03-20-2019 06:04 PM
Theroetacally speaking wouldnt this be a suitable replacement even though it wont fit inside the case?
03-21-2019 07:46 AM - edited 03-21-2019 07:46 AM
I agree the specs of that unit are closer to the stock power supply than the model I chose. My needs dictated retaining the 1RU form factor and POE capacity is not as important but if it were I'd have chosen a larger power supply, possibly the one you have linked.
I don't know what the distribution in the wild comes out to with this issue - do most users do the RMA? Discard and re-order? I should think not many have tried to repair, though certainly there are reports in this thread of just that.
My goal was to find a cheap, easy, repeatable 'fix' that gives you functionality without inserting too much delay. For less than $50 you can have a PS that will work in a few models of switch, fits in the case and doesn't burn the building down (at least so far).
03-23-2019 05:40 PM
Since im going with an external PSU (I dont need Rack mount at the moment) The 4 pin 2 blue 2 black connector (the one closest to the original PSU) is it 24v or 48v? or if neither what voltage is it? Im getting a 500W 48v PSU and im getting a step down converter to go to the 24v inputs.
03-26-2019 07:15 AM
The unit I have here has a POE daughterboard with two 4 pin power connectors (and an empty pad for another), and the mainboard has one. I believe the stock config has 24 VDC into the mainboard connector, 26.5 VDC into the daughterboard connector labelled '24V' and 53 VDC into the daughterboard connector labelled '48V'. I believe the over-voltage is there to account for line-loss.
I'm running 52 VDC into the 48 VDC connector and 25 VDC into the others. I did have one tester report POE fail @ 51 VDC, but everything I've plugged in has worked.
03-26-2019 08:34 PM - edited 03-26-2019 08:35 PM
Comparing the specs, would this be a suitable replacement for this switch?
Using step down converters for the 24v connectors?
04-02-2019 03:37 PM
I've got the exact same scenario - EdgeSwitch 24 - 500 with R5 on the PSU showing the burn. If there are still any replacement PSU's going around I'd love one!! Cheers
04-13-2019 09:22 AM - edited 04-13-2019 09:25 AM
I took a chance at the local electronics recycling shop and bought a US-24-250 for $75 to see if I could get it working again. I confirmed the power supply was shot but I didn't notice any caps or resisters that look bad.
Since POE isn't too important to me I opted for jacobturner's approach way back on the 2nd page of this thread.
I know this probably isn't ideal either since this is meant to be an external power supply but since I'm not even using the passive 24v POE it doesn't seem to overheat. Like @ahpsi I was worried about burning down the building and wish I had a fancy thermal camera like theirs, however mine also hovers around 45c for the last couple of weeks with my load so I'm fairly certain I'm ok.
I opted to try and keep the existing connectors alone so if in the future someone comes up with a better solution I can opt to change it.
Here are some Digikey parts to help people with their repairs:
WM3701-ND are the molex jr fit connectors that connect to the board.
A GST60A24-P1J mean well power supply. Seems to be beefy enough and doesn't get hot, I'm too scared to try passive POE though.
2 weeks ago
Just thought I'd chime back in here. @UBNT-DavidS reached out to me via PM and offered me a replacement switch. I don't have the original purchase reciept because I'm bad at paperwork and David never got back to me about whether or not I was still eligible for a replacement, so I opted to just attempt to repair it myself. I ended up replacing only three components in the power supply, which brought the switch back to life. I had to replace U5 (P/N: TEA18363T/1J), R5 (P/N: NKN2WSJT-73-0R2), and Q5 (P/N: STP10NK70Z). Grand total was about $18 after shipping for two of each of those parts.
About Q5, it looks like that may have been the cause of these issues in the first place. The installed part is `STP10NK70ZFP` (notice the `FP` at the end), which is only rated for 35W. I replaced it with a `STP10NK70Z`, which is rated for 150W. Hopefully this improvement keeps the power supply humming for a great long life!
Thank you for posting this. This helped me revive my US-48-500W. Like everyone else I came home to a dead switch due to a dead PSU two weeks or so out of warranty. Same model and manufacture date. I replaced the three components mentioned above, however it would not power on. Upon further investigation I found two burned resistors R27 and R39. Mine were 1206 20Ω and 0805 2.2Ω respectively. After replacing these my switch came to life. Hope this helps someone else looking to fix this on their own.
yesterday - last edited yesterday
Does anyone know if Ubiquiti is still supporting people whose switches die on them? I have one that had the same failure of the R5 resistor. I would like to get it fixed, and I can replace most components myself if needed. But if Ubiquiti is supporting these failed units still, I would much rather go that route and ensure that the job is done right.