Healing a narcoleptic Cube

[swamprock]

I bought my third Cube (the other two are long ago sold) about 6-8 months ago, and from day one, it has had a few issues. The first was a flaky power supply that would only work after a few minutes under a hair dryer (a typical capacitor failure symptom). I replaced the power supply, but there were other issues. It would only boot one out of ten times (would turn on but do nothing), reboots would never complete, my USB ports would mysteriously disappear and then return later, and other weirdness. I decided to dig it out today and take a close look at the components, starting with the VRM board. Upon inspection, I found corrosion around the header pins (see crappy photo below). I cleaned the area with a small brush and some vinegar, fluxed and reflowed the solder on the pins, then cleaned the excess flux with some alcohol. Plugged it back in, and it seems to have fixed the issues. I've done a number of reboots and power cycles, and haven't since had any problems. I wanted to post this here as something else others can check out if they're having similar problems with their machines.

 

[thenebular]

Always be careful when reconnecting the VRM board. If you accidently short any of the pins you'll probably blow the mosfet at U33 (As I did about half an hour ago.). The mosfet is easy to order a replacement for (or pull a close enough one from a dead laptop), but getting them off the board without a hot air station is annoying as hell.

 

[1042686]

Hey @swamprock what kind of flux do you use? Any particular brand preference?

 

[weckart]

Hey @swamprock what kind of flux do you use? Any particular brand preference?

Amtech NC-559-V2-TF seems to be the favoured flux of many here (dosdude1) and others (Louis Rossmann). I bought some on the strength of recommendations and can also recommend further. Watch out for fakes.

 

[1042686]

Amtech NC-559-V2-TF seems to be the favoured flux of many here (dosdude1) and others (Louis Rossmann). I bought some on the strength of recommendations and can also recommend further. Watch out for fakes.

Thanks @weckart . Is there anything to look out for in the fake product? Looks like a quality product to me. What about flux pens? I noticed a lot of electronics repair channels on youtube using them nowadays. They sure are cheap comparatively. Is it nothing more than economics at play or do they have a place in one's kit?


Very cool that you fixed your cube, @swamprock . Was there a particular alcohol product you used or was it as simple as Q-tips and iso?

 

[swamprock]

Hey @swamprock what kind of flux do you use? Any particular brand preference?

Amtech NC-559-V2-TF, as @weckart mentioned.
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Very cool that you fixed your cube, @swamprock . Was there a particular alcohol product you used or was it as simple as Q-tips and iso?

91% isopropyl alcohol and Q*Tips... that was it. Didn't need much since the flux is such high quality. Cheaper flux makes a huge sticky mess.

 

[weckart]

Thanks @weckart . Is there anything to look out for in the fake product? Looks like a quality product to me. What about flux pens? I noticed a lot of electronics repair channels on youtube using them nowadays. They sure are cheap comparatively. Is it nothing more than economics at play or do they have a place in one's kit?

Familiarise yourself with the genuine packaging and labelling and watch out for not quite perfect tribute acts or plain packaging. Stick to trusted sellers and beware of anything that comes from China, particularly on eBay.

Never used a pen so I'm not the best to ask.

 

[thenebular]

I made my own. Bought violin rosin and dissolved it in 99% isopropyl. Cheaper than anything except the sketchiest Chinese stuff. And I didn't have to wait 3 weeks for delivery.