[Boatanchors] Johnson Invader 2000 Help Needed

[Mark Bell]

Gang --

Bad news -- Initial smoke test of my Invader produced.....smoke!

I popped the fuse on the LV Power Chassis and had some smoke coming from the
compartment housing R61 on the Invader.   R61 look cracked, but not burned,
and I replaced it.  The sniff test indicated this was not the culprit, but
it ohmed out at 33 ohms, not the 1K it was supposed to be.

The 300V line on the LV supply was blown, and I tracked it down to the
5U4 -- it tested dead on both sides.  I performed voltage check on the LV
supply before installing another tube, and all was OK.  After the new 5u4
was installed, all voltages from the LV chassis was good (high, but I didn't
have a load on it).

I then proceeded to do the resistance checks as per the manual.  Every
measurement associated with the 300 / 150V circuit was really high.   By
removing the 0A2, I was able to check the 150V circuit and the dropping
resistors associated with it are good.

My problem is the 300V circuit.  With the 0A2 out of the circuit, and all
cables removed from the Invader chassis,  I should see essentially infinite
resistance between the 300V supply of the LV cable connector (J3 pin 5) and
ground.   I'm measuring about 33K ohms.  I get about 39K from 0A2 pin 5
(with the OA2 removed); again, I expect to see almost an open.

I need some help in understanding what could be causing this in order to
know what to look for.

I think there are a few Invader 2K owners on the group;  if so, can you do a
check on the 0A2 pin 5 and let me know what you getting?

Thanks

Mark K3MSB