RE: Cracks in EDP (question for Kim)

["future perfect" <artists@hazardfactor.com>]

I ordered the voltage regulator from DigiKey, and put it in, but I am
getting some weird results. Either the display flickers a few times and
turns off completely, or a few LEDs just stay on. This is on a short
power-up after I put in the part- methinks I screwed up somewhere.

I took #'s u40 & u28, as well as the heatsink out
The new voltage regulator will only fit in one way, with the 'blank PC
board' side facing the front of the unit.
I am guessing "pin 3, on the right when looking at the front of the part" 
is
pin3 on the right with the blank side facing me. Let me know if it makes
sense what I did, and please tell me where things went horribly wrong.

thanks!
Dave Eichenberger- guitars.loops.devices
http://www.hazardfactor.com




>
> You need to change the two +5V linear regulators at the back of
> the unit to
> a switching regulator. These are 5 volt regulators U40, and U28. When you
> take the top off the echoplex, they will be the two in the back
> attached to
> the heatsink. These power two 5 volt digital sections.
>
> The part used in current Echoplex production to replace these is the 
>Power
> Trends (http://www.powertrends.com/) PT5101N 5V switching regulator. You
> should be able to get this part from Digikey (www.digikey.com). This part
> is a drop-in replacement for the standard 3-pin linear
> regulators, and they
> work great. You can actually use one of these to replace both of
> the linear
> regulators, and it works just fine. This is what they do in
> production now.
>
> You need to take the PCB out of the chassis to do it. To do that, unscrew
> the front panel, unscrew the pcb, unscrew the heat sink from the back, 
>and
> remove the nuts from the jacks on the back. It should pop right out. What
> you want to do is unscrew the regulators from the heatsink. Desolder and
> remove both U28 and U40, the linear regs. Take the heat sink out
> altogether
> since it will be in the way, and you won't need it anymore.
>
> Solder the PT5101 into one of the regulator spots (the left one is a good
> choice). The PT5101 is pin compatible with the linear regs, so
> there should
> be no trouble with that. Now solder a wire from it's output pin (pin 3, 
>on
> the right when looking at the front of the part) to the output hole (pin 
>3
> again) for the other regulator location. Use reasonably thick wire,
> probably 18 gauge is ok. This way the PT5101 will be supplying power for
> both the +5V rails the old regulators powered. Put the PCB back in the
> chassis and screw it back together. Now power it up and make sure
> it works!
> You should see the Echoplex runs practically at room temperature now, and
> hopefully that cures the trouble.
>
> Let me know if you have questions.
>
> kim