Found Shorted Mosfet TSF5N60M In 3 Amp 12 Volt Power Adapter

By on October 13, 2017
how to repair and fix dreambox power adapter

 

 

 

 

 

 

 

 

 

 

A year ago I had replaced my DM800HD_pvr satellite receiver by a model Sunray4 SIM2 800HD_se with Wifi. (by-the-way: the Wifi dongle is internally connected to the front USB port that can’t be used now!). It worked fine but the SIM2 original Chinese software that was replaced by a better European image (in order to be able to scan the European satellites instead of the Chinese ones) for unknown reasons still wasn’t working at the right local time. And it kept displaying the wrong time although the right Time Zone (Brussel, Amsterdam) was set.




Therefore the Sunray DM800HD_se couldn’t be used with the EPG recording timer and only worked after starting a recording manually on time. Probably another reason why not to buy these Chinese Clone Dreamboxes.

Because backing up the image was already been done successfully previously, I decided to try another better suited image. Sadly after two days of effortless trying all sort of images, I noticed that flashing kept failing. And the Sunray Flashup program rapported a memory error in sector 3. And even flashing with my unregistered free Yassinov’s great Optiflasher program now failed everytime.

Because my receiver was useless without a new successfully flashed upload I opened my reciever to see if I could find anything wrong. And I noticed that the internal Fan didn’t rotate and probably because of it the internal mainboard and tuner board chips got quite hot now.

I then checked if the 3A 12V power adapter got hot, but it wasn’t. And after I pulled the plug out of the Sunray DM800HD_se and measured the output voltage it was fine.

But just after I had re-attached the power adapter into the receiver I heard a bang coming out of the power supply. And the green led on the supply had stopped working.

How both problems are related I can’t say, but after I tried my Sunray with another good 3A 12V adapter it worked fine. But the receiver still wasn’t successfully flashable. Sadly my Chinese supplier reacted by telling me to try my Sunray receiver with another power adapter, and that was the last I heard from them. Anyway none of the internal Sunray e-caps were bulged, and none of the components were showing signs of burns or defects either. So this repair is that of the defect original Dreambox 3A 12V power adapter.

power adapter repair

After I checked the power adapter I found several defect components on its board. Following parts were defect and need replacement: 1 x Mosfet TSF5N60M completely shorted, 1 x open Fuse T2A/250VAC, 1 x bulged e-cap 1000uF/16V, 1 x Diode rectifier bridge KBP206 on the primary side, and one resistor with color code blue-gray-silver-gold (0.68 ohm ?, I will come to that later). And it looks like the resistor (1W) had blackened the Alu cooler plate of the Mosfet, which could somehow have short circuited if the resistor made contact with it.

Below the HV 400V 47uF (just 400V seems very low? normally they are 450VDC) primary e-cap there also is a 8dip CR6850T PWM controller chip on board. And that chip is destroyed too in the process and measures fine between Gate and Ground but completely shorted between pins 2 and 8 (Vdd and GND) . And like in most of these cases Mosfet and PWM controller are destroyed simultaneous and both must be replaced.

cr6850t ic

So now I had to order these parts and wait.

These ‘green’ PWM chips apparently are very easily destroyed because I noticed I could order 100 of them for just about 12 Euro at free shipping. I only ordered 10 of them for 1.18 Euro and also 50 optocouplers 4pin type 817 for only 1.53 Euro free shipping because they are frequently used in this and almost all other portable power adapters.

By-the way: Optocouplers didn’t exist yet in the 70s, so many projects were destroyed because there was no safe galvanic separation from any HV circuit part possible. So these optocouplers are a very big improvement that makes all power adapters and all other consumer electronics safe.




About the 0.68 ohm 1W resistor I previously was speaking about. The 4-band code checked with the android app Elektrodroid gave exactly 0.68 ohm as result. So no weird answers there, but when I received the ordered new 0.68 ohm 5-band resistors the code didn’t match any color code table. Something that on previous repairs from others on Jestine’s blog was no rare incident.

