My EBC started acting funny a few days ago. It would stop scoring and talking and various other odd things. It eventually blew the fuse on the playfield and shut down the solenoids and a bunch of other stuff. I re-flowed the connectors on the power board before replacing the playfield fuse (1A SB), as I had some problems early on with this machine and I wasn't very good at soldering the first time I went through the board. After replacing the fuse, I rebooted several times, ran the solenoid test for 10 minutes and then played for about 30 minutes before the gremlins came back.

Now, displays are dead and the game does not boot. Squawk and talk is powering up and tests with the button on the sound board. I can't get to the "test mode" to look for bad solenoids, stuck switches, lights, etc because it won't finish booting up.

The 6803 board would give me 6 flashes and if I gave the wires in the J3 wiring harness a jiggle, the control board would give me two more flashes and the displays would light up, but no pinball allowed. I got a couple of "Tilt" warnings early on and it would still occasionally talk and I could still operate flippers. Now, none of the flashy lights or solenoids work.

According to Pinrepair, 6 flashes means that it is getting stuck on:
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7th flash - U8 (6821) test for lamp phasing logic test 'B' phase of CPU controlled lamps. Fuse F5 on power supply provides the phase B signal to the CPU board for U8 (6821), U12 (4584).
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Fuse F5 (and everything outside of high voltage section - note that I installed LED displays) is good. All TPs (other than HV) on the power board test out, so it seems that the power board is doing its job. I re-seated the J3 harness on the power board and fiddled with the connectors to see if anything was loose. I no longer get flashes 7 or 8 on the control board when wiggling around anymore.

I tried removing the "flashy" light wiring harnesses from the control board to see if it would allow the control board to boot and I haven't found a combination that lets it get past six flashes anymore.

Where to next? Start testing SCRs on B-phase lamps probably? There may be a short somewhere in the playfield lamps, but I probably need to get the control board to boot up first.

I don't understand. EBC has a 6803 control board, power board, and squawk and talk. Replacement control boards are scarce.

Top of R29 gave me 0 VAC, and so did the wire that goes to J1 - 3. I unplugged J1 and got a "beep" that is the same as I get when coining up the game.
Problem is now that I now get nothing from the control board. Zero LED flashes, completely dead. No more coin up beep. Seems that more things are crashing the farther I go along. Not going to panic yet; I have seen goofy things happen and get worse before and still have a common cause. Maybe unplugging J1 while powered up was a bad idea.

J3 pin 15 on the power board (what I think goes to J1-3 on the control board) is zero volts AC. Maybe that is a hint. Seems it should have 11 VAC. I re-flowed the pin on the board and no change.

I checked all of the TPs on the power board and they are still good. Fuses on the power board are still OK, though I did not test the PF fuse this time.

TP1 - Zero VDC
TP2 - Continuous to ground on cabinet
TP3 - Less than 1VDC, but some measurable voltage
TP4 - Same as TP3.

I am going to go back through the power board this afternoon to see if I can chase the 11VAC. I am interested in what else I need to dig into.

The TPs are on the control board, not the power board. The power board TPs have been testing what they should.

Today, I tried to verify power board voltages and everything is reading high, but I left my DMM on yesterday and the battery is almost dead. I need to replace it and check again

Turns out, I should have completely re-done the power board. I re-flowed it so that the TPS would register the correct voltages, but I couldn't get enough current to run reliably. Once it completely died, I sent the boards to Coin-op Cauldron for a professional to fix. He did a great job and I have been pinballing again for the last 3 months. I could tell he wasn't super excited about 6803 boards, and he refuses to accept modded 6803 boards. I took the battery off of mine and replaced with NVRAM, which I told Clive, and he accepted the challenge. The NVRAM seems to be a common fix that cures corrosion woes down the line. He did a laundry list of little things as well. Now, the electronics just got off a time machine from 1985.

"NOW HIT THE EIGHT BALLL"