Another MARSHALL Valvestate 2000 AVT150 Blowing fuses......

[g1]

Well if C141 was ok till the power amp modules were connected, then that must have been what caused the overheating, or the cap was defective and putting the load on it made it go. Anyway, as it overheated and is now bulging, it needs to be replaced.
But one check you should make anyway: disconnect W102,W103 and W104. Measure the AC voltage from W102 to W103, then W102 to W104. The two measurements should be equal, post the results.
Swapping the connectors C189 and C230 would not be a problem. All connectors should be keyed so they can not go in backwards, that would be the only thing that could cause trouble.
For CN102 and CN103, pin 1 is +supply, pin2 is -supply.
With power off, measure voltage from each pin to ground. If there is any voltage, discharge it before connecting the modules.
When soldering the new IC's to the modules, make sure you discharge C2,3,4, &5 on the power module boards before installing the chips.
So, before installing the new IC's on the power board, discharge the caps on the module, then before connecting the modules, discharge the main supplies.

[blearyeyes]

The ac voltage coming off the transformer is 35.1v both sides of the 32v winding and 19.15v from both sides of the 15v volt winding.

[blearyeyes]

If the PSU caps are charged and can blow the ICs, wouldn't that happen when you connected the Power IC cards PSU leads?

[g1]

That's good. The replacement cap was rated for 63V or more, yes?
Discharge everything, replace cap and power IC's.
If you are then tempted to fire it up with the limiter lamp before connecting the power modules, remember you have to discharge again before connecting them.

[blearyeyes]

I checked the PSU voltage hitting the ICs and it is 45.9v. Both connectors.

I haven't changed out C141 yet.

[blearyeyes]

Yes the replacement was the same spec as original. 1000uF 63v 85c.

[g1]

I checked the PSU voltage hitting the ICs and it is 45.9v. Both connectors.

If you mean +46V on pin1, -46V on pin2, that sounds good.

[g1]

The cap is installed correctly. The board has a circle with a large gray portion on the negative side and a big plus sign on the positive.

Might as well double check their markings anyway. Where the board is marked + for C141 should be the ground trace (same trace that neg. terminal of C171 connects to).

[Enzo]

There are more than one type of module. The AVT150 uses one with two connectors. One is a three-pin connector carrying V+, V-, and output. The other is a 8-pin connector for signal input, ground, and the control signals.

And I recall that these have no captive wires anyway.

The two three-pin connectors are wired in parallel, so you could connect either one to either module. After that, you simply have two modules that are the same. So I see no reason it matters which cable went to which module. But in general, if the cables go to the nearest module, that should be stock. They need not cross each other.

[blearyeyes]

So positive probe to pin 1 PSU+VE and negative probe to pin 2 PSU-VE right?

Of course.

[g1]

No, pin1 to ground, then pin2 to ground.

[blearyeyes]

Pin 1 to ground is 60v pin 2 to ground is .9v
I'm using the chassis.

[g1]

I checked the PSU voltage hitting the ICs and it is 45.9v. Both connectors.

I haven't changed out C141 yet.

Pin 1 to ground is 60v pin 2 to ground is .9v
I'm using the chassis.

These statements don't agree. Maybe because you are using chassis ground, if some boards are not mounted, the ground might not be connected to chassis right now.
So find a ground on the board where the main supply caps are and use that. You should get around + and - 46 at the main caps and it should be the same at the connectors for the modules.

[blearyeyes]

So negative and ground are separate. Like a balanced mic connector. Right?

[g1]

Yes, separate from ground, like a mirror image of the positive supply but opposite polarity (negative).