I do not think, that it has something to do with the triacs, these very rarely fail.

Mightbe, this grafic can help you:

WPC-GI (resized).jpg

The GI-Circuit is the most primitive circuit in WPC-machines, but you should search the fault systematically. E.g. how to do this is shown in this thread:

https://pinside.com/pinball/forum/topic/no-fear-gi-connecor-hack-job-now-what#post-2431231

Look at the following grafic (it is for GI-String5, but the same for all other GI-Strings).

To test the Triacs (in my example Q12), apply VCC-potential (VCC!!!) to the collector of (in my example) Q11 (!!!!), in my example testpoint 10. If the string does not work then, Triac Q12 (in my example) is faulty/defective.

Otherwise the error is "in front of" Q12.
Therefore, you apply GND-potential (GND!!!) to IC U1-Pin6 (my example for GI String 5), this is testpoint 11 in my example.
If the string works then, U1 is defective, otherwise Q11 (my example).

You see, it is pretty easy, simply build you a little testcable with an alligator clip - you don not need an logic tester now.

Hope that helps - be careful, not to cause a short when working with your testcable.

Party Zone GI Help (resized).png

Still work in progress, but here you have a schematic for all GI Strings. Hope, that helps a bit

WPC -GI IK2017 (resized).png

What did you replace exactly?

All parts from the kit, including all BRs + CAPs?

if I understand it correct, also all BRs and all CAPs, correct?

OK, but why did you change all parts? Never change a running system !!!!!

Changing these bridges and caps is a very critical and not easy work, and you can destroy more than repair. Now you unfortunately learned it the hard way.

I think, you destroyed one or more of the vias of one or more of the bridges and/or caps.

You should first tell us, what voltages are present, what control-Leds are on?

Here is a good article on pinwiki:

http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Check_fuses_F114_and_F115_message

Connectors and flatcable are sit 100 % correct????

Your cpu-board does not boot, because for what reason ever, you have no +5V. Is F113 OK???

First remove the fuc...g fan and then double check all connectors. Here you see all control-LEDs and all connectors:

http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#LEDs_and_test_points_on_WPC-089_Power.2FDriver_Boards

We must get back your +5V, so check especially BR2 and C5!!!!!

Your ebay link ... good "promotion" by them, but no hint, that it is a hard to to job, it does not help in any way, if the bridges are 35 or 50A in this application and so on ...

It´s late here now, sorry I must go to bed now ... no fear, with the help of the community we will get your board working again ...

Is your connector J101 installed?????

The transformer has NO dc-output and J114 is the connector, where the voltages come OUT from the power driver board to the cpu.

Go here:

http://www.pinwiki.com/wiki/index.php?title=File:WPC089_power_summary.png

and you exactly see, what connectors come from the transformer.

Check at connector J101 the AC-voltages first and post the results.

A.
Meter on AC-voltage.
Measure pin 1 - 2 should be ~ 9.00VAC
Measure pin 6 - 5 should be ~ 13.3VAC

Als check your PMs

Again:

You certainly destroyed one or more vias (through holes) of BR 1 and/or BR 2.

Look at this photo:

http://www.pinwiki.com/wiki/images/0/0f/WPC_Brdg_1and2_Removed3.JPG

You soldered your BRs from the bottom side of the board and all seems OK, BUT on the Top side of the board, you can see traces too, and 2 of them are very delicate, if the vias are destroyed, there is not connection and I am sure, you destroyed the vias.

You must test the BR the correct way, using your diod test function of your DMM.

Think, that there are 4 diodes in the BR and we must test each single diode.

First do it for every diode as follows and post the results:

STEP 1 (resized).png

Second swap red and black lead of your DMM and test each single diode and post the results:

STEP 2 (resized).png

I do not think, that your BRs are faulty.

gmkalos : I think, your board is absolutly repairable with a few new parts and there is no need, to buy a new board.

If you would live in germany, I would invite your for a nice pinball evening and we would play pinball and by the way we would repair your board.

As you are in the US, ask borygard (Rob Anthony) or Chris Hibler, if they are willing to repair your board. The costs will certainly only be a fraction of the costs as for a new board.