Dreambox 800 PVR Satellite Receiver Repair
This repair is about a dead Dreambox 800 HD PVR that one day refused to work. Plugging in and or turning the adapter Plug made no difference. And after I had tested the 3A 12A Power adapter it worked splendidly. So the problem was within the DM800 HD PVR itself.
And after I had opened it and had examined the pcb and the components they all looked fine and there were no bulged e-caps either. Because it was working again afterwards I reassembled the DM800 HD PVR, and it kept working for the next couple of days. Until it refused to Boot again, so I disassembled the PVR a second time. And this time I removed the entire board to examine it more closely.
Previous photo showed the disassembled parts, and next photo shows the component side of the pcb that looked fine but still didn’t work. Followed by a complete view of the solder side of the board. And I reconnected the Power adapter to see if something got hot, like a capacitor that had changed into a resistor. But nothing got hot. And nothing smelled burnt, and no tracks were bad either.
I also started pressing carefully on some of the board’s parts and spots, and suddenly I noticed that the DM800 HD PVR started running. So it just had to be some kind of bad connection on the board. I looked more closely at the power adapter input. It had 2 grey looking resistors and one of them looked like it could be cracked, I removed the Power and started measuring. The left grey coil or fuse was about 0 Ohm and intact and was the +12V input of our Power Jack.
And the right one with the possible cracked ‘core’ measured fine being also 0 Ohm and was the GND Input of the power jack.
To find out if this fuse or coil indeed was broken I used my Solder iron to see what happened after I had removed that component. And right after it was desoldered it looked broken but also couldn’t be resoldered on one of its sides because it was blackened afterwards. On that component’s side the shiny solder had gone. So it must have been causing the power problems!
Next photo shows the fuse/coil that I replaced by another one saved from old boards. (red circle).
(the shadow was made by my living room blinds and the bright sun shining on them). Next photo shows another view of the area where the bad fuse/coil was located.
It looks like its becoming my trademark, but again I have to conclude that the repair ‘luckily’ did cost close to nothing and was caused by only one small bad components with erratic behavior.
So if you ever have a problem like the one described, check the fuse/coils on the voltage Input lines. And look for possible signs of cracks on those components.
And the last photos show the repaired working Dreambox 800 HD PVR that will be used for tv-recording again on its internal 2.5 inch hdd. So don’t throw away your dead Dreambox before you’ve tested every part that conducts the input voltage!
Albert van Bemmelen, Weert, The Netherlands.
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Note: You can read his previous repair article in the below link:
https://jestineyong.com/exachron-dcf77-time-pulse-receiver-repair/
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Charlie Duncan
March 7, 2017 at 8:52 am
I like the trick of just pressing on the board and individual components.
Good job.
Albert van Bemmelen
March 7, 2017 at 4:50 pm
Thank you Charlie. We not always need a Digital meter to find the cause.
The problem often can be found by using our hands (if a chip gets too hot),
or our eyes (if parts are burnt, broken or missing), and our ears (if something oscillates or if a SMPS is intermittently switching on and off
very fast to protect from over-currents or over-voltages). Especially the oscillating part helped me once to fix a problem in a computer controlled radio scanner. It turned out that the squelch wasn't working why the scanner didn't produce any decent sound. A good friend gave me the scanner because he couldn't repair the problem. I found a chip that got real hot because it was oscillating at high frequencies. It was cause by a coil/transformer that was broken inside and made the chip work on much higher frequencies. After I restored the coil's internal connection, the chip was working fine and the audio output was back!
Anthony
March 7, 2017 at 8:55 am
Good work Albert......Determination and perseverance yields a reward and
the price to replace the faulty component was the icing on the cake !
Kind Regards
Anthony
Albert van Bemmelen
March 7, 2017 at 4:35 pm
Thanks Anthony. I was glad I was able to fix my Satellite reciever in no-time. And some cake with or without icing is always appreciated with coffee!
Parasuraman S
March 7, 2017 at 2:31 pm
What made you press the PCB hard? That is the intuition you developed by your ardent and sincere approach towards your work! Many miss this, when they aim only at making some more money, instead of enjoying the work being done and accept money as a resultant product! Hat's off!
Albert van Bemmelen
March 7, 2017 at 4:29 pm
I started pressing the PCB (not really hard though) Parasuraman, after
I noticed it started working when I held it in a slightly other position. In this case it therefore just had to be a bad conducting component or a loose copper track. Anyhow it is always about making some money or in this case about saving some.
George Greenfield
March 7, 2017 at 9:10 pm
Yes the "Human Touch" can be a wonderful troubleshooting tool. I have also located many faulty connections / components by applying the magic touch.
Great repair another component saved from the trash heap!
Good Job !
Albert van Bemmelen
March 8, 2017 at 3:31 pm
Thank you George. I like your approach. Of course components are getting smaller and smaller. We soon will come to a time that we need a robot to replace our hands. No doubt a result of very small components assembled by robots in the first place. We see the same thing is happening in surgery. And Nano bots are being developed to cure deadly diseases already. We have to look forward in expectation without forgetting the past.
asim
March 8, 2017 at 12:52 am
thanks for sharing
Albert van Bemmelen
March 8, 2017 at 3:34 pm
Thank you Asim. Glad you liked it. Hope it helps you to save your device when it stops working too!
Lad
March 9, 2017 at 1:36 am
Albert,
Thank you for sharing your repair.
You can find a very good source of Dreambox hardware repairs at http://jb8a8f8.com/support/index.php
The owner of that side called Johnny is from The Netherlands too. Do you know him? He is very polite and helful too.
Albert van Bemmelen
March 9, 2017 at 11:30 am
Thank you very much for that information Lad! I am not sure if I ever visited that site while searching for repair schematics of Dreambox recievers. They are very hard to find! I certainly will visit his Forum if I not already had. Very interesting if schematics and repair guides can be found there! I own 3 Dreamboxes, which now all work, but you never know when they stop working like in this repair. (;)
Robert Calk
March 13, 2017 at 4:25 am
Nice job, Albert. Thanks.
Humberto
March 13, 2017 at 11:37 pm
Hi Albert, you were patient till you found the culprit.
Yogesh Panchal
March 15, 2017 at 12:44 am
Good Job! Albert
iman
September 4, 2023 at 11:57 pm
Hello, I have a Dermbox 800 receiver, cpu it gets hot and does not turn on