Vestel 16MB7100-4 (satellite receiver)

[tmcw]

Have this satellite receiver that won't fully boot up, when switched on, it displays "init" on the display, and stays like that indefinitely. There is a bit of a hiss from near the transformer, it seems to be coming from the side which has the diode-resistor-diode beside it, but I don't know if it's from the transformer or the diode.

I have an identical board which does work, there is no noise at all from the transformer on this one. Normal behaviour is that when switched on, the display shows "init" for maybe 15-20 seconds, then goes into standby (it's a receiver which is designed for Freesat in the Uk, and I believe this first "init" is when it looks at the relevant transponder on 28.2E, and downloads the Freesat EPG). Pressing the standby button next, brings the unit into operation in another 10-15 seconds, when channels can then be viewed.

I have done a few tests with no power to the boards and without removing components, such as tests on the diodes, caps with an ESR meter, and resistors, but I get near identical results on both working and non-working boards. Tests on the pinouts of the transformer (resistance) are near identical too.

With power applied, I only tested the DC voltage on the top (outlet?) of the two big diodes above the transformer, and get about 11.9V on both the working and non-working boards.

I'm unsure of where to go testing next. How would I go about checking the output of the transformer, for example? Or what else should I be checking out?

I've attached a couple of photos of the non-working board.

[retiredcaps]

Re: Vestel 16MB7100-4 (satellite receiver)

Maybe the firmware is corrupted? Try reflashing or clearing?

[tmcw]

Re: Vestel 16MB7100-4 (satellite receiver)

Thanks, yes, I had thought of that, and have searched, but found nothing useful about how to flash the receiver, what software to use, how to wire it up, or even firmware to do it with. I also tried contacting the supplier here, but after several e-mails, came up against a stone-wall; they want me to send the receiver to them for evaluation. It's out of warranty, and I got it cheap second-hand, price I paid was worth it for the remote for the other working receiver, that's the way I looked at it.

If I knew how to flash it, I could probably take the firmware off the working one, and transfer to the non-working one, if I knew how to do that. There are a couple of connection on the board, a 2x5 pin (possibly a JTAG) header, and another 4-pin connector. I saw 3.3V on a few of the 2x5 pin header, but wouldn't know where to go from there.

If anyone has any suggestions on how to go about JTAGGing the receiver, I'd appreciate the input.