Noticed an issue when turning machine on, no controlled lamps light up! For about 4 minutes from power on, the lamps begin lighting up in a consistent sequence according to the attract pattern, eventually coming on fully. I recorded this sequence a couple times and determined the last 4 columns to light up were 6, 7, 1, and 3, in that order. That lead me to U18, where the in and out for those four columns are all on the left side of the chip. On U18, those column’s in-out correspond to 3-2, 4-5, 7-6, 8-9, respectively, all on the left side. This seemed significant so I probed U18. From power on, test 9 (all lamps), probe on 5v and Gnd test points, TTL and Pulse, U18-12 (output for column 5, this is one of the early columns to light up) hi and lo were both lit, pulse blinking rapidly. U18-2 had lo lit and pulse blinking slowly. Few minutes later, U18 2 and 12 both had hi and low lit with rapid blinking.

Game is all LED. Other than that it is stock.

The basement temp has gone down a few degrees and this issue resolves after a few minutes, possibly from warming up?

Would the above suggest an issue internal to U18?

Thanks for any help

Bump and update. Reflowed 1,10,11, and 20. Exact same results.

Replaced C4 because it’s easy and I had one.

From power on, attract mode, probing TP2 and TP5, starts off at 4.7-4.75V. As voltage increases over 4-5 minutes, more lights come on. All lights come on around 5-5.02V. Voltage stops raising around 5.03V

I’ve reflowed all relevant connections, I think: J101-1,2, BR2 all, C5 both, C9 both, LM323 all,C4 both, U8 and U19. I’m stumped at this point, ready to buy a new C5 and LM323. Any other suggestions lyonsden ?

Hear ya on C4, it was handy and it seemed a possibles source. The C5 cap sounded difficult to replace from a what I’ve read so I was saving it for last. Driver board is secured with all 9 screws. Wondering if the lights are just the start of the 5V issue, the U9 and U18 are furthest from C4. If you aren’t looking at the lights it would be easy to miss until restarts began. I can do any diagnostics/pics/video if you have any ideas. There is a local guy I’m sure could resolve this, trying to avoid basement removal and gain some knowledge.

Fixed! Couple additional troubleshooting items:
Disconnected J502, J210, and J306 (5V to Sound, MPU, and DMD boards) to eliminate an overdraw from them. No change.
VDC at C9 was ~4.7 at power on so Q1 wasn’t regulating anything
VAC at BR2 was 9.1

After the above, I was down to C5 itself being bad or a bad connection at C5.
Replaced C5 (thanks to msadan for the loaner), added extra wires connectig C5 to BR2 + and -. Popped it back in, controlled lamps come on immediately. TP2 is ~5.04 at power on and raises to ~5.12 after 5 minutes in attract mode.

I don’t have tools to measure capacitance but the removed C5 put out 9V after a battery charge. I reflowed C5 earlier and that didn’t resolve the issue. Can only guess whether C5, the connections at C5 top and bottom, or the BR2 connections were the root cause. My other guess is that in the very near future I would have experienced reset problems due to the low 5V. The slow to wake lamps were just a warning.

Thanks also to lyonsden for your responses.