Re: Gigabyte GTX 1660 super low voltage output on vram

Things that come to mind:

1. Short circuit dragging the rail down
2. Problem with the regulation/feedback circuit
3. It's some parasitic voltage and the rail isn't actually coming on (maybe check if prerequisite rails are present?)

Hi!

I have a weird one for you. I have a H87-Pro4 from Asrock that power cycles. But only when you do a restart after it was already running!

Symptoms in detail:

1. I switch off the ATX PSU for ~15-20 seconds, then switch it back on again.
2. I press power button. The board boots without issues.
3. I can shut down the board any way I want (via OS* menu, or pushing the power button - either in the OS or the boot manager).
4. Push power button again, board boots fine.
5. This shutdown/powerup can be repeated multiple times without problems.
6. BUT: If I do a restart instead

...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed



If they go anywhere, I can't find it. However, I have secured my botch wires with some hot-melt glue, so I can't get to every contact on the board anymore.



Pin 4 doesn't seem to go anywhere. Pin 5 goes to the 3.3V rail.



That it does.



If we rely on the dot on the silk screen to identify pin 1, then it goes to PA0-WKUP (pin 10), and nowhere else, as far as I can tell.



...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed

I think D1 goes in like this (green).

I have continuity from the negative of the beeper to PA3, PA4, and PA5. The positive just goes to the 3.3V rail, as far as I can tell.

Encoder, when viewed from behind, starting in the bottom left corner going counter-clockwise: Pin 1 goes to PB3, pin 2 is ground, pin 3 goes to PB4, pin 4 to PA15, and pin 5 is ground again.

And pin 1 of U3 (TIP_TEMP) goes to PA2.

Disclaimer: I vouch for nothing except my own...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed



Good idea. The step-down module already has a beefy electrolytic on its output, but another... rummages through parts bin... 586nF won't hurt anyone.



As suggested before, it seems to be a JW5026. Or something very similar. The pinout and surrounding components match.



It seems to go from the switching output of the JW5026 (W539) to ground. I'm going out on a limb here and speculate that it could be there to increase efficiency of the buck...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed

Wonderful! That did the trick.

The issue was: The metal contact which got bent in the original incident ended up a little bit... crinkled when I tried to bend it back into shape. That shortened it just enough so that it no longer made any contact with the tip, even when it was fully pushed it.

I attached a sketch to illustrate.

I tried to straighten the contact as much as possible, and now it works! I can even remove the AMS1117. The 5V really were not needed...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed

Thanks again to all who replied.

Thanks to your input, I managed to get a little further. So, first of all: The MCU and OLED seem to be Ok. If I apply 3.3V at what would have been the output of the LD1117AG, the screen comes on and flashes "Error" at me. The broken LD1117 also failed open, not short.

Next I figured: Ok, it doesn't look like the 5V from the buck converter are needed anywhere else. They're really just an intermediate step in the creation of the 3.3V...

Re: Quicko T12-955 Repair (Board Rev 3.3): Help identifying components needed

First of all: Thanks to both of you for replying!



I looked at the data sheet I got from here, and I think the pinout does not match.

The data sheet says that ground should be on pin 5, but it is actually on pin 2. I think that would rule that chip out, no?




That does seem to match better. I got the full data sheet from here and pin 2 is on ground, pin 6 goes to L1 (an inductor), and pin 5 is connected to the red wire (via...

Hello! I'm newbie-ish in electronics and hope you can help me.

I use a Quicko (or Quecoo, not sure which is correct) T12-955 soldering station as my daily driver. Recently, I had a mishap. While changing tips, the metal contact inside the handle got bent and must have shorted against some other contact. Since then, the station only shows "Error" on its display. I fixed the bent contact but the error didn't go away. In fact, now it's completely dead.

After opening it, I found obvious two faults: A chip that looked molten (U5), and another chip which got very...

Re: New Members - please post your introductions here



And, just to prove my own point, I forgot the "not". To not strain everyone's patience.

Off to a great start, am I?...

Re: New Members - please post your introductions here

Ok, complete moron here. The username isn't just for show. I'll try my best to strain everyone's patience too much.