See next photo that shows the 0.68 ohm 5-band color code that Elektrodroid nor any other colortable can calculate. Because the brown color band doesn’t exist in the 5-band tables. Of course I measured the resistor value with my Blue ESR tester and it was exactly 0.66 ohm. Which is including any tolerance just fine!

tsf5n60n fet

Above Photo showed the defect Mosfet with the black spot on the coolerplate where the 0.68 resistor must have touched.

Today after almost 3 months of waiting (!) on my eBay order on the long awaited Fqpf5N60C N-channel mosfets they finally had arrived. And the kind seller likely may have sent me another pack of 10 of those mosfets because I had explained they had not yet arrived within the previous 2 months. And in case they do arrive a second time I assured the seller that I will give him notice and pay for them too.

The first thing I did before replacing the aluminium cooler plate with the new mosfet on it, is insolate the leg of the 0.68 ohm resistor. Because that must have been causing the short circuit that destroyed the Dreambox 12V 3A DC power supply. (See the black spot on the previous photo of the cooler plate with the old completely short circuiting mosfet on it).

how to fix power adapter

Above photo shows the re-inserted cooler plate just before soldering the 3 mosfet pins

and 1 coolerplate pin back in. Below the handy 60W light bulb I use in my tests.

series light bulb trick

And previous photo shows that the green led is working and the supply is giving 12.26V again. Job done!

So to summarize, I replaced the 8 dip CR6850T PWM controller chip (10 for only 1.18 euro), the completely shorted Mosfet TSF5N60M , 1 open Fuse T2A/250VAC (50 x for only $1.80 ), 1 bulged e-cap 1000uF/16V, 1 x Diode rectifier bridge KBP206 on the primary side (only $0.99 for 10 of them), and one resistor with color code blue-gray-silver-gold (50 x 0.68 ohm 1W for 2.24 euro). And my Dreambox 12V 3A power supply was perfectly working again with all parts used just costing about 53 cents total. So another repair at almost no cost, and with a lot of spare parts left for next repairs!

dt9205a multimeter

Opening and placing back the top case of the box was easy as above photo shows. Also notice the transparent small bag with the remaining new 9 Fqpf5N60C mosfets (only $2.29 for 10 of them).

About my Sunray SR4 D11 revision board Dreambox repair: in the meantime I ordered one 64Mbit x 8 Nand Flash chip that is going to replace my bad flash chip that is causing the Image flashing error(s). And the not working internal cooling FAN is probably caused by a small SMD mosfet that must be replaced that switches the 12V DC voltage to the plus of the 4 FAN wires. Which is placed at the solder side of the board.

See next photo of the solder side of the Sunray rev.D11 Dreambox board (that can be bought new without the Dreambox SIM2.10 chip for around 75 euro).

The Red circle shows the legs of the 4 pins of the Fan connector. The Blue circle must be the mosfet that is defect on my board and needs to be replaced. And the last photo of my Sunray SR4 rev.D11 Dreambox satellite receiver board shows the Nand chip on the component side that causes the Image Flashing errors why my Sunray fails to Boot. (1 x Hynix H27U518S2CTP for 3.39 euro)

how to repair dreambox power adapter

dreambox power adapter repair

Because I use a couple of Dreambox recievers at home that I need to be able to flash/reprogram, I recently also bought the licence for Yassinov’s Optiflasher Pro 3.0 Ultimate + the E2USB PACK-A1 program. The No CA repair program NCF-SIM2-v3.0 already worked many times splendidly for free, and so did Optiflasher. But if you want to restore/reflash any bricked Dreambox satellite receiver with a new image you better use the licenced versions from Yassinov which will enable you to download the correct Dreambox Images online right into your Dreambox.

