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- Analogkid455 10:25AM
- ani_101 10:25AM
- rjj45 10:25AM
- Tom_S 10:25AM
DATS V2 repair attempt - - - > Successful !!!
I accidently connected my DATS V2 to the power amp leads instead of the woofer terminal leads and burned it out. My amp has 32mV of DC offset, so maybe that is what caused it. Or it could be the ground return. The DATS output leads are intended to "float" and connect to the driver only. Accidental connection to the power amp will ground one side and this, in turn, may cause excess current to flow through the output stage. I do not know. The DATS quick start guide clearly warns the end user to disconnect the amplifier when making measurements. So I have no one to blame for this but myself.
Immediately after this mistake occured, I quickly disconnected the DATS test leads from my power amp leads, but I left the DATS plugged into my laptop's USB port. I connected it to my woofer and tried to run an impedance curve. No luck. No "Whooooop" sound from woofer. Got a garbage screen instead of an impedance curve. But I noticed that the plastic case of the DATS was getting very warm. So I snapped the DATS case open. Sure enough, the power output IC chip was getting very hot. Like it had shorted output transistors. And it was pulling the unloaded 5.1VDC USB voltage down to 4.9VDC.
So, I ordered some new output chips from Mouser. They were only about a buck each and they should arrive in a few days. This may or may not fix the problem. Other parts may have been damaged as well. But I figure that I have nothing to lose but a little soldering iron repair time.
I'll let you know if this works.
Comments
Hope it works!
Thanks, Steve! I hope so too.
As I'm still waiting for the new chip to arrive, I decided to go ahead and remove the old chip and clean the pads in prep for the new chip. In the photos below, the bad chip is the one in the middle marked 6111A2:
I used the "two-iron-solder-blob" removal technique. This is a basic surface mount (SMD) removal technique that I have seen on youtube, requiring only basic, inexpensive soldering tools (which is what I have).
But due to my limited experience with SMD, as I was removing the old chip, I accidently pulled off a very small surface mount 1uF capacitor (C13) along with the bad chip (U5).
Luckily, I was able to find the small cap and tack it back onto its pads, so I think I am still in good shape (whew - that was a close one). I cleaned the flux off the pads and board with rubbing alcohol and now it is ready for the new chip.
You might want to invest in a "solder sipper" - they work really well and leave a super clean surface.
Indispensable if you make XO's and recycle parts.
https://duckduckgo.com/?q=Solder+sipper&atb=v350-1&ia=web
I do most of that kinda work with a hot air tool. Clean up with wick, then resolder the pads and add tack flux.
What you did is fine as long as no traces come up with it. Good luck on fixing that thing👍🏼
Thanks for the tips. I have a couple of the old red Radio Shack de-soldering bulbs and a Hakko FR301, but I did not use them here. There was only a small amount of flux and solder on the pads after chip removal, so I cleaned it up with my pencil at a low heat using de-soldering wick. Traces and pads are still in good shape, no lifting at all. When my order comes in, I'll flux the pads, position the new chip, and tack one pad on each side. If the positioning looks good, I'll finish solder all 8 pads.
4thtry said, "This is a basic surface mount (SMD) removal technique that I have seen on youtube, requiring only basic, inexpensive soldering tools (which is what I have)."
You left out the part where you need really steady hands, especially for the tiny caps and such.
Ron
My opinion, Chemtronics Chem-wick is worth every penny.
+1
What's a hot air tool?
Quick 861DW 1000W Digital Rework Station with LCD Display https://a.co/d/coKXKWX
Hot air gun that is used to desolder or reflow electronics. There are pretty amazing if used correctly.
Yup, what Ken said.
We use these, cheap and work fine.
https://www.amazon.com/Quick-957DW-Hot-Station-Watt/dp/B074SBH4G5/ref=sr_1_1?crid=1G5TRSWD211TW&keywords=quick+957dw+&qid=1692709885&sprefix=quick+957,aps,99&sr=8-1
If anyone is interested to buy one... Louis Rossmann has been spearheading alot of "right to repair" stuff.
https://store.rossmanngroup.com/soldering-diy/soldering-stations-hot-air-rework.html
That's the one that I have
Mine is actually a rebuild my uncle did where he used to work. They threw it out, so he played junk man and I got a usable tool.
InDIYana Event Website
Thanks for all the hot air tips. This certainly seems to be the very best way to do this. I'm just trying to get by with what I have on hand. Here is a Mr. SolderFix video showing the method I used for removal (#2) and the method I will be using to install the new chip (#6).
1) Hot Air removal method: 0 to 3:25 minutes
2) Two Iron (solder blob) removal method: 3:25 to 5:19
3) Cut the legs removal method: 5:19 to 8:50
4) Cleaning the pads: 8:53 to 12:08
5) Two Hot Air install methods: 12:08 to 16:00
6) Single Iron pre-load and tack install method: 16:00 to 18:00
Whoo-hoo! Success! UPS just delivered the new chip, I tack soldered it in place, plugged it into my laptop, and got a nice loud "Whooooop" from my subwoofer. My DATS V2 rides again!
My soldering job is a little "blobby" looking, but there are no shorts and it works! I was going to try and "wick" off a little of the excess solder to make it look better, but decided to leave it alone. The new chip stays nice and cool to the touch during operation.
Score! Nothing wrong with that at all.
Forgot to mention an important detail. Mouser sells this chip (Texas Instruments TPA6111A2) in two different size packages: SOIC (8) and MSOP (8). Both versions are 150mW Stereo Audio Power Amplifier chips. The SOIC (8) package has a 4.9 x 3.9mm body with 1.27mm ctr-to-ctr pin spacing. The MSOP (8) package has a much smaller 3 x 3mm body with a 0.65mm ctr-to-ctr pin spacing. Only the larger SOIC (8) package will fit the DATS V2 pad spacing.
https://www.mouser.com/c/?series=TPA6111A2