Receiver repair possible

[jjmaster]

I have a Samsung DSR 3700 FTA receiver that has stopped responding to the remote control. First guess was that the remote went bad, so I picked up a replacement from the dealer. When the receiver still did not respond to the replacement remote, the dealer said the receiver's infra red receptor in the receiver probably went bad and it is not worth fixing. I returned the replacement remote.

Now the receiver itself seemed to work fine for the channels that were scanned in, however you can't change channels from sitting on the couch and you can't access the menu's or rescan.

Now, I know new receivers are not that expensive, but I am interested in a do it yourself fix if possible. Anyone do something like this before and can provide instructions on how to go about doing it?

First is there some way to confirm that my remote is actually good? I can't be positive that the replacement remote I got from the dealer was not bad also (It did not look new). I have a USB infra red receiver on my PC, is there some software to run that can pick up and read the codes off of the remote to verify it is transmitting?

Second, if I confirm the remote is good.. How could I confirm the infra red receptor on the receiver is the bad part? Just dissassemble and solder on a new one? How would i find the right part? Anyway to make sure i dont fry the box myself in my repair attempt? Tips to not shock myself are encouraged

Now I know a lot of you will probably say bite the bullet and get a new cheap receiver, however this is just the sort of project I would enjoy to try. If it is unfix-able then no loss but my time, however I gain the fun of experimenting.

 

[Mr Tony]

I think Radio Shack has replacement remote sensors (they use to carry a remote sensor checker too)

Some sensors are embedded in the PC board (I have an old receiver that does that) but if you can get to it, then you should be able to replace it

 

[sksatellite]

Not necessary the sensor, it could be those small resistors went bad. I am not familia the samson receiver, so you has to look it yourself.

 

[SatAdam]

Did you try some fresh batteries in the remote?

The best way to check a remote control is with a camcorder. look in the viewfinder, point the remote at the lens, press buttons.

Works good

 

[Claude Greiner]

If you want to test the remote, radio shack sells a card that will detect infared light, or if you got a video camera point the remote at it and press a few buttons since it will pick up and display infared light!

 

[WyrTwister]

I have a Samsung DSR 3700 FTA receiver that has stopped responding to the remote control. First guess was that the remote went bad, so I picked up a replacement from the dealer. When the receiver still did not respond to the replacement remote, the dealer said the receiver's infra red receptor in the receiver probably went bad and it is not worth fixing. I returned the replacement remote.

Now the receiver itself seemed to work fine for the channels that were scanned in, however you can't change channels from sitting on the couch and you can't access the menu's or rescan.

Now, I know new receivers are not that expensive, but I am interested in a do it yourself fix if possible. Anyone do something like this before and can provide instructions on how to go about doing it?

First is there some way to confirm that my remote is actually good? I can't be positive that the replacement remote I got from the dealer was not bad also (It did not look new). I have a USB infra red receiver on my PC, is there some software to run that can pick up and read the codes off of the remote to verify it is transmitting?

Second, if I confirm the remote is good.. How could I confirm the infra red receptor on the receiver is the bad part? Just dissassemble and solder on a new one? How would i find the right part? Anyway to make sure i dont fry the box myself in my repair attempt? Tips to not shock myself are encouraged

Now I know a lot of you will probably say bite the bullet and get a new cheap receiver, however this is just the sort of project I would enjoy to try. If it is unfix-able then no loss but my time, however I gain the fun of experimenting.

I have a DSR 2700 that I need a remote for . Would you please ask your dealer if he can order one and the price .

Thank you ,
Wyr

 

[123tim]

Did you try some fresh batteries in the remote?

The best way to check a remote control is with a camcorder. look in the viewfinder, point the remote at the lens, press buttons.

Works good

Good idea! A lot of digital cameras (without an internal I.R. filter) will work too. Just watch the remote through the LCD display.

 

[jjmaster]

What exactly do you see when you point an infra-red remote at a camcorder or digital camera and push the buttons?

Are we talking Darth Vader light saber beams coming from the remote when you are looking through the viewfinder?

Or I will see laser pointer light?

 

[SatAdam]

it looks like it is a std LED light.

like you have a dim penlight in your hand.

 

[gpslobo]

Test with a remote for a device you know is working and you will see what to expect from the questionable remote... You will probably see fast flashes of light, however the flashes may be too fast to distinguish.

 

[jjmaster]

I viewed the remote via my digital camera and the LED display's a white light when the buttons are pressed.

Tested multiple remotes including the samsung. White light displayed for all.

So I assume the remote is good and the receiver is not working. The fact that a replacement remote did not work with the receiver confirms that the remote is probably good and the receiver is the problem.

Now to the next phase...dissassemble the receiver.

Ok.

I connected the receiver up. It tunes in some IA5 channels from the last scan months ago. Some channels have changed since then. I can change channels up and down and volume up and down with the buttons on the receiver. That is about it.