And I bought the Full licenced Optiflasher program especially because the program apparently also is capable to Recover Sectors of bad Nands. Something that sadly also requires you to be connected to the internet because also this only works online! And as I wrote need now to recover my unflashable Sunray receiver.

The major disadvantage of both programs however is that the licence key only works on the PC where the key request ID was generated on. So the program is not portable. And if your PC fails one day beyond repair, you probably will loose the (both programs together cost $30/30 euro) licenced versions.

And that is just the problem for me at the moment because the desktop PC that is hooked onto my Router and my Dreambox receiver has no online connection. And because I only have an online connection on the PC in only one of my rooms, on which I have the Licenced (registered) Optiflasher version installed, I have to move to entire Router network from my living room to my bedroom. And that is not at all what I expected as a registered paying customer.

I do hope to easily solve this problem so I do not have to carry my entire LAN network to my bedroom. And I have to ask Yassinov if he has a solution for a honest buyer like me to avoid loosing my registered programs in the nearby future and to make my licensed programs portable.

Albert van Bemmelen ,Weert, The Netherlands.




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Note: You can read his previous repair article in the below link:

http://jestineyong.com/electronics-timer-repaired/

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27 Comments

  1. charles

    October 13, 2017 at 2:26 pm

    Thanks Albert for the detailed report and photos I like the way you always elaborate your repairs because I learn a lot and thanks to Jestine as well for newsletters.

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  2. Parasuraman

    October 13, 2017 at 4:31 pm

    A very good informative article!

    Likes(1)Dislikes(0)
  3. Albert van Bemmelen

    October 13, 2017 at 4:50 pm

    Thank you Charles and right you are. Jestine's Blog is a great place to learn new things from other repair engineers worldwide. And it helps us to save a few bucks not having to spend money on a new device at the same time too.

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  4. Albert van Bemmelen

    October 13, 2017 at 5:06 pm

    In case anyone is interested about the 50 new (plastic) fuses I bought cheap to replace the original defect glass 2A/250VAC fuse, here is the Aliexpress link:

    https://nl.aliexpress.com/item/50pcs-Cylindrical-fuses-2A-T2A-250V-382-Cylindrical-plastic-fuses-LCD-TV-power-board-commonly-used/32754155642.html

    Apparently they are even cheaper now at $1.55 for 50 of them! And they fit nicely in place of the original defect glass fuse.

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  5. Robert Calk

    October 13, 2017 at 8:28 pm

    Good job, Albert. The brown 5th band means 1% tolerance.

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    • Robert Calk

      October 13, 2017 at 8:34 pm

      BTW, 0.66 Ohm would be out of tolerance.

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      • Albert van Bemmelen

        October 14, 2017 at 12:32 am

        Thanks Robert. I think since the tolerance of the original resistor was much higher being 5% according to Electrodroid, the value would be at minimum 0.646 ohm which is well within spec.

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        • Robert Calk

          October 14, 2017 at 7:04 pm

          Maybe so, Albert. I would not trust it because it was supposed to be 1% tolerance. Maybe Mr. Yong will say if you can trust it since he has much more experience than I?

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          • Jestine Yong

            October 16, 2017 at 11:03 am

            For switch mode power supply, a slightly lower low ohms value is acceptable and the circuit will works fine.

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          • Robert Calk

            October 16, 2017 at 1:29 pm

            Yes sir, I know that. I meant can we trust the resistor being out of 1% tolerance and use it in place of a 5% tolerance resistor? I would throw it away since it is out of tolerance thinking that it may not keep the value that it has very long. Anytime any new resistor is out of tolerance, I throw it away because I don't want to take any chances on it and they are not very expensive.

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            • Jestine Yong

              October 17, 2017 at 9:16 pm

              Hi Robert,

              If the resistor is 0.68 ohm 5% and a new one which is 0.68 ohm 1% and the value is slightly out of the 1% tolerance, in my opinion it still can work. It depends on your preference, if you think that this particular resistor will give problem in the future, then replace it.

