I need help reviving my sBITX V3
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Hello all,I have been fighting a losing battle in building an enclosure for my sBITX. I then made a really stupid and noob mistake. I use Anderson Power Pole Connectors on all of my radio gear.? I made a pig tail adapter to change the XT60 Power Connector to Anderson PP. I was tired and experiencing extreme back to feet pain so I was trying to concentrate on my sBITX and not on the pain. Apparently I wasn't concentrating enough. If anyone who has worked with Anderson PP, then you know that to have to slide the positive and negative sides together to complete the connector. This is where I screwed up and hurt my baby (sBITX) and I need to bring her back to the joyful life that it shared with me before my stupidity maimed her. Here is a pic of the evidence of my mometory intellectual ineptitud.? So my sBITX was powered up with reverse polarity and it did not like it.??
It is my mistake and I should have caught that but I don't have a DeLorean Time machine to go back and fix it so this is where I'm at.? I contacted Ashhar about it and he tried to help but he is very busy. Here is what we did: I removed the Raspberry Pi 4 and it still boots up on its own just fine I measured the resistance between the positive and negative sides on the XT60 Power Connector.? Here are the measurements: With the power turned "Off" 0.0 ohms With the power connector turned "On" 6.0 ohms Then I unplugged the regulator and made the same measurements OFF - 0.0 ohms ON - 4.1 ohms? Ashhar then told me to replace the IF510 PA Transistors. I did that and performed the same tests: OFF - 0.0 ohms ON - 3.6 ohms Unplugged the regulator OFF - 0 ohms' ON - 4.1 ohms This is where I am now. I do hope and pray that it can be repaired because I became really attached to it and I do not have the ability to replace it. I'm open to any and all ideas. I just have a very basic set of tools but I will do everything that I can.? -- '72 Aaron?
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Jack, W8TEE
The solder flow on the right side of the diode looks "incomplete". Did a ohmmeter check show it's okay> Jack, W8TEEE
On Friday, May 3, 2024 at 05:22:09 PM EDT, Aaron K5ATG <aaron@...> wrote:
I has almost no resistance across D7. I don't much see a black or scorched area but I di see that d7 has some pieces missing and a crack all the way around it.? It doesn't look very happy. So I guess that replacing it is my next step.? Thanks for the help Noel -- '72 Aaron?
-- Jack, W8TEE |
开云体育Start by replacing the diode D7. Look for any electrolytic caps that look swollen on top. Replace if needed. Raj On 04/05/2024 12:16 AM, Aaron K5ATG via
groups.io wrote:
Hello all,I have been fighting a losing battle in building an enclosure for my sBITX. I then made a really stupid and noob mistake. I use Anderson Power Pole Connectors on all of my radio gear.? I made a pig tail adapter to change the XT60 Power Connector to Anderson PP. I was tired and experiencing extreme back to feet pain so I was trying to concentrate on my sBITX and not on the pain. Apparently I wasn't concentrating enough. If anyone who has worked with Anderson PP, then you know that to have to slide the positive and negative sides together to complete the connector. This is where I screwed up and hurt my baby (sBITX) and I need to bring her back to the joyful life that it shared with me before my stupidity maimed her. Here is a pic of the evidence of my mometory intellectual ineptitud.? So my sBITX was powered up with reverse polarity and it did not like it.?? |
开云体育You cant have 0 ohms across power input with the switch off! Please sort out this mystery first. Raj On 04/05/2024 12:16 AM, Aaron K5ATG via
groups.io wrote:
Hello all,I have been fighting a losing battle in building an enclosure for my sBITX. I then made a really stupid and noob mistake. I use Anderson Power Pole Connectors on all of my radio gear.? I made a pig tail adapter to change the XT60 Power Connector to Anderson PP. I was tired and experiencing extreme back to feet pain so I was trying to concentrate on my sBITX and not on the pain. Apparently I wasn't concentrating enough. If anyone who has worked with Anderson PP, then you know that to have to slide the positive and negative sides together to complete the connector. This is where I screwed up and hurt my baby (sBITX) and I need to bring her back to the joyful life that it shared with me before my stupidity maimed her. Here is a pic of the evidence of my mometory intellectual ineptitud.? So my sBITX was powered up with reverse polarity and it did not like it.?? |
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Ok here is what I was able to do for the pics that you requested.?
The pic above the switch is in the on position and I have the red DMM probe in the positive pin at the power connector and the black is in the negative pin of the power connector. This pic is that same as the pic above with the exception that the power switch is in the off position. I got my mother in law to do the hand modeling for me, but it is ok cause she has her license (KF5VBU) ?This pic shows is a close up of the setting on my DMM. This is the location that I found the schematics for the sBITX. It says that they are for the V3 and have been updated around 6 months ago.? I am willing to do any measurement or test that is within my capability. -- '72 Aaron? |
开云体育I noted from your later posts that switch ON only creates a
short. The dead short on power ON is good news. This means D7 has protected the rig. Cut off D7 and check again. If the short goes away then replace D7 and only then power up and check. Raj On 04/05/2024 10:08 PM, Aaron K5ATG via
groups.io wrote:
Thanks for the advice Raj, |
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I'm still stuck with a non working sBITX v3.?
Here is a recap: Replaced both PA Transistor: still broke Replaced D7: Still broke (I forgot to power it up when I had D7 Diode removed from the board, if this is critical let me know and I can do that, I ordered extra D7's) Removed RPI4 and the RPI4 powers up and functions just fine on its own.? When I power the sBITX up nothing happens. I have been bragging about how great this radio is and now I think that it is teaching me a lesson for it. It is transitioning into something really aggravating.? I'm afraid that its repairs have exceeded my ability. I'm stuck and not sure what to do next.? -- '72 Aaron? |
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I have looked at the print and my idea is to check that you have 12v on the 5 volt regulator and then the 5v output?from it as well as the 3.3v regulator. Here is where you can download the schematic if you don't?have?one yet.?? that is where I would start, if you have all the voltages, then it is a deeper problem, if you dont have voltage..check that you have 12 volts on the yellow power cable connector with it unplugged from?the radio. Sometimes we get tunnel?vision and overlook simple problems. On Sat, May 18, 2024 at 5:31?PM barry halterman via <kthreebo=[email protected]> wrote: Arron, check diode D4 a 5.6 v zener. |
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Yes. I would check the power just to confirm you are getting voltge to the radio. Sometimes it is simply a lack of voltage. Then check the subsystem power supplies (5v&3.3v) to confirm they are present too. Most transistors can handle reverse bias but some specialty devices cant. I am not sure if the voltage regulators are able to handle -13.8vdc is why I am trying to confirm their state.? David On Sat, May 18, 2024 at 18:12 Aaron K5ATG via <Aaron=[email protected]> wrote: Barry, |
Aaron K5ATG
Joel Caulkins/N6ALT
Raj vu2zap
WK4DS