Schematic For Echostar AD3000ip Power Supply

[reginald]

Hi Llew
The receiver would start up alright for about a minute then the psu would reset and then start to cycle at 2 second intervals. The 8V line was suppyling 18V which was causing the 5v reg on the main board to overheat. As only the 5V is regulated which feeds back to the primary then I guessed that must be to do with that. After studying your excellent schematic I opted for C16 the 5v smoothing capacitor. Swapped this and voltages have gone back to normal. I think that it was causing a ripple ie 5V then 0V then back and the primary side was boosting as the 5V dropped to zero volts down the half wave. I think I will swap a few more while I am it some look very tired. I think the overvoltage might have stressed them. R17 as cooked due to the 60V it had across it. Many thanks for a great schematic.

 

[Llew]

Good to hear you found the culprit. Yes, it can be misleading checking with a meter - a 'scope would have noticed that ripple.

As usual, electrolytics are the main cause of breakdown in hard-working SMPS.

Llew

 

[zerok]

Although not to be the model of my receiver, congratulation for the wonderful and great work Llew. On the other hand, I would like to know who have an Electronic schematic of Positioner with command the DiSEqC 1.0/Usals?. Or any other model to serve as reference.

Any help would be appreciated,
Zerok
[/email]

P.S.
I have a motosat DiSEqC 1.2 Made by DHAM ENG. It is with problems.

 

[Llew]

You mean a v-box? Don't know of anything for these myself.

BTW it's advisable not to post your email address (attracts spam).

Thanks for your comment re the schematic

Llew

 

[madeira1]

Ref AD3000IP
Llew could you please confirm values of Resistor - R3 and R17.

Thanks

Jana

 

[Llew]

R3 15K 2W (the power rating is a guess - I compared it for size with known rating values of similar resistors - use the largest that can be accommodated on the board).

R17 1K 1/8W

For a full component list see -

http://www.satellites.co.uk/satelli...29-component-list-echostar-ad3000ip-smps.html

Llew

 

[madeira1]

Thnaks for your help.

 

[vlammie]

Hi Llew

Thanks for your work on the schematic diagrams of the SMPS. I had recently updated my receiver with new software etc. and had it work again perfect for me. Until a tikking sound came out of the receiver. It turned out that the R3 had "soldered itself out of the Printed Wiring Board". I was able to find things fast with your diagrams. Thanks again and hope I can use it again for a long period. AD-3000ip is a wonderfull receiver.

Thanks again.

Vlammie from Holland

 

[Llew]

Hi vlammie, welcome to the forum. Glad you found it useful. Yes, R3 is the main suspect in the supply after the electrolytics. My receiver is still in service regularly for driving my dish.

Llew

 

[pcsel]

I have an AD 3000IPVIA which I have had for years which has just lost the Horizontal channels, Checked the 13/18v switch and 18v isn't there, where's the pick off from the PSU for this please? Anyone seen this before on these models

Many Thanks in Advance

Paul

 

[Llew]

Hi, It's fed from the 21V line out of the PSU. I had to replace the switch some time back, and from the notes I made, the 21V goes to the +12V regulator U901 which feeds the emitter of the switch (Q903).

If no switching occurs, there will be a standing ~12V on the collector of Q903, which is enough to power the vertical polarity of the LNB. Switching is derived from the PowerPC controller chip via Q904.

Not sure how the horizontal voltage is derived from this circuit when switched, I'll check my STB when I have time; meanwhile if you could supply some voltage readings of the transistors concerned I could compare with mine.

Llew

 

[vlammie]

Hi Llew

My ad-3000ip has given up again recently. Again ticking sounds came out of the cabinet (and flickering display). I have investigated the power supply separately again. Turned out that I could not switch it On and Off with PCS line. Finaly replaced Q2 for a BC237 which solved this issue. Put it back in, but the receiver still had the same problems. Tried to load the outputs of the device as it seems that the PSU is switching On and Off. If I load the 5 V output with 18 ohms resistor it is already breaking down. Anybody any idea how much current can be drawn from 5V digital. Expect that it should be much more then just 300 mA as I am trying now.

