Fixed: Another AES

[channelmaniac]

Had an AES in for repair that appeared to be dead but would play blind.

Repaired bad trace on pin 126 of the NEO-B1 IC to fix the video clock and bring back the video.

Fixed a bad trace on pin 125 of the NEO-B1 IC to fix a graphics corruption problem.

Board played for about 10 minutes then rebooted to a red screen - bad Work RAM. Replaced the surface mount 62256 SRAM at R6 to bring it back from the dead. Finish the repair by running the game for a half hour to burn it in.

Enjoy!

 

[Neo Geo MVS]

Had an AES in for repair that appeared to be dead but would play blind.

Repaired bad trace on pin 126 of the NEO-B1 IC to fix the video clock and bring back the video.

Fixed a bad trace on pin 125 of the NEO-B1 IC to fix a graphics corruption problem.

Board played for about 10 minutes then rebooted to a red screen - bad Work RAM. Replaced the surface mount 62256 SRAM at R6 to bring it back from the dead. Finish the repair by running the game for a half hour to burn it in.

Enjoy!

Nice job RJ is there anything you can't fix, lol.

 

[channelmaniac]

Nice job RJ is there anything you can't fix, lol.

Yes sir, Plenty!

I do like documenting things in the hopes that it helps others keep their systems running.

RJ

 

[zapatistab]

Can I have it?

 

[Kunio]

Channelmaniac for president! That's for damn sure!

 

[ckchan]

Any idea to fix the system which keep on resting when switch on?

 

[channelmaniac]

Thanks everyone!

I'm hoping that one day one of the mods will need a system fixed and I can bargain with them to get a custom title of Mr Neo Fix-it.

Any idea to fix the system which keep on resting when switch on?

Yes.

If the box is "stuck in watchdog", in other words, constantly resetting itself then you have to look at what it takes to boot: The CPU needs to read the BIOS ROM and initialize the Work RAM.

If it cannot do that then the watchdog timer expires and clobbers the CPU over the head via the reset line to try and restart it. If it cannot successfully restart the CPU then it hits it again... and again... and you have a stuck in watchdog problem.

Check for bad traces on the address, data, and control lines between the CPU, work RAM, and the BIOS ROM.

If they are all good then replace the surface mount work RAM.

RJ

 

[ckchan]

Thanks for the tips!
I will try to check the thing you mentioned.

ckchan

Thanks everyone!

I'm hoping that one day one of the mods will need a system fixed and I can bargain with them to get a custom title of Mr Neo Fix-it.



Yes.

If the box is "stuck in watchdog", in other words, constantly resetting itself then you have to look at what it takes to boot: The CPU needs to read the BIOS ROM and initialize the Work RAM.

If it cannot do that then the watchdog timer expires and clobbers the CPU over the head via the reset line to try and restart it. If it cannot successfully restart the CPU then it hits it again... and again... and you have a stuck in watchdog problem.

Check for bad traces on the address, data, and control lines between the CPU, work RAM, and the BIOS ROM.

If they are all good then replace the surface mount work RAM.

RJ

 

[JMKurtz]

I'd give you the custom title but I don't think I have that capability. I think you've become a great asset to the Neo community!

I'll suggest it to one of the other admins though.

Jeff

Thanks everyone!

I'm hoping that one day one of the mods will need a system fixed and I can bargain with them to get a custom title of Mr Neo Fix-it.



Yes.

If the box is "stuck in watchdog", in other words, constantly resetting itself then you have to look at what it takes to boot: The CPU needs to read the BIOS ROM and initialize the Work RAM.

If it cannot do that then the watchdog timer expires and clobbers the CPU over the head via the reset line to try and restart it. If it cannot successfully restart the CPU then it hits it again... and again... and you have a stuck in watchdog problem.

Check for bad traces on the address, data, and control lines between the CPU, work RAM, and the BIOS ROM.

If they are all good then replace the surface mount work RAM.

RJ

 

[channelmaniac]

Thanks Jeff!

I really appreciate you taking the time to do that.