Need more info...so how are you testing them? Settings on meter should be AC volts and you have to measure across the windings. For example, across pins 1 & 2 (violet wire pair) you should have approximately 100VAC.

The pinouts are on page 2 of the Williams WPC-95 Schematics Manual.

None of those problems sounds at all transformer related. For the panel speakers I would look for a bad connection between the speakers and the sound board. On the chase lights, I presume there's a chase light board and would start looking there.

Tom, those measurements do look a bit low to me. First, you can try unplugging J605 from the audio/visual board and taking them again. Then plug it J605 back in and look for test points for the +12 -12 +5 and -5VDC on the audio/visual board, you may have to check the WPC-95 schematics to see these points. These voltages are created from these transformer secondary voltages. First, there are diodes and caps to rectify and smooth out the AC and create the +12 and -12VDC that would run the op amps. After that, two regulators create the +5 and -5VDC.

Even if the secondary voltages appear low to me, they are unregulated and could be ok - as long as those DC voltages created from it are not low. I don't have one of these games to refer to, I am only going by what I can see on the schematics. It would also be a good idea to check the AC ripple by measuring AC on the +12 and -12VDC test points on the audio/visual board.

I'm not saying that any of this is the cause of the symptoms you are experiencing, but measurements that are acceptable on the A/V board would help to confirm that the secondary voltages you are measuring are good enough. More input from someone with a WPC-95 would help.

OK. There are no test points, you would have to follow it on the schematics.

Try looking at it from another perspective. If you refer to the WPC-95 schematics (online .pdf) page 1 of 4 Audio/Visual board, there are two separate amps for cabinet and backbox speaker. J504 is the cabinet speaker and J505 is the backbox speakers. They are identical circuits, so if you swap these connectors and the problem stays the same, you would have speaker problems. If the problem changes from no sound on the backbox speakers to no sound on the cabinet speakers, you likely have a problem on the A/V board.

There are 4 discrete diodes that create the positive and negative voltages from the transformer secondary you were asking about, the outputs from the discrete diodes feeds into both the power for each of TDA2030 amplifier ICs (U5 for the backbox and U6 for the cabinet speakers) and these also feed into two regulators to create the +5VDC and -5VDC. Your test points would be the inputs and outputs from those two regulators, a 78L05 for the +5VDC and a 79L05 for the -5VDC.

I can't be certain your problem is the transformer at all - both amps get the same supply voltages but they should still be checked. I would also check those connectors I mentioned. Check the amps (touch them and see if one is getting hotter than the other, just be careful)...it could be a bad amp IC(s). The best way to test would be to inject a signal and check the outs with an oscilloscope. We don't even know if the input audio is correct at this point. The cabinet speaker audio goes through a lowpass filter first before hitting the final amp, and the backbox audio goes through a highpass filter before the final amp. That could be part of why you are hearing what may sound a bit "muted".

Wayout is correct. Your cabinet speaker is crossed over to allow for more bass sounds so it won't carry much else. The backbox are controller by a separate amp and wiring. The backbox only being out is likely either a wiring issue or a dead tda2030 on your board.

None of this is related to your transformer voltage. You're barking up the wrong tree here. Afm saucer boards go out also. They're self contained and replacements can't be found.

Your welcom, Conceptts. Those readings look ok to me. The regulators create that -5 and +5 VDc and they are spot on. If you had problems there, I would suspect the problems with the speakers to be the same between cabinet and backbox. If you did the swap on the connectors like I suggested and the problem "moved" (in other words, changed from the backbox speakers being dead to the cabinet being dead) the best advice to give you would be to replace U5 TDA2030 final output amplifier. It's a "shotgun" wild guess, but troubleshooting beyond this requires some more advanced knowledge and equipment, and I don't have one of these games to refer to to give you more accurate advice.

Good luck with this repair, hopefully a WPC tech or owner can pick up where I am leaving off.

A couple of things I can suggest:

When you operate the TDA2030 from the (recommended) split rail power supply, you must insulate the device from the heatsink using a mica washer or similar.

Remove the failed TDA2030, check the power connections where pins 3 and 5 are. Pin 3 maximum -18VDC and Pin 5 maximum +18VDC. Make sure these are relatively the same, if they are different by more than a couple volts that would be a problem. Also check AC ripple component on these two supplies.

Check output load resistance @ J505 pin 1 to ground. This is your speaker load. Stock speakers with factory wiring?

Check diodes D14 & D15 output protection diodes. In the proper orientation? Lift one leg and diode test in both directions.

Check to make sure C49 and C50 are not shorted. A short on these will feed supply voltages to the IC inputs where they are not supposed to be.

Check C38 DC blocking cap to make sure it is not shorted.

This is all I can see in this circuit looking at the schematics that might cause a problem like this.

Hello pinball fans i have a similar problem with my fish tales at power up it blows the f 602 fuse on my dot matrix display,i have rebuild my hv section all new parts,i put my multimeter on the violet wires of the transformer with no load at all and the reading is 44 v can please someone tell me is my transformer bad because i believe so!!so instead replacing the transformer due to very high cost i decided to order a new transformer single dual output 80v-100vac just for the dmd power up,can some one please tell me if this will work!!thank you all for your help and support.

Hello JIMAKOST,

From the PinWiki site:
"4.17.7 Fuse F601 or F602 blows
The WPC DMD controller rectifies AC voltage via two small 1 amp bridge rectifiers. If a bridge shorts, generally the associated fuse will blow. Sometimes the current draw on the other side of the bridge is so great that the fuse blows too. Whatever the reason, the bridge can be easily tested using the same general bridge testing technique.
The pin layout for these small bridges is different from the larger 35A bridges on the power/driver board.
Begin with your DMM set to diode check, and the red probe on the leg marked with a negative sign as shown in the picture at left. Placing the black lead on each of the AC legs in turn should yield a reading between .5 and .7 volts. If your measurements fall outside of this range, replace the bridge."

If you have further questions/problems it would be best if you start a new thread as to not confuse this one.
Wayout