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k9us
Hi I took a 3A fuse out of one of my fuse boxes and some how a 30A was in the 3A box. I should have notice the size. It now has a 3A fuse which might blow but I have all three board out right now. Here is what I have done so far. I first removed the 4 RCA jack on the top board and no change. I removed each ribbon cable one at a time and nothing changed.? I removed the top three board and the problem was still there. The short goes away when I remove the two pin power connector going to the bottom board. Three of the boards have stick on labels with my guess updated firmware. The top board label is 0550 and the 3rd one down has a label 0550, The bottom board as a label 378. With the bottom board out I read?63 & 56 ohms across the 2 pin power connector on the bottom board. Tim ------ Original Message ------
From: "Larry East" <w1hue@...>
Sent: 10/2/2022 6:45:41 PM
Subject: Re: [QRPPlus] will not power up My guess is that the IRF510 output? FET is shorted due to reverse PS polarity or a static surge coming in on the antenna.? It is also possible that the diode that is meant to protect from reverse polarity is shorted.The input mixer may be gone also, but that probably wouldn't pull the PS down.? What size fuse did you put in?? Anything over 3A might not blow if there is a partial short (depending on the current capability of your PS). -- Tim K9US |
