loading 1.4.7rc18 killing switches

[Julian]

the PSU is manufactured by a contractor, I will make sure Gerry is aware of this thread and see if he has any feedback to give.

I don't have the ability to test using 'overseas' power here, but I think that'll be the next piece of test equipment I grab, thanks for the recommendation!

[bayamon]

I've received my PSU replacement from Netonix, replaced the PSU on the failing switch and now it works correctly.

With the failing PSU I can consistently repeat the issue: covering all ventilation and let the CPU temp go as high as 70~80°C and then trying to power cycle the switch will causa the PSU to start failing (PWR led will blink and FAN will be on-off in cycles of 5 seconds)

The PSU came failing from factory. The 3 days it worked was because it was cold, the first fails was a warm day. There is no visible damage in the PSU, and if I can make it work in cold temp it will work for many days even with high power usage.

I would suggest make the QA of the switch in high temp conditions. At least this switch will have not passed it.

[sirhc]

This was a known issue which we have reported/discussed numerous times on the forum.

There was a CAP (C51) that is defective.

OPen an RMA, postal mail us the power supply and we will change the CAP and return to you free of charge.

viewtopic.php?f=17&t=2598&p=18205&hilit=C51#p18205

viewtopic.php?f=6&t=2591&p=18176&hilit=C51#p18176

[bayamon]

Im from Argentina, post mail is going to cost almost the price of the PSU.
Thanks for the info, I will change myself the CAP in question and test again.

[sirhc]

Im from Argentina, post mail is going to cost almost the price of the PSU.
Thanks for the info, I will change myself the CAP in question and test again.

C51 is very hard to get to and change. It requires the power supply to be pretty much disassembled and the removal of the white silicon like material.

Even for our repair tech Julian who has changed 100 or so it takes some work and I think he destroyed a couple power supplies perfecting the process.

[bayamon]

Located a SMD CAP C51 in the DRV BOARD of the PSU.

Can you provide me with the specifications of this CAP?

[sirhc]

This is more a Julian question/answer but unless he corrects me change C51 to a 1000pF CAP and you should be fine.

The factory CAP was a 470pF CAP which was right on the edge and this is what caused some to fail and others to work fine.

[Julian]

Offhand that sounds correct for value. It's an 0803 package, if you need a digikey part number, I can get that to you Tuesday once I get back to a computer, unless Chris can look it up sooner.

[bayamon]

1000pf ok, and voltage?

[Julian]

the part we currently substitute for C51 can be purchased here:

https://www.digikey.com/product-detail/ ... ND/3845638