 

[scooby12]

thanks for the diags have got the r3 hotspot problem which with the help of your drawing and info i will calling in at maplins to get a replacement
so fingers crossed it will working soon


Cheers

 

[Llew]

Hi Llew

My ad-3000ip has given up again recently. Again ticking sounds came out of the cabinet (and flickering display). I have investigated the power supply separately again. Turned out that I could not switch it On and Off with PCS line. Finaly replaced Q2 for a BC237 which solved this issue. Put it back in, but the receiver still had the same problems. Tried to load the outputs of the device as it seems that the PSU is switching On and Off. If I load the 5 V output with 18 ohms resistor it is already breaking down. Anybody any idea how much current can be drawn from 5V digital. Expect that it should be much more then just 300 mA as I am trying now.

The 5VD line draws just over 500mA fully loaded. So you need a 10 ohm resistor with a rating of at least 2.5W or more.

Check that current is actually being drawn on this line - it may be the source of the problem if it's overloaded and shutting down the power supply.

Same with the 5VS line. This takes 1A. To check this, you will need a 5 ohm value resistor rated at 5W or more.

Llew

 

[vlammie]

Hi Llew

Actually it does not make any difference if I load the 5VS or 5VD line. If i attach a 18 Ohm / 10 W resistor it already goes into hick-up mode. I have swapped several components now (IC3 with IC7, IC2 with IC6) just to see if one of these is bad. Without any succes however. Also measured components in the feed-back loop, like C15. The behaviour of the SMPS is still the same. So most suspect is now IC1 (1H0565R). I have ordered 2 pieces in the US at http://www.bluestar-online.com. I will let you know if this solved my problem after they arrive. This will take a couple of day's i presume. So we have to keep:-thumbup

 

[Llew]

It does seem to point to a problem in the primary side - check the components ariund IC1 before replacing it; the IC has several protection circuits within (voltage, current, thermal).

Check D5/R9 which provide the main Vcc voltage after turn-on. If this is missing, it could be causing the tripping. Be careful when checking this side of the supply though!

I have a spare receiver that I use for checking queries on the SMPS, if you need any voltage comparison checks, just ask.

Llew

 

[scooby12]

quick update tried replacing r3 with the value listed 15k 2w and it didn't work lets say it had a short but brilliant life it glowed like a 40w bulb looks like a new sat on the way any ideas out there to replacements ????

 

[Llew]

So the original resistor wasn't fried, just the board burnt? If this was the case, I have to ask - what was the Maplin's code for the resistor? A quick end to your replacement suggests the wrong value was given.

As for a new STB, not much available now with a built -in positioner, most boxes now use a DiseqC controlled external unit (Vbox) for operating a 36V motor. Plenty to choose from - Technomates are a popular choice.

Llew

 

[vlammie]

Check D5/R9 which provide the main Vcc voltage after turn-on. If this is missing, it could be causing the tripping. Be careful when checking this side of the supply though!

Llew[/QUOTE]

Hi Llew

I will take care. I have been "shocked" in the past when I was young:-HoHo and also have blown up some probes already :-googly

I work now with an oscilloscoop "of ground" which is dangerous also. So don't experiment with this if you don't know what you are doing.

Thanks for your tips. I had tried these all already, but did not find any defect components in the power supply of IC1. I measure a steady voltage of 17.1 Vdc at pin 3 of IC1 after starting up. What I also see is that the SMPS has already problems starting up unloaded. It makes already a number of hicks (about 10) before it is stable. Hicks have an interval of around 100 ms.

 

[Llew]

I always use an isolation transformer with the 'scope when checking the primary side!

Have you checked all the secondary outputs for shorted diodes (D8,9,10) and their smoothing electrolytics for shorts? Maybe one of them is damping the windings of the transformer and preventing IC1 from powering up.

Llew