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Good Morning Group, Finally I have been able to verify that the DIVIDER U5, IC 74AC74 gets hot when I connect the power. Yesterday, I removed the integrated circuit IC U5 (74AC74) and the voltage

Sent email direct -- Gyula HA3HZ

Hello Jose, One other item you didn't mention, would like to look at the power plug and parts around it. It looks like the diode might be incorrect. I checked my build like yours and it was hard to

Thanks Gyula, HA3HZ, for your indications on how to lift the pins of the IC's U6 and U7. I have done so, but the Softrock remains the same, the 5V voltage keeps dropping and I can't find the cause. I

The TO-92 78L05 and TO-220 7805 also have different pinouts. So that also needs to be observed. The 7805, if installed reversed will fail short and feed 12v to the 74logic. This has bitten me more

Hello Jose, One other thing, looks like your jumpers at "J2" need to be crossed over not direct. That isn't the problem here, but I might forget to tell you later. Also I will send you pictures that

Hello Jose, I just got back home. I looked over your pictures. Can you send pictures of your Power plug area. Also pictures of your Si570 close up. I see two possible problem areas. I looked over my

Hello Chuck, I upload the pictures here: /g/softrock40/album?id=269043 73 José María EA4B

Hello Jose, Are you building the 6.3 RX-TX version? I just built another one last week to use in another SDR-Cube, and it works great. I have built many 6.3 and NG versions. If you can please post a

ps.: You can replace the 'Desoldering wire' with a piece of cable that has a multi-core twist or a coaxial cable shield that absorbs tin well. Try this with a separate tin. You can replace the small

Unfortunately, it is difficult to determine a fault location from the images because the cut wire ends are long and bent in one direction. Regardless, I found a reference in the last description that

Good afternoon Thank you very much for your help. In reference to what was indicated by Alan, G4ZFQ: I have used an eyeglass (Loupe) to check all his solder, maybe a solder splatter or a mustache with

Good Morning Group, I have built hundreds of the RXTX boards and usually the freshly built board will play right with first application of power. That is because I do my initial trouble shooting

If you could put a picture, more eyes would see more - maybe we'll find the fault. Of course, if the error is visible. -- Gyula HA3HZ

If the 74AC74 is running hot, then make sure it is not installed backward, or has a solder bridge on the pins. Mike W6MXV

Sorry, I misread the problem. Ignore the previous post.

From the described problem, it appears that the 12V bus is being loaded down. This could happen if T4 has been installed such that it provides a path to ground through L2, L3 & T6.

the values ??being much lower than expected, the two circuits U6 and U7, give exactly the same measurement sequence voltage on its pins:

How does that affect the 5 volt regulator? 73 Alan G4ZFQ

Check the transformers in the circuit, one might have the connections swapped. T4 in particular.