testing a crossover

between mid pos and neg 2.7 ohms

Okay... before you said that you were getting 0Ω across the MF +/- outputs with the driver disconnected. Is this the same measurement? If it is then it's close enough not to worry about for this exercise. As imhififan said:

The MF measurement should equal to the DC resistance of the 2.5mH inductor + 2.2Ω.".

Take into account there's a bit of tolerance on those resistors as well as the accuracy of your meter.

Not sure what 0.22mH is and also 2.5mH inductor +2.2 ohms,i know what the inductors are but not sure on mH.

Although the inductors will have some DC resistance you can pretty much ignore it for the purposes of this excercise as long as you're in the ball park of the resistor values.

Also i have found that one of the capacitors has a dead short short when tested in dioode mode,{still soldered into pcb},on both x-overs, when the rest show OL,not sure if that has a bearing on anything, just throwing it out there.

If that's the 6µF cap then the reading is correct as it's in parallel with the 2.5µH inductor which will have very low resistance at DC.

If I've understood you correctly then the tests don't seem to have turned up any results that would cause the amplifier to fail.
Maybe someone else will spot something I've missed... or maybe the tech didn't find the real fault in the amp when it was sent in the first time.

i think we may have a misunderstanding some times about ,when i use a diode test and ohms test,i think i haven't explained it well enough,or used the wrong test for finding this fault
originally when i tested the speakers{in the beginning}there was NO reading on ohms for the test when testing the mid/hi speakers on the terminal speaker posts on the back of the speakers,
please see first tests
"          LEFT SPEAKER                                  /
 RIGHT SPEAKER
                speaker terminals with everything connected on both speakers

     MID/HIGH        0.0 ohms                             /
    MID/HIGH    0.0 ohms
       BASS           7.9 Ohms                             /
       bass          6.8Ohms

                                      DRIVER TEST DISCONNECTED FROM X OVER
          TWEETER 8 OHMS                                 /
    7.9 OHMS
              MID 6.3 OHMS                                   /
         6.2 OHMS
             BASS  6.1 OHMS                                /
       6.0 OHMS

     CONTINUITY TEST ON X-OVER WITH DRIVERS REMOVED USING DIODE FUNCTION
                                             between positive and
negative on x over
         HF                  000.2 {dead short}
         /       000.2 {dead short}
         MF                  000.5
              /       000.5
         LF                     OL.
                /        OL.
MID HIGH INPUT IP     OL.                                 /
                OL.
   BASS INPUT            OL.                                 /
                   OL.
                                                  OL. BEING NO CONTINUITY

                               TEST TESTED AT/ON X-OVER SPEAKERS CONNECTED OHMS

         HF 0.0002 OHMS                                      /
              0.002 OHMS
         MF 0.0001 OHMS                                      /
               2.0 OHMS
         LF   6.4 OHMS                                          /
                   6.3 OHMS
what i see,is that when testing a speaker from the speaker cable posts,disconnecting from the amp,i should see how many ohms the speakers are,in this case they are 8 ohms speakers,and i have tested them on other ocassions,after re-wiring them once another time when i re-capped them,just as a check for shorts or problems and they have always read in the ball park of between 7.8ohms and 8ohms,for both bass and mid/hi ,now it doesnt read that,the bass is ok but the mid/high reads 0.0ohms,i only checked them,when my technican asked me to after the first time he repaired the ampand it blew,and sure enough there was a problem,does this throw any light on what your thinking,or have i really badly explained the problem,really sorry if i have.
regards
MK

Okay... I think I am having trouble following. Also there might be a bit of confusion around resistance (DC) and impedance (AC). When you read the resistance across the loudspeaker terminals it has very little to do with the nominal impedance of the speakers (this is even true if you measure across the driver itself). You have a high pass filter on both the mid (12µF) and the tweeter (4.2µF) so if everything is working correctly you should get an open circuit when you attempt to measure resistance across the loudspeaker posts with everything connected.

I’ll tell you what I think I’ve understood and you put me right if I’ve misunderstood:

1) Original test with everything assembled showed 0Ω resistance across the MF/HF +/- terminals on the back of the speaker.
2) Those terminals connect directly to IP+ and IP- on the crossover PCB.
3) With the crossover disconnected the DC resistance between IP+ and IP- was open circuit.
If points 1-3 are correct and you’ve put it back together and measured 0Ω across the loudspeaker terminals then there’s a short somewhere between the terminals and where the wires connect to IP+ and IP-.

4) With everything disconnected from the crossover you measured the resistance across the copper you have marked M+ and M- and got 0Ω.
5) According to the schematic M+ and M- should be connected (at DC) via 2.5µH inductor (of negligible DC resistance) and a 2.2Ω resistor.
6) On your most recent test you measured 2.7Ω.
If point 4 was true then you’d most certainly have overloaded your amp and would have got no sound from the driver... however the most recent measurement shows no such problem.

likklegerry - Thanks for your test data, looks like everything except the Lo and Hi bi-wire connections are in line with what I expected. Just to be clear, with the amplifier and other electronics off, an ohm meter test between the HF+ and LF+ terminals should be 0.0 ohms. Same should be true of the HF- and LF- terminals. This can be measure at the speaker or amplifier terminals.
The diode mode tests at the HF and LF connectors also show what I was expecting.
The dc resistance measurements with the drivers disconnected are in line of what is expected too. Don't worry if it's mH or not, trust us, it is mH.
Which capacitors (value) is showing shorted in the diode mode? The caps themselves should be tested in the ohm mode. I will continue reading an ask questions or make comments as needed.
Please do the resistance test between the HF and LF terminals as described above. This is in the bi-wire configuration with all wires connected to one amplifier.

between the HF+ and LF+ terminals should be 0.0 ohms

do you mean open circuit?.. Not being snarky, just checking :-).

You have made me think of something though... if you forgot to take the shorting plate/wires off the loudspeaker posts when switching to a bi-amp config you could get enough current flowing between the two amplifiers to blow one of them.