              Jestine

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              • Albert van Bemmelen

                October 17, 2017 at 10:46 pm

                I can't confirm that the new 0.68 ohm resistor was 1% Robert because I couldn't find any matching 5 Band color table. And I never did say it was 1% but apparently you found a color table that explained the 1% tolerance. (I would be happy to know where that 5 color table can be found).
                Anyhow even if the replacement was also a 5% tolerance resistor, it still is high enough to match the lowest value of the defect resistor. It is with being 0.66 ohm (measured with my Blue ESR meter) never too low to not match at least the original 0.68 - 5% value. Which is 0.646 ohm.

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                • Robert Calk

                  October 19, 2017 at 12:12 am

                  Hi Albert,

                  You said it was brown. Brown = 1. I have a chart that came in a resistor set I bought made by Velleman. Also, I have an app for Win8 that works also with Win10 called Electronic Toolbox that also says so. The app works for resistors up to six bands. It's a great app and I highly recommend it. It has nearly everything you can think of.
                  I was just wondering if we could trust the resistor since it was supposed to be made for a 1% tolerance.
                  If any of my resistors are out of spec, they go straight into the trash. The way I look at it is, why take a chance? Resistors are not very expensive. But If you trust using them then that is fine.
                  I was curious to see what Mr. Yong thought about it. Me personally, I will still through them away unless I just have to use the resistor that is out of the tolerance that it was made to be in. But that's just me. I'm picky.

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                  • Albert van Bemmelen

                    October 19, 2017 at 7:10 pm

                    I understand Robert but I really dont think they are 1%. In my 5 Band color code table, brown just doesn't exist. In Electrodroid it does not and others seen on the internet neither. But I will have a look on the color code sources you mentioned if I can find those. Thanks.

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                    • Albert van Bemmelen

                      October 19, 2017 at 8:21 pm

                      On this very good link I found a couple of useful matching 5 color Band code tables Robert (I started looking on Velleman Color band code):
                      https://www.sampletemplates.com/business-templates/resistor-color-code-chart.html
                      Apparently Black-Blue-Grey-Silver-Brown indeed exists written as 068 x 0.01 at 1%. So you were right about the 1% Robert. Most 5-Band Color Tables like in ElectroDroid apparently were incomplete or just wrong. But I do not think there is any reason to throw away a good replacement resistor if it deviates a little from the on the resistor itself given tolerance. (They are probably just manufactured with a little more off-set value than intented. Which they probably do by cutting into a rotating resistor while calibrating with a laser.) And I doubt that the resistor value will change in its lifetime from that measured value. In this case from the 0.66 ohm I measured, even if its value is a little out of spec of the color marked tolerance.

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                    • Robert Calk

                      October 20, 2017 at 8:18 pm

                      I'm glad you found some good tables, Albert. I still highly recommend the app "Electronic Toolbox" to everybody that has Windows 8 - 10. I'm not sure if it will work with Win7. It has all kinds of great info, calculators, scientific info, and info on connectors and everything you can think of. I think it was only about $5 USD but I don't remember for sure, but get it. It will be the best $5 you ever spent!
                      Yeah, I agree with you and Mr. Yong that since the resistor is within the tolerance that is required by the circuit that it should be fine. But I do not trust anything that isn't what it is supposed to be. So I will continue to throw them away.

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                    • Robert Calk

                      October 21, 2017 at 9:59 am

                      After checking, the app Electronic Toolbox is $5.99. But there is a free app called RS-Toolbox that has some good stuff and a resistor calculator that goes to 6 bands. But the Electronic Toolbox is much better.

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  6. Geoffrey Wight

    October 14, 2017 at 5:52 am

    Albert,

    Thank you for the article. As others have expressed, your detailed account helps to understand the intricacies involved in the finer side of electronic repairs and how to analyze their varied sorts of breakdowns.

     I have found flashing devices to be problematic at times. Every device seems to have it's own set of protocols. 

