you can't get to it with the MPU in place and it's bad idea to plug electronic components in when the power is on anyhow.  If you have an EPROM programmer you could erase it yourself, but I'm betting being fairly new to the hobby that you don't.  I have a bunch of them, if you PM me your address I'll send you one at the price everyone loves...free.  That should do it.

Tilt,

Thanks so much for all your help. It's very generous of you to spend all this time helping me out!
These games are a lot of fun to work on. The guy that owns it is going to be very happy to get it back.

When I get the blank EEPROM, do I follow these instructions to complete the setup? 
https://newlifegames.com/nlg/index.php?topic=883.0

Again, thanks for the help. Without it, the game probably would have ended up in the dump, or made into a cat bed. 

[Tilt]

Glad to help.  Yes, follow those steps and you should be all set when you get done.  If you want to make a simple change after the initial setup then clear the credits on the machine, install the keychip, power on and when the menu appears only change the perform keychip operation after reboot to yes.  Don't erase the RAM or EEPROM or you will have to set everything back up again.  The PSR I attached a few posts back for your game can be helpful too.  You'll get comfortable doing it after a couple of times.