I can't get to the menu, do a scan or anything else.

Whip out the screwdriver and begin!

Pictures to be posted!

 

[jjmaster]

Pictures of receiver

Ok, I have taken apart the receiver and taken pics.

Now what next?

I connected the receiver to cable and turned on. Still works, but not picking up remote signals.

 

[Mr Tony]

in the last picture, the thing next to the LED dispay (to the right) looks like the remote sensor.

 

[dish_in_the_sky]

Remote sensor

I agree with Iceberg, the remote sensor is next to the LED display.

In the last pic, I think I see an electrolytic capacitor with a bulged top next to the remote sensor. If I'm correct, replace that part too, with the same value and same or higher voltage. You'll need to match the size (or close) to fit behind the front panel.

Try replacing that capacitor first. Many a problem has been caused by dried out/leaky electrolytic caps.

 

[jjmaster]

I looked at radioshack.com for some parts.

They have an infrared detector, but the dimensions do not exactly look the same as the one on my receiver. And how do I know if they are electrically compatible? I cannot see any markings or part#'s on the infrared sensor.

Here is the link to the radioshack part: http://www.radioshack.com/product/index.jsp?productId=2049727&cp=2032058&f=Taxonomy%2FRSK%2F2032058&categoryId=2032058&kwCatId=2032058&kw=infrared&parentPage=search

There are markings on the capacitor that is next to the infrared sensor.

They are: 47uF 16v 85C
I don't see a capacitor with those specs at radioshack.

Anyone have suggestions on where to find this part?

Also, do you need a special wattage of soldering iron as to not fry the board?

As an alternate solution, is it possible to replace that entire front circuit board with the sensor on it? I have the full part# embedded on it, but I have not been able to locate how to get the part from samsung. Suggestions anyone?

 

[hwh]

They are: 47uF 16v 85C I don't see a capacitor with those specs at radioshack.

Try all electronics http://www.allelectronics.com/matrix/Radial_Electrolytic_Cap.html

You can ignore the 85C temp rating.

 

[dish_in_the_sky]

Parts, soldering iron, etc.

I've had 6 years experience repairing consumer electronics, and 12 years in RF design/troubleshooting. Here are my recommendations:

N.B. Only go as far as you need to in order to fix the problem. It's too easy to break something else if you continue further. If part of this is beyond your equipment or abilities, stop there and get help. Better to do that than to do more damage. USE CAUTION AROUND THE POWER SUPPLY, THE 110VAC CAN KILL (or at least give you a nasty shock)


1. Soldering iron: Use a 30W iron from Radio Shack, just BE SURE TO CONNECT THE BARREL TO GROUND.

1A: Wear a grounded wrist strap (Radio Shack

1B: Work on a grounded antistatic mat (Radio Shack??? Digi--Key, MCM Electronics)

2. Replacement board: If the receiver is not too old (<5 yrs) AND if you can locate the manufacturer, SOMETIMES you can get a new PC board assembly. It might or might not be expensive. In any case, try. The worst answer you'll get is a $300 price or "sorry we can't sell you one," or no luck at all.

3. Ebay for a receiver of the same make and model for the right price, swap boards.

4. Be gentle when desoldering, it's easy to crack or overheat these kind of PCBs.

5. MCM Electronics, Digi-Key Electronics are two good parts sources.

6. For the module: With the receiver on, use a meter (better an oscilloscope) to look at the voltages on all of the pins. Typically one pin is the output, one is ground, and one is +5VDC. The output is usually digital, going between 0-5V typically (can go 0.8V low level to 1.6V high level as a worst case for TTL logic) with a pulse rate of 38-44 kHz (maximum, digital pulse streams are not constent frequency) as I recall. Get your ground from the satellite input connector's outer screw-on part.

Match the pinout on the old module with the new module.

If you can see the digital output (oscilloscope) check the old module when using the remote to see if its output is good (see above.)

Trace a (good) module output all of the way to the microprocessor. If it measures good on the actual microprocessor pin it's connected to, then it's probably time to replace the receiver. Otherwise find the bd resistor, capacitor, connection which is stopping it.

Troubleshooting microprocessor problems generally requires the full service manual and good manufacturer support. Even then, with good troubleshooting, with knnown good power, ground, clock and reset signals on the part, many times the microprocessor isn't bad, as proven by replacement not fixing the problem.

You can also check every pin on the microprocessor. Unless they are specifically noted to be analog inputs (such as a signal strength sensing pine) or analog outputs (such as audio,) they'll generally be 0V, 5V or a data stream swinging between 0-5V. If not, find out why and fix it.

Probing the surface mount parts (which many are these days, and most microprocessors are) is very tricky and risky. IC's especially can be damaged by shorting adjacent pins. The pins on some parts are only 0.020" apart on-centers! Get good probes and sharpen to needle points for this, brace your hands and make sure they are rock steady.