"raden" wrote in message
...
In message , Adrian Berry
writes
Thanks Geoff,

I'll call you tomorrow.


Modureg - take the loom connector off the pcb and check for a short
circuit (testing the loom also). Something is pulling the volts down on
the pcb output. I don't think that there is a problem with the ign pcb

I would expect to see a couple of kilohms on the modureg


--
geoff

I tested the modureg resistance last night - can't remember the value but it
seemed right at the time, definitely not a short.

One wire from the driver pcb goes direct to the modureg, the other goes to
the ignition board and thence to the other modureg terminal.

The driver board appears to produce about 32V at the modureg output pins and
the voltage seems constant rather than modulating (using a DMM with fairly
slow sampling). This is when the modureg is disconnected and so the board is
driving an open circuit.

The two modureg leads on the ignition board appear to be connected across
the normally open contacts of a relay (not absolutely sure as I don't know
the pinouts).

The relay contacts do not appear to change state when I would expect the
modureg to be operating. I can't really tell if the relay is actuating but
the contacts are remaining open or if it is not actuating at all.

Essentially, the modureg control voltage is not passing through the ignition
board's relay contacts.

Several of the resistors on the ignition board look overheated with the pcb
looking quite brown around them - however the values are stable, no open or
closed circuits.

One of the diodes seemed to present a high resistance in both directions!

I have put it all together for now, CH switched off and the piston that
should be operated by by the modureg is held in with a bit of sticky tape -
not fantastic but at least I have hot water.

I think I need a new ignition board - unless you have any brilliant ideas?



Regards.,
Adrian