[sdiy] K1 not saving patches

[Aaron Bader]

On Fri, 15 Jul 2005 11:39:06 -0700
Bob Weigel <sounddoctorin at imt.net> wrote:

>
> I have a schematic here if you need to walk through anything. 
>

At this point I could use that schematic!

It killed two backup batteries in a row, immediately suggesting a short
somewhere. I found that two diodes directly connected to the battery -
D1 an D4 - had failed and went open circuit. R9 looks okay but it's
markings are worn off.

The diode failure is interesting as the leads had broken off, just not
enough to be noticeable until I unsoldered them. The negative end on
both as well. Well - D4 did look burned, on the positive end the
silicon was grey instead of orange.

If these two opened up it wouldn't explain the battery getting
discharged. Should I suspect a capacitor somewhere? I don't
know if one of the power supply bypass caps could short the battery.

>
> Was there ever any dropping of this unit that you know of? 
>

Oh, definate. Two corners show some impact damage and the a couple
screw wells near them are snapped clean off.

It was also obvious right out that I'm not the first to poke around
inside this guy. Couple missing screws, some scratches on the board,
broken ground lead.

-- 

"Not a bird not a leaf not a sound/And well after the close of time" 
	--Front 242

Public Key: http://sparked.zadzmo.org/