I have a D&D pin (6803 MPU) that keeps freezing and displays "Check Field Fuse or FU-1". Both fuses check out fine. I have removed both fuses and performed a continuity check on them. This occurs most often when one or two balls are held in the left and/or right teleport. The game will often reset if I lift the playfield and remove and reinsert the fuses. I have seen older posts about this issue and have tried the various recommendations without success. I have tested the ball trough Opto boards, and even replaced them with brand new boards. I covered openings into the ball trough to prevent light leakage. I reflowed the pins on the power board which remedied an intermittent power loss problem, but it did not fix the fuse error. Checked all voltages on the power board and MPU board and they were all within range according to the manual. I subsequently replaced the power board with a brand new power board. I checked the fuse holders and they appear to be sound and the solder connections do not appear to be cracked or cold soldered. Checked the pin solders on the MPU and they appear to be ok. When I run a switch test with the key pad, I get the message that outhole switch left, middle and right are closed and the switch test stops at that point. This message occurs when all balls are in the trough. Should these switches be normally closed when there are balls in the trough? Is there anything else I should try? Any suggestions will be greatly appreciated! It's a fun fast game when it works!