I have a Super Pro that I have been working with for some time. In think that I mis-mated the USB dongle to COM Port connector. Now I can no longer communicate with the Board. I have another Armmite PRO and I can communicate with that. Also the LED does not light when the board is connected to the USB, but it dies lightm when the board is connected to an external power source.
Can this board be repaired?
-dl
Fixing a blown SuperPRO
Re: Fixing a blown SuperPRO
We don't do repairs, but you may be able to fix it.
So the USB dongle still works with a PRO, but the SuperPRO does not.
The weak link is usually the diodes, which allow power supply steering,
it is located next to the 6 pin connector (SOT-23)
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I moved this set of emails here as it is instructive on how to figure out what has gone wrong on a board.
To echo why we don't do repairs, is that it isn't cost effective. Boards are built in batches with an automated process. To repair one requires a tech to trouble shoot it, and then either fix it of pass it off to an assembler to swap parts. I ran into this a number of years ago with just a home appliance. My wife called me one day to report the garbage compactor was broken, as I was away I had her call a local appliance repairman we used before. He told her that while he could come out an fix it, the service call was $75 and add any parts to that, did it really make sense. A new unit costs $125. So it got put on the honey do list when I got home. I pulled it apart and found the chain drive mechanism had broken, so I ran into the appliance parts store and bought a new one (the new one was metal, old one was plastic). So yes it was fixable, just meant I had to spend the time at my typical 25 cents an hour rate.
So the USB dongle still works with a PRO, but the SuperPRO does not.
The weak link is usually the diodes, which allow power supply steering,
it is located next to the 6 pin connector (SOT-23)
------------
I moved this set of emails here as it is instructive on how to figure out what has gone wrong on a board.
To echo why we don't do repairs, is that it isn't cost effective. Boards are built in batches with an automated process. To repair one requires a tech to trouble shoot it, and then either fix it of pass it off to an assembler to swap parts. I ran into this a number of years ago with just a home appliance. My wife called me one day to report the garbage compactor was broken, as I was away I had her call a local appliance repairman we used before. He told her that while he could come out an fix it, the service call was $75 and add any parts to that, did it really make sense. A new unit costs $125. So it got put on the honey do list when I got home. I pulled it apart and found the chain drive mechanism had broken, so I ran into the appliance parts store and bought a new one (the new one was metal, old one was plastic). So yes it was fixable, just meant I had to spend the time at my typical 25 cents an hour rate.
Re: Fixing a blown SuperPRO
I have an ARMmite Rev 3. Is D4 the same diode as the SuperPro?
Thanks,
Dan
Thanks,
Dan
Re: Fixing a blown SuperPRO
You should verify the diode is the issue, use the schematic and trace the voltage input to the power supply
Some ARMmites use a single diode, usually a BAT54, those would not be the same as the dual diode version of the BAT54C. Check the package marking vs diode data sheet
Some ARMmites use a single diode, usually a BAT54, those would not be the same as the dual diode version of the BAT54C. Check the package marking vs diode data sheet
Re: Fixing a blown SuperPRO
The diode looks OK. It's 3.7 Volts on the input and 3.0 Volts on the output. Something is loading the 5 Volt line.
Dan
Dan
Re: Fixing a blown SuperPRO
Those are schottky diodes, so you are pulling a lot of current through them (the one on the board and one on the dongle). The normal drop is less than 0.4V (you can find this out by looking at the spec for the BAT54C, in Figure 1 of the Vishay version - it show 200 mA for 0.7V). (Digikey is my go to source for all specs, they have a great search engine and PDFs are linked for most parts).
My guess would be the 3.3V supply is toast, but you said it works with external power source, you'd have to describe how you did that, or you need to trace out the voltage.
Sounds like some device has failed (power supply chip, possibly the CPU). I would guess one or more is getting hot.
My guess would be the 3.3V supply is toast, but you said it works with external power source, you'd have to describe how you did that, or you need to trace out the voltage.
Sounds like some device has failed (power supply chip, possibly the CPU). I would guess one or more is getting hot.
Re: Fixing a blown SuperPRO
Just getting back to this. the 78M05 is getting hot. The LEDs no longer light when the board is supplied by any source. I normally use a 7 to 8 volt supply connected to J4.
-dl
-dl
Re: Fixing a blown SuperPRO
It's possible the 7805 is toast, or also possible that the LP2985 is gone (it is the SOT23-5 device just to the right of the 7805) -- yes remind me to put an annotated picture of the board in the help files, no room to label all the components on the silk screen.
Is the LP2985 also hot?
If 2985 seems OK, then remove R13, which connects the input power (from the USB dongle) to the 7805. If the board comes up then, the 7805 is bad, and you can either replace it, or remove it and supply 5V power some other way. (R13 is the 0 ohm resistor just above the 7805)
Is the LP2985 also hot?
If 2985 seems OK, then remove R13, which connects the input power (from the USB dongle) to the 7805. If the board comes up then, the 7805 is bad, and you can either replace it, or remove it and supply 5V power some other way. (R13 is the 0 ohm resistor just above the 7805)
Re: Fixing a blown SuperPRO
The input voltage at J4 is 7.3 Volts with fresh batteries in my test supply. The output of the hot 7805 is 4.8 volts. The output of the HOT 2985-3.3 is 3.0 Volts. The board no longer functions. It could be a shorted Capacitor or bad CPU.
By the way, I'm using a schematic for an ARMmite PRO, not SuperPRO.
By the way, I'm using a schematic for an ARMmite PRO, not SuperPRO.
Re: Fixing a blown SuperPRO
This started off with your saying the SuperPRO was bad, why would you use the ARMmite PRO schematic?By the way, I'm using a schematic for an ARMmite PRO, not SuperPRO.