Progress

Dan
I have resoldered all the sockets, replaced all the 4700 caps, and some of the mossfets, ( I was given IRFZ 34N as a direct replacement for the IRFZ34 I assume these to be OK, or not ? ).
I am running all axis at 1amp (no heatsinks fitted) with a 2 1/2volt 4 1/2 amp test motor, I have changed the ICs from axis to axis with no difference in performance, so assume all of these to be OK, or all U/S

Z axis
On the B b side of the axis, the 2 9Z34s get hot very quickly, while the 2 Z34s remain cold, (running at 1amp), the 9Z34s and Z34s on the A a side of the axis remain cold, (see later comment on 13FR100 Resistors)

If you hold the bases of the 2 9Z34s on B b side when running the motor slowly you can feel the current, you cannot feel this on the 9Z34s of side A a .
and the motor is erratic and sounds rough.

X axis

All 9Z34s get hot very quickly, and you can feel the current off them as in the above. Motor erratic and rough

Y axis

Still nothing running at all, but the PBL 3776 gets warm after a while ?


I have tested all the OHMITE resistors, I have 5 which read 0.5 ohm on the 200 ohm scale, which is the same as joining the two probes together ie. no resistance, on the other one I cannot get a reading.

Refering back to the Z axis
The Ohmite resistor on which I cannot get a reading is on side A a the cold side of the axis, could it be that I have 5 reistors u/s ?

I have tried to get these or equivilant resistors here but no luck yet.


IF ANYONE IN ENGLAND KNOWS OF A SUPPLIER, THE RESISTORS ARE 3 WATT NON INDUCTIVE AND MARKED AS FOLLOWS


OHMITE
13FR100
0.10 OHM 1%

Best Wishes
Peter Smith