[CQ-Contest] TS850

[Dave Hachadorian]

----- Original Message ----- 
From: "Georgens, Tom" <Tom.Georgens at netapp.com>
To: "CQ-Contest at contesting. com" <CQ-Contest at contesting.com>
Sent: Friday, March 23, 2007 2:59 AM
Subject: [CQ-Contest] TS850


> Hello
>
> I am getting ready for WPX from 8P1A and one of my TS850's
> had its
> display go blank.

>From the N6TR TS-850 Repair Page:

------------------------------------------------
Dead Display (from N6RA):

Thanks to KH6DV who pointed me in the right direction, I
fixed my TS-850's dead display.

The problem was a bad 470 microfarad 16 volt electrolytic
associated with an inverter that powers the LCD display.
The cap leakage was not apparent until the cap was removed.
In my case, the cap damaged a circuit board trace, so I also
had to install a jumper.  The damage to the trace was not
visible, so it was hard to find.  The damaged trace
interrupted the power to the inverter.

Oddly, the cap (labeled C18 on my board) is not on the
service manual schematic (page 173), but it is in the
"pictures" on page 174.  For good measure, I replace the
other two electrolytics on the board (two 100 microfarad 16
volt electrolytic caps).
-----------------------------------------------

I had to do this repair once, and I had a more detailed
procedure, but I can't find it right now. I remember that
the cap is on the board right behind the display. It was the
biggest cap on the board, and the circuit
board was discolored underneath after the cap was removed,
but no traces were open in my case. I remember that there
are some handy solder holes nearby if you have to use a cap
with axial leads like I did. I remember that the whole front
panel of the radio flips down (hinges at the bottom) to make
access easier. This is actually a fairly easy repair to do,
as I remember it from about three years ago.



Dave Hachadorian, K6LL
Yuma, AZ