<JediMindTrick> You want to sell it to me </JediMindTrick>

oh wait...wrong game/universe

First: Welcome aboard, Captain!

Second: Make sure you look over the STTNG forum...tons of useful info there.

Third: Don't Panic, its all easier than it looks upfront.

Ok, here we go...

I would like for you to take a picture of every PCB in the head, and would like a close up picture of the CPU board (lower left corner) from the batteries down...including the connectors.

U20 should be soldered, it also should never fail; primary causes of a U20 failure are battery leakage and poor maintenance actions.

Welcome aboard!!

Check your opto boards.
I can bet you have a problem with a cold solder joint on one resistance and or opto emitter receiver, and you have a bad lm339 ic.

Please post a video , or take note what activity happens on switch test. Post a picture and see if some switch is flickering.

Then unplug the opto boards, the one under the pf and the one from the ball trought and do the same test.

And just in case reset your ribbon cables ,

Best regards

talk about ghost in the machine!
Try taking the battery's out to clear any memory odd codes
the game might have first.
Also make sure all the IC chips are total pushed in all the way.
And reset all the ribbon cables.

Agree with reseat all ribbon cables(wide grey ones). Looks like J208 need to be pushed in a bit below the batteries. Doesn't hurt to make sure connectors all around are pushed in all the way.

For the sake of that super clean MPU board, PLEASE get those batteries off the board!!! Either a remote battery holder or consider NVRAM conversion. Not only can the batteries destroy the MPU board, it can also eat away at the connectors below causing the need to completely repin all of them. So, don't wait!!

If other's suggestions don't fix the issue, as was mentioned, I would suspect a bad LM339 on one of the Opto Interface board under the playfield. When strange problems in the switch matrix like this show up, its always best to change out all of the 339's on all the opto boards.

Is TP3 on the powerdriverboard stable 12.0 Volt ?

WOW! What a great looking board set all original WPC boards and original to the machine; you did say this was HUO, and just by looking at the pictures of the head I believe it.

I agree with this to a certain extent. If you just remove the Alkaline batteries and install Lithium batters you will be fine and you can replace them every 5 years without worrying about them; if you really want to install NVRAM that's also a very good way to go. I don't do this much and usually just for STTNG owners, but if you want to go the NVRAM route, PM me and I'll do this work for free.

Onto your issue...this machine has seen so little playtime that I doubt any of your optos are failed, you more than likely have a connection issue or broken wire that happened when the machine was moved.

I would reseat the connectors on the 16 optoboard under the palyfield, all of the ribbon cables as well as the connectors on the coin door interface board; this is to make sure they are all solidly connected after moving he machine. If you can check your +12V on the MPU and on the 16 opto board under the playfield that would also be good place to start.

I'm actually close enough to you that I can make a day trip to help diagnose your machine and maybe provide a pointer or two, at no expense of course; plus I have to admit I would love to see a HUO STTNG machine, I had to guess at some of the finer details on this machine when I did my full restoration. If you are interested, PM me and we can work out the details.

Can you upload a photo the receipt (with information censored)? I'm curious!

Those are both 50v coil fuses. Did you hear any clunks when turning the game on? I would say it's firing a lot of coils at once (which it obviously should not be doing).

I had this exact same condition on my TZ years ago. While playing the machine it would show “open coin door to access menu” I had no current battery corrosion but if I looked very close at U19 and U20, I could just make out some green death around the pins. Washed the cpu off in vinegar and removed the ic’s. Socketed and installed new chips. Never happened again.

You may have overlapped one of the ribbon cables when you reseated (plugged bottom row into top row of pins ). Use a flashlight and recheck your work.

The 12V regulated that powers the switch matrix is derived from your 18V lamp voltage, Check the status of your 18V LED (LED6) on the power board, it's probably out. You can measure this voltage at TP8 on the PDB.

If its missing, remove fuse 114 and check with a meter to make sure its good.

Which one was it?

If LED 1 is not lit, you arent generating your 12V digital, this is needed for the switch matrix to operate, this is also why you are getting ground shorts...just ignore any switch matrix issues until you restore this voltage. If you havent already done so, pull out F115 and check it with a meter.

If you are talking about D1 on the Power board thats very problematic. I would stick to measuring test points for now:

TP 8 should have 18 Volts Unregulated
TP 3 Should have +12V Regulated
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For those following this thread, it was found that the connection point between the 12V regulator output and Fuse F115 was broken; keep in mind this board has never been worked on making this an unlikely and unexpected scenario.

While performing a visual inspection of the 12V regulator circuit, a TINY speck of what I suspect to be dielectric material leaking from the underside of C2 was found; a much closer inspection of this area revealed all legs connected to C2 on the topside of the board have a black appearance, consistent with corrosion under the solder mask. I suspect that the thru holes under C2 are damaged and the trace between the regulator output and capacitor C2 has fractured.

The regulators output transitions from the top side of the board to the bottom layer through the positive leg of C2 as in the picture below.

Note, this picture is NOT of the damaged board.
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Great!!! Happy playing now. And don't hate too much the left oulane

Left outlane? It's the right one that's brutal! That reminds me, I need to order the lane extender.