    You give an in-depth approach to curing a complex riddle of errors.

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    • Albert van Bemmelen

      October 14, 2017 at 10:00 am

      Thank you Geoffrey. These Nand and other flashing devices indeed take a lot of time to fix in case of image flashing poblems. In case of USB memory stick problems there exist a lot of special flashing tools that differ depending on what USB memory controller is used. Chipgenius v4.17. is a good tool to extract the information from those USB sticks. See this link: http://www.usbdev.ru/files/chipgenius/
      Sadly my Sunray Dreambox Fan and Nand flashing problem is not caused by a defect Mosfet or defect NPN gate controlling transistor (A1 smd code, measured HFe was 158). Because both were fine. Maybe it is the controlling processor that controlls both that is defect. But not until I've received the Nand and after replacing the old one I will be sure about that.

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  7. suranag Electronics

    October 14, 2017 at 4:30 pm

    hi Mr.Albert,
    Nice Repair job.

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  8. mahmoud_tajpour

    October 15, 2017 at 3:48 am

    Hello dear Albert your useful and wonderful information was great it was very helpful for me thanks a lot.

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    • Albert

      October 16, 2017 at 10:35 am

      Thank you dear Mahmoud. It is always wonderful to hear that the article was very useful and served its purpose!

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  9. Alexan Catalin

    October 19, 2017 at 6:42 pm

    Hi, dear electronic experts of Jestine's site,

    I have found in a power supply the integrated circuit "CR6331". "G" capsule, SO7. I don't have found datasheet, can anyone know ?

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    • Albert van Bemmelen

      October 22, 2017 at 3:52 am

      Sorry Alexan, i couldn't find any datasheet with that name. However sometimes it helps to look for that number with other prefix like T6631 or MAX6331. Maybe it gives you the required information, see: http://www.tmtech.com.tw/DB/upload/LIST_FILE201010195658.pdf or
      http://www.iatiat.com/pdf/AT6331-Rev1.0.pdf or
      http://pdf.datasheetcatalog.com/datasheets2/39/398171_1.pdf or
      www.cnledw.com/inter/download.asp?file=2012020210533865550.ppt
      Good luck with your repair!

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  10. Justice

    October 20, 2017 at 6:55 pm

    Interesting and exciting to read through, keep up good work Albert.

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  11. Albert van Bemmelen

    October 20, 2017 at 8:37 pm

    Last interesting update, about my Dreambox Sunray SR4 rev.D11 repair: It now WORKS like a completely new Satellite receiver again!
    After I hotfixed the CPU controller chip (removed the cooler on top first!) and I had replaced the mentioned 48 pins Nand chip, the Sunray is flashed successfully and even the Fan works again!!
    Removing the old Nand was the hardest part because 2 copper tracks broke off from the top layer board in the process. But luckily I managed to reconnect those onto the new Nand flash memory chip with 0.2mm wire and my smd solder station.
    Keep in mind that there are other revision Sunrays like rev.D4 that doesn't have a SIM 2.10 ROM but a Ferrari chip, which means that also if your Dreambox is successfully flashed it only works with the right SIM/Ferrari ROM chip card. If I for instance boot my rev.D11 Sunray with a Ferrari chip it creates a NO CA Failure and looks like a bricked machine! My rev.D11 as was explained only works with the DM800HDse SIM2.10 chip card! So you know what to do and what to expect if your Dreambox also has image flashing errors and a Fan that doesn't rotate anymore. The only thing that rests me to do is gluing back the Cooler onto the Dreambox Cpu with special Thermal Conductive heatsink plaster. See this link: https://nl.aliexpress.com/item/Thermal-Conductive-Heatsink-Plaster-Viscous-Adhesive-Compound-Glue-For-PC-GPU-IC-smt88/32739108365.html

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  12. Yogesh Panchal

    October 20, 2017 at 11:58 pm

    Albert,

    Nice article ! thanks for sharing.

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