T5 Capacitor problem or tuner is gone need help please

[bbatur]

My T5 worked very good couple years but when my cooling fan died over heated couple months ago, I did replace the cooling fan which is a labtop cooler not a big deal, It started working again okay, but recently I can only watch tv maybe 30 seconds starts loosing signal from 90 to 80 than 70 55 and so on at the end all red, if I cool it off it runs again 30 second and same.I checked the module its not that because same without the module runs 30 seconds at the end all red new lnb, direct input, eliminated switch.I tooked a part main board looks good no burns even replaced power supply still same factory reset everything I done you name it.Only thing I can think of is the capacitor serving the tuner and for signal strenght but don't know which one would that be I'm not good at checking electronic If any body has a good guess which one would be please let me know.

Btw if I put the board in freezer couple hours It runs longer till something gets hot I think one of the capacitor, unit changes channels display is okay.

Power on off makes it good 30 second again don't have the diagram don't know which one to change they all look good no bumps.

Thanks for the help

[Terryl]

The electrolytic caps that may be going bad are sometimes hard to spot, they only may show a small buldge at the top, some may have a discolored look to them.

You say you changed the power supply, is it a separate plug into the wall type?? (wall wart as it's called) If so the this should have fixed the problems, one question, how many LNB's are you running on your system? If more then two then there could be a problem with the DC voltage regulator for the LNB power.

Here is a photo of good vs bad caps to help you out.

Bad vs good caps.jpg

It could also be water in a connector somewhere, or a corroded connection.

[bbatur]

Thanks Terrly
I'm just running one Lnb only to find the problem as I said did everything including power supply wall wart type 3A. My other T5 runs fine with the same test.Only I don't know which capacitor to change they all look okay I'm aiming to change the 3 of them close to the tuner and module area I wish I knew which does what on T5. My conclusion is one of the capacitor is weak even it looks good it is okay for 30 second after can not handle the load to create power to even one lnb and discharges and doesn't charge back thats why signal drops to 5 and completely red till cools off power off and on brings it back for another 30 or 40 seconds.

[Terryl]

The electrolytic caps do not charge and discharge as you think, all they do is smooth out the DC voltage.

It very well could be the DC voltage switching regulator that supplies the voltage to the LNB, this regulator switches between +14 and +18 volts DC depending on the type of LNB installed and the transponder selected.

This can be measured at the LNB input connector with a DC volt meter, if you select a L or H transponder then shut the receiver off and disconnect the coax then connect a volt meter to the LNB input and switch the receiver on, you should see + 18 volts DC. (+ or - .5 volts)

If there is any voltage other then +18 VDC then the receivers LNB power supply is FUBAR and you need a new receiver.

[bbatur]

Hi Terrly checked the voltage where the coax enters 18.3V. Open the side panels of the tuner or voltage regulator what ever it's called.
When I ran the receiver after 40 second signal drops and no signal all red as soon as I spray with air duster to the tuner signal comes back and goes out when gets hot only the tuner. I thing time to get a new receiver.
Thanks

[wedalan]

If you have another receiver use it to prove the sat cable/lnb is good or bad. If that checks ok,

Your problem seems to like a cold solder connection problem within the sat rec.

If I was you I’d open it up and while plugged in and connected up press on components inside with a non conductive tool ie popsicle stick. And see if you can locate the source of voltage dropout. Be methodical and if located fix repair or replace as Necessary.

People will help if you post your findings with detailed info.

Best of luck.

[Terryl]

It could be a bad tuner, is it a plug in type? If so then a new one may be necessary.

If you have a small fan (like from a PC) you could try that to keep it cool.

And you spraying it with just the air from the duster, or with the mist that comes out of it if held wrong?

A note to Wedalan:
Good information but most of the components in these receivers are IR soldered to the PCB and would not take too well to the use of a real soldering iron.

To Bbatur, if you do not have the skills needed to re-do a solder paste type of connection then don't try it.

[Terryl]

Bbatur, re-do the voltage test but switch the volt meter to the AC mode, then post the findings here, this will tell if the DC voltage has too much AC ripple on it, that could affect a lot of things in the LNB.

Note: This test should be done under a true load, but there is no way to do this test without some very special test equipment, but a stand alone measurement will do for now.

[bbatur]

Did the ac voltage test reads 0 V. Took the board out powered up checked all solder connections tap on it nothing changes the red signal.Testing with new lnb for one satt no switch direct input.When it starts signal is 90 blue bars after 30 seconds starts dropping and finally all red no signal.When turn it on and off still red signal after couple tries and cools off cycle starts again.
I try same set up with my other t5 no problem.
Terrly you say capacitor won't do signal lost what else or should I buy a new receiver I think enough trouble shooting, I'm a Ref/AC tech electronic is not I deal on a big AC systems I change the board.
Thanks for all the help

[dishuser]

I would say you need a new module

[bbatur]

It does the same without the module on bev sd, I don't need a module for sd am I right for hd I need the module correct me If I'm wrong

[Terryl]

If it does it with or without the module, and it works fine with a second receive, then it looks like a new receiver would be the best fix.

[wedalan]

Last ditch effort,

A while back my plumber had a board with similar problems in a smart tv with the hdmi port, and after searching YouTube he found a fix for it by taking the board out and reflowing it. This was accomplished by preheating the oven and then setting the board on a piece of cardboard in the oven for about 10 mins at 395f and then just opening the door and let it cool off without touching any thing. All of the solder was like water and connections were re soldered. Do not try to move anything until it has completely cooled off. Like 30+ earth minutes!
As luck would have it problem solved. Hdmi 3 now works.

Best of luck

[bbatur]

One more question about the hd module, T5 should lock into signal without the hd module mounted to the unit on sd transponders like bev 91.Am i correct or I still need the module.

If I do maybe hd board is gone completely also, when I got the T5 hd board was installed allready.(Didn't come with original manufacturer board)
All I like to know am I supposed to see blue locked signal on sd transponders on 91 when I pull the board out.Got confused on this part.

Thanks

[Terryl]

Good question, maybe someone that knows this unit can answer better then I can.

But I think that there may be a menu setting to enable the add on tuner, I may be wrong in that, but without the add on tuner the unit should work for any standard QPSK transponder, or on any FTA satellite if you have a linear LNB, but this would require you to remove the current LNB(s) for the Dish or Bell satellites and install the new one. Also you would have to move the dish to a linear bird.

If you look at TP 12559L on 91W you should be able to pick up the free info channel,(QPSK and in the clear) this would tell you if the receiver is working or not. (I would check to see if you have to turn off the add on tuner or not)