testing a crossover

OK,lets have a go with this,i have asked wilmlow for adivice ,schems and any help they can give me,but they just say send it in to us,and are not coming foreward with any other help,which is a shame,as these speakers were not cheap,for me anyway..
ive checked the AC voltage on both amps
amp driving mid/high which has popped twice, now repaired but running in another system {all good}
readings left channel -0.001v {AC]   right channel -0.001v {AC]
good amp[never popped} runs bass, left channel 0.002v [AC]
                                                            right chan.  0.002v AC
all other components turned off, except amps 
At this point i should add a little more history,after i got the amp repaired and plugged it back into the system,after about 3 hours it went pop again,so i sent it back to the technican,after ttwo days of him looking at it,he sent me an email asking me to checked my speakers,which is when i realised that was where the problem was,so i dont think it is either amps,i now run the repaired amp in another system which seems to be good,so i think the problem is in the crossovers,as all driver read the correct-ish ohms,but what i find very strange,is that both xo s have gone us,this is a puzzle to me.
I am totaly open to any options,but as a retired guy,money is a factor,but would love to find out the fault,but if its easier,i have another two power amps in boxes,but there are lower in power {Arcam Alpha 9p s}.
Another question ,is it not AC at the speaker terminals ?,im not sure!!
I have removed the caps from one crossover{or one lead} and they check out to be ok on all caps,
What do you think maybe  suspect on the wiring,or is it just my soldering ?.
ANYWAY I THANK YOU SO MUCH FOR ANY HELP 
regards Mark
PS if you can give me a day to work out a schem.that would be great.
Mk

Are you measuring the resistance across IP- and IP+ on the PCB? It looks to me like IP+ routes to two resistors (2.2Ω and 3.3Ω), there's lots of clearance between the tracks and no obvious short. So even if there were a problem further down the line you'd expect to see at least 1.3Ω across the inputs. It's rare for resistors to fail closed circuit so I wouldn't go looking there just yet.
The 2.2Ω is in series with the 12µ cap which will block DC, I can't work out what the 3.3Ω connects to under that big cap, but I still can't see how there'd be 0Ω across IP- & IP+. I'm sure I'm missing something.
I can see fibres on the PCB conductors but assume they're hot glue or stuffing material. Even so I'd start by cleaning up the copper connected to IP- & IP+ and measuring the resistance across those if you haven't done so already. I'd also check the multimeter by measuring a known value e.g. a resistor that's out of circuit. You wouldn't believe the number hours I've wasted going down a rabbit hole only to find I've measured something wrong or missed something obvious.

I'm sure you'll get there in the end with the help of some others here... good luck.

No NOT ac voltage, DC voltage. This is the offset voltage of the amp and I wanted to make sure they were low as THAT could be a cause of capacitor failure.

Well if you have lifted one lead of each cap and they test good, I would say it's a short on the PCB. Check all the resistors just to be safe, most resistors open or go high when they fail. In one picture I saw a couple capacitor leads that looked very close together. On another note, you said the amp worked for about 3 hours when you first got it back. So I'm assuming they sounded good when bi-amped before it went pop? I'm thinking there could be physical contact between a couple components lead wires. Reason, it work for a while. Maybe vibration caused the components to get physically close enough to short. What is the value of the cap connected to the midranges in the bi-amp configuration?

For some reason I can't access your crossover photos I saw yesterday. Anyone else have this problem?