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Topping DX3 Pro V1 repair

Joined
Oct 1, 2018
Messages
37
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35
#1
I wanted to make a thread on how I repaired my DX3 Pro V1 and help others repair theirs. I thought I'd start off with a backstory on my DX3 Pro that suddenly failed:

I had a Topping DX3 Pro V1 that failed after 9 months of daily use. I was listening to music when I suddenly heard a loud pop through my headphones (MASSDROP X MEZE 99). There was no sound thereafter and my DX3 Pro was stuck in standby mode. Based on numerous posts from here and other forums about DX3 Pro failures I knew this wasn't a good sign. I was under the impression that since my unit had worked fine for the most part in those 9 months that it would not be prone to this sort of failure. Most DX3 Pro failures seem to happen early on, within just a few days or weeks. At this point I was disappointed but after I reached out to Topping I became very satisfied with their customer service. When I inquired about sending the unit in for repair they responded by saying they would send me a replacement DX3 Pro V1 completely free of charge. Although I preferred black, they only had silver but I was ok with that. I've been using the replacement for 2 months now and it's been working without issue.

At this point I had a spare DX3 Pro albeit non-functional. I'm by no means an electronics guru but I do have plenty of experience with SMT soldering. I figured I'd try to repair it. I suspected the OPA2140 was dead based on this post by TP-Wong. After taking the unit apart I did find pins 6 and 8 of the OPA2140 were shorted by doing a continuity test with my multimeter. If we look at the datasheet we see pin 6 is an inverting input and pin 8 is a positive power supply.

opa2140.jpg


To rule out other components being the cause of the short I lifted both pins out of circuit.
20191209_202648.jpg


After lifting pins 6 and 8 out of circuit they were both still shorted together and other shorts on the same circuit were gone. This indicated to me that the OPA2140 had somehow died and needed to be replaced. From TP-Wong's post it did seem that some nearby transistors might need to be replaced as well. There was also this post by John Hammond that showed a transistor had failed on his unit. I could not find any other shorts on my unit so it looked to me that only the OPA2140 needed replacement. I ordered a replacement OPA2140 from Mouser costing me $10.30 total using their cheapest shipping option:

https://www.mouser.com/ProductDetail/595-OPA2140AIDR

20191225_031623.jpg


Here I've just finished soldering in the replacement from Mouser. After reassembling the unit and powering it on the DX3 Pro came back to life!




20191225_032635.jpg


In my case it was a simple fix but other failed units may also require some transistors be replaced. Here is a close up shot of the transistors with their part numbers:

20191209_201632.jpg


I could not find these transistors on Mouser or Digikey. There are two types and here are links with the correct package size:

2SB649AG = https://lcsc.com/product-detail/Transistors-NPN-PNP_2SB649AG-C-AB3-R-C-100-200_C87883.html
2SD669AG = https://lcsc.com/product-detail/Transistors-NPN-PNP_UTC-Unisonic-Tech-2SD669AG-C-AB3-R_C87301.html

It seems that in some repairs Topping has opted to replace the OPA2140 with a AD8620 instead and it appears this is what they're using in Version 2 of the DX3 Pro. This will increase the output impedance to 4.7 ohm. I'm not sure what Topping's reasoning for this is but the AD8620 can be found on Mouser and Digikey.


In order to open the unit you will need a 2mm x 200mm T-handle hex key:

http://www.carbideprocessors.com/t-handle-hex-driver-2mm-x-200mm-wiha-33436/

I personally bought a set from Amazon that amirm had linked in the DX3 Pro thread. The set includes a 5/64" size which also works:

https://www.amazon.com/gp/product/B...n_title_o04__o00_s00?ie=UTF8&psc=1&pldnSite=1

I hope this is useful for anyone looking to repair their DX3 Pro.
 
