"aarpay via ElectronicsKB.com" u36611@uwe wrote in message
news:76af1547ad2b4@uwe...
I'm sorry, but I'm a bit of a novice....

Should I be testing the voltage difference between pins 1 and 14? What is
the
reference? Thanks

Arfa Daily wrote:
Hi all,

[quoted text clipped - 11 lines]
it?
Thanks.

Check for +28v on pin 14 of IC502. If missing, safety resistor FP549 is
open. Failing that, you've probably fried IC502. I've got the relevant
part
of the schematic as a pdf if you need it. Contact me off group with a
valid
e-mail if you do.

Arfa

--
Message posted via http://www.electronicskb.com


The reference is ground ie any piece of metalwork on the unit such as the
antenna socket outer, which will definitely be ground. However, I must say
that if your level of expertise with this equipment is actually such that
you are not aware that ground is the standard reference point unless
otherwise stated, then it is unlikely that you are going to be able to
troubleshoot the unit to the point of being able to fix it. Also, you should
be aware of the safety angles of working on a piece of live equipment.
Whilst the 'HT70 is better than some for safety in that it uses a linear
rather than switch mode supply, there is still exposed line voltage in
places around the power supply, so do take care ...

Arfa