Let's bump this up. My newer MRT104 Tablet is shelved for the moment. I can find no information on it like pinout for the connectors. The new thing is I have two JV5 units. One had a bunch of internal corrosion like a battery exploded in it. I have to tear it all the way down to check it. I also got a cleaner CPU unit. I have a smashed newer display unit with both the touch screen and the display screen damaged by corrosion jacking. I also have an older display screen unit that lacks the row of buttons at the bottom of the display, but it does have exactly the same buttons on the left. The status lights look to be a different configuration, but they may just be labeled differently. It has a USB connector on the side with a deep rubber plug to seal it. It also is slightly larger and does not fit any of the display mounts I have for the newer style units.
I recently got power cords, so I got power to the units to check them. The dirty CPU unit gives more life than the clean unit. The dirty unit has 1303 hours, and the cleaner one has 600. I plugged in the clean one to the damaged newer display and it seemed to begin start up but at some point, the magic smoke began so I removed power and will have to tear it down to check and see if I can find the offending component. I am hoping it is just a power capacitor. Only one of the status lights on the main board lights up. I tried the dirty unit, and it got farther and most of the status lights came up. The display show error on the broken display as expected but all the other status lights show good. I don't think the battery is charging much. I also took out the 9 volt in the battery tray and I know the cmos battery is toast on the dirty CPU unit. It may have blown and cause the internal corrosion. I then tried the older display unit, and it showed a white screen and nothing else. It does have the same connector for the keyboard but the clocking of the location slots are different on the older display so my keyboard for the newer unit will not fit. I have another display on the way and hope I get to see kind of display on it other than a blank broken display or the total white display.
My question is, what did you guys see on startup when the bios was smoked?
Also, I will grab some pics and post.
I really want to get this working but if I have left over parts that are not fixable then I will probably put an aftermarket touch screen in a display unit and run it to a raspberry PI or similar small computer so I can make a map display or maybe a slideshow of BFT screen caps. I could gut the display cable to run power, HDMI, and USB through it. I really hope to get at least one original unit going. I also think it would be pretty easy to replace the 5 wire touch screen in the original display unit but the actual screen seems to have a different cable than all the other NEC replacement displays I see.