Mortal Kombat 2 Sound Board Repair Log

zenomorp

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Donor 2015
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Symptom: Dead. No LED, no test tone, no static, cold amp heat sink...nothing.

-) Replaced every capacitor. No change.
-) Replaced the amp. Partial success. The amp/heat sink now heats up to normal levels and I can hear some static that changes based on what's on the screen, but still no test tone and the LED is not illuminated.
-) From past experience, I know that a bad clock crystal or a bad U2 rom will cause the LED to not illuminate so I replaced the clock crystal as I thought that was the more likely of the two to be bad. Nope. Still no LED or test tone.
-) Replaced the U2 sound rom. Success! Full sound with no defects noted.

So all told, there were two issues with this board. The amp was bad and the U2 rom was bad. Posting this for posterity in case anyone wants to take note for future reference. Game on!








 
Cool...I'm building a MK2 and have a untested sound board but as soon as I find a MK2 main board I will know if it works or not and will keep your fix in mind if mine is dead..
 
I've got a couple extra main boards. Shoot me a message if you want to and we can get you fixed up.

Cool...I'm building a MK2 and have a untested sound board but as soon as I find a MK2 main board I will know if it works or not and will keep your fix in mind if mine is dead..
 
Symptom: Dead. No LED, no test tone, no static, cold amp heat sink...nothing.



-) Replaced every capacitor. No change.

-) Replaced the amp. Partial success. The amp/heat sink now heats up to normal levels and I can hear some static that changes based on what's on the screen, but still no test tone and the LED is not illuminated.

-) From past experience, I know that a bad clock crystal or a bad U2 rom will cause the LED to not illuminate so I replaced the clock crystal as I thought that was the more likely of the two to be bad. Nope. Still no LED or test tone.

-) Replaced the U2 sound rom. Success! Full sound with no defects noted.



So all told, there were two issues with this board. The amp was bad and the U2 rom was bad. Posting this for posterity in case anyone wants to take note for future reference. Game on!

















PM sent, I have some questions about your successful repair.
 
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