Last edited:
Joined
Dec 28, 2019
Messages
3
Likes
2
#2
I wanted to make a thread on how I repaired my DX3 Pro V1 and help others repair theirs. I thought I'd start off with a backstory on my DX3 Pro that suddenly failed:

I had a Topping DX3 Pro V1 that failed after 9 months of daily use. I was listening to music when I suddenly heard a loud pop through my headphones (MASSDROP X MEZE 99). There was no sound thereafter and my DX3 Pro was stuck in standby mode. Based on numerous posts from here and other forums about DX3 Pro failures I knew this wasn't a good sign. I was under the impression that since my unit had worked fine for the most part in those 9 months that it would not be prone to this sort of failure. Most DX3 Pro failures seem to happen early on, within just a few days or weeks. At this point I was disappointed but after I reached out to Topping I became very satisfied with their customer service. When I inquired about sending the unit in for repair they responded by saying they would send me a replacement DX3 Pro V1 completely free of charge. Although I preferred black, they only had silver but I was ok with that. I've been using the replacement for 2 months now and it's been working without issue.

At this point I had a spare DX3 Pro albeit non-functional. I'm by no means an electronics guru but I do have plenty of experience with SMT soldering. I figured I'd try to repair it. I suspected the OPA2140 was dead based on this post by TP-Wong. After taking the unit apart I did find pins 6 and 8 of the OPA2140 were shorted by doing a continuity test with my multimeter. If we look at the datasheet we see pin 6 is an inverting input and pin 8 is a positive power supply.

View attachment 43705

To rule out other components being the cause of the short I lifted both pins out of circuit.
View attachment 43706

After lifting pins 6 and 8 out of circuit they were both still shorted together and other shorts on the same circuit were gone. This indicated to me that the OPA2140 had somehow died and needed to be replaced. From TP-Wong's post it did seem that some nearby transistors might need to be replaced as well. There was also this post by John Hammond that showed a transistor had failed on his unit. I could not find any other shorts on my unit so it looked to me that only the OPA2140 needed replacement. I ordered a replacement OPA2140 from Mouser costing me $10.30 total using their cheapest shipping option:

https://www.mouser.com/ProductDetail/595-OPA2140AIDR

View attachment 43707

Here I've just finished soldering in the replacement from Mouser. After reassembling the unit and powering it on the DX3 Pro came back to life!




View attachment 43708

In my case it was a simple fix but other failed units may also require some transistors be replaced. Here is a close up shot of the transistors with their part numbers:

View attachment 43709

I could not find these transistors on Mouser or Digikey. There are two types and here are links with the correct package size:

2SB649AG = https://lcsc.com/product-detail/Transistors-NPN-PNP_2SB649AG-C-AB3-R-C-100-200_C87883.html
2SD669AG = https://lcsc.com/product-detail/Transistors-NPN-PNP_UTC-Unisonic-Tech-2SD669AG-C-AB3-R_C87301.html

It seems that in some repairs Topping has opted to replace the OPA2140 with a AD8620 instead and it appears this is what they're using in Version 2 of the DX3 Pro. This will increase the output impedance to 4.7 ohm. I'm not sure what Topping's reasoning for this is but the AD8620 can be found on Mouser and Digikey.


In order to open the unit you will need a 2mm x 200mm T-handle hex key:

http://www.carbideprocessors.com/t-handle-hex-driver-2mm-x-200mm-wiha-33436/

I personally bought a set from Amazon that amirm had linked in the DX3 Pro thread. The set includes a 5/64" size which also works:

https://www.amazon.com/gp/product/B...n_title_o04__o00_s00?ie=UTF8&psc=1&pldnSite=1

I hope this is useful for anyone looking to repair their DX3 Pro.

Just thanks a lot. I know that is an excelent unit, but afraid that fail on me. I live in Argentina and here is not easy to find spare parts. So i believe i will buy the smsl m500, i know is more expensive but add MQA support and the pro version of the DAc. Will see. Thanks again for such good info!!!!!!!!! Congrats!!!!
 

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