Echostar LT8700 No Picture

garga pista

garga pista

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Messages
18
My Satellite Setup
Amiko Alien SHD-8900, Amiko Ampulse WiFi, Nokia D-box
Dishes:Astra19,2-HotBird-Intelsat/Thor
My Location
Hungary
Hello!
I'm trying to repair an LT-8700 receiver, looking for a schematic or service manual, or just an advise. It works "halfway". The receiver boots up, front panel display and remote works, but no picture output. No picture, nor OSD on the TV scart, RCA plug, or on the modulator.
The receiver had D2mac and Videocrypt decoder boards, I've removed both, it works without that 2 panels, but still no picture.
But on the VCR scart i can get "sparklies", changing the channels seems working, but no OSD on the VCR scart :(
But if a connect an another receiver on the VCR scart, the receiver switches to it, on the decoder phono out comes out the picture (still without osd).
PSU works, all the voltages measured correct. Does someone has any advice? I've made some pictures from the inside, it looks interesting, that there's a vertical panel in the back with 3 connectors. From the 3 connectors, one has a lot of cables running different places in the main board. Is this normal, or is it retrofitted?

IMG_20200522_190115.jpgIMG_20200522_190122.jpgIMG_20200522_190140.jpgIMG_20200522_190148.jpg
 
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
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29,667
My Satellite Setup
A little less analogue, and a lot more crap.
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UK
You may find the fault is a switching transistor on the main board, diverting signals through the decoder boards when a particular encryption was received.

Have you tried working your way - blind - through the menus to perform a factory reset ?
 
garga pista

garga pista

Member
Messages
18
My Satellite Setup
Amiko Alien SHD-8900, Amiko Ampulse WiFi, Nokia D-box
Dishes:Astra19,2-HotBird-Intelsat/Thor
My Location
Hungary
Thanks for the reply, first i tried blind the factory reset, it did not help. Then i removed the 2 decoder boards- still nothing. I couldn't find the service manual, but looked for the chip datasheets from the main board. And bingo! The STV0030 switches between AV,decoder, etc and inserts OSD. So I traced down where the signal goes, and found a bad soldered capacitor under the vertical sound panel (someone already tried to fix it, badly soldered it) So soldering back a new capacitor properly made the receiver back in life :) Here's a picture about it. And here's the datasheet for the STV0030 chip, it could be useful for fault finding, for me this was the solution: Datasheet Archive STV0030 datasheet download
Edit: upload the datasheet here
STV0030_main_board.jpg
 

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Lazarus

Lazarus

Tout Rond Bon Oeuf
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25,851
My Satellite Setup
80cm Motorised.
Several small Dishes.
Much else.
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North York Moors
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