I posted over on the Who forums, but thought I would try to reach a larger tech audience.

I just installed some NVRAM in my Who, and now it's not booting.

LED 19 On
LED 20 Off
LED 21 On

So blanking circuit is on.

All traces meter out including from NVRAM to the ASIC and the ASCI blanking to their respective areas, NVRAM installed correctly, no solder bridges.

I tested 5V on the NVRAM and socket and it is coming in at 4.72. The main test point on the driver board is 4.97 so a pretty significant drop. The solder joint looks fine, no cracks, etc.

If it's voltage related, what should I be looking for?
0-4 (resized).jpeg0-5 (resized).jpeg0-7 (resized).jpeg

OK, this is most definitely related to my work

I swapped the ribbon cable-no change
Installed a diff NVRAm-no change
Swapped CPU's between White Water and Who. WW worked in Who, Who would not work in WW.

I metered out U6, D1, J210 and W4 all in range.

I metered out the VCC on U8 on W1 and it was 4.64. I believe the pinout of the 6264 I read stating that pin 28 was 5V is incorrect. I believe it should be in range of the battery at 4.5 as D1 VCC side was also 4.72.

So perhaps I am running too high?

Either way, this is most definitely related to my work. Not sure if it is worth the risk to hit it with the Hakko and then reflow or just send it off to get repaired. I would hate to make it worse.

Thank you! I just went and looked over everything again and Pin 6 (A4) was looking a little suspect. I have continuity top and bottom side to game ROM, but not with the ASIC.

So that looks lie it. I am not sure if I missed this before of if this was the result of my recent reflow. My guess is I removed the through hole with the Hakko. I'll try and jumper this and see where that gets me.

Thank you!!!!!

0-8 (resized).jpeg