Open Box. Defective SAT - 1 Reciever!!

[scanman0]

I just snached up an "OPEN BOX" from HIFIBUYS. This unit has a faulty SAT-1 reciever. Damed if I didn't buy some junk!

Is there any way in rc.sysinit, to reverse the 2 inputs, so it "thinks" sat-2 is sat 1 ?
I see the init of the 2 logical units in rc.sysint...
Can they be reversed LOGICALLY ?

I could salvage it at that, or better yet, I'm in the market for a "bad system board-bad modem..etc.....to get the input module part, as I could change out the unit. I have soldering skills :) Anybody have a trashed board with a known good input ?


My only other option is to take the input unit from sat 2 and solder it into the sat 1 spot, and just leave sat 2 with holes in the mb..... :(

Thanks,

Scanman
:cool:

[Meathead]

Call Sony. Tell them that you just bought a "Floor Model" and that the salesperson told you that it may have some problems, but it is still under warranty. And send in your old one for a new one. I have done that a few times with Philips. The warranty period starts at the date of sale.

Meathead

[scanman0]

I can't take the unit back....

After swapping the modulator unit from sat-2 to sat 1, I was aible to get the even transponders to come in on sat-1.

This swap was a ROYAL pain in th arse....45 or so pins, and the casing for both of the units..

Now I need to trace out the voltage section of the circuit, as I have 0 volts when on even transponders. This is progress......

So this part was fried.....Now I have the voltage problem...

Does anyone have any experience with the transponder even/odd voltage circuitry ? A schematic would come in handy right about now :) I dont have time to play now, but will ring it out and source the chips used in that area. I WILL get the sat-1 working, and perhaps SAT-2, if I cant source the defective part, I'd go so far as re-design the damed circuit if needed :)

I plan on giving this unit to a guy that has a single LNB cable, in an apartment, where he's getting his sat from the second output on an LNB from his neighbor on the other side of the building, We snaked the cable thru the wall, and he's got dss, with all his outward "personal areas" facing north on his unit!

Never say you can't get sat. Just get your neighbor going (Who faces the right balcony) Hehe...

I don't give up easy ....

[scanman0]

Ok, so the rf modulator unit was fried....swapped it with modulator #2. (Needed a good de-solder sucker and a bit of patience).

Before this hack, there was 0 voltage at the LNB input when on even or odd LNB's in setup. Needless to say, I had a 0 signal strength. It was obvious that the input module was toast. The chip that supplies the LNB voltage was running VERY hot to the touch, and was seeing a shorted output as well, but the output of the rf module was NOT even supplying a signal to the input of the voltage regulator for the lnb. So this tells me that it's not just the voltage regulator. In my case the rf modulator was bad.

Let me explain a bit of my troubleshooting, to possibly help someone else who has a bad input. It can be repaired!!

Before you even start, take the cable from the dish into another unit and be CERTAIN the dish/cable/LNB are all good, don't troubleshoot the damed box, untill you have PROVEN the problem is in the box, with the aid of another tested KNOWN GOOD unit.

1. If you are getting even OR odd transponders, you have a good modulator. This is good!

(if even OR odd do work)
2. goto the "search for sat" and switch from even to odd transponders, and use a DVM on the sat input(with LNB disconnected), and see what the DC voltages are, they should "jump" from 13 vdc to 18 vdc, as you switch from even/odd transponders.

If you DO NOT get 18 volts, then 13 volts as you switch from even/odd transponders...you have a problem with your damed lnb voltage regulator. You'll see the signal strength change from 18 volts to 0, or 13 volts to 0 as the unit changes the polarization of the lnb, through this "voltage signaling"

See, the LNB decides to recive either even, or odd transponders based on the input voltage. It acts as a "switch" so to speak...

(P.S. A good cable check: switch transponders and measure the voltage at the cable right before the lnb, I had a unit once that was ran under the carpet, and the cable was pierced by a carpet tack strip, and was slightly grounded that it would allow the 18v to pass as 14 volts, and the 13 volts to pass as 6 volts, and drove me nuts.) Don't assume ther LNB is bad. It CAN be a semi-short/intermittant short in the cable too)

Ok, assuming that you don't get the proper voltage out, next step is to verify the inputs, and the outputs of the lnb voltage regulator chip.

This chip is IC "U37" for lnb #1
This chip is IC "U38" for lnb #2

ALL failures to recieve a signal will be a failure with the modulator and/or with the voltage regulator. In my case, both were trashed...

If you have 0 volts on even/odd/ or both transponders, you must troubleshoot starting HERE:

Here's the datasheet of the voltage regulator:

http://www.st.com/stonline/books/pdf/docs/5816.pdf

Troubleshoot the regulator:

You should refer to the datasheet for the pinouts, and be aware that the DATASHEET is NOT correct as it shows the oval cutout that SHOULD designate the top of the chip at the bottom of the chip, on the diagram on page 2/18 refering to our chip, the PowerSO-10 packaged "LNBP-15SP" chip. This cutout should be between pins 1 and ten, NOT between 5 & 6. I reported this typo to ST over the phone, and perhaps, it will be corrected shortly, as the tech I got on the line after 3-4 transfers was a bit embarrased about it, after he saw it :)

The Dtivo has a 24 volt source going to both U37 & U38 at both pins 1 & 2 (Vcc1 & Vcc2). This is the regulated voltage input for both the LNB's, if this is faulty, you must then repair or replace the voltage supply board.

If this is working and you have voltage into the LNBP15SP's, you then need to verify that the modulators are sending the "logic voltage" to the INPUT of the voltage regulator.

Here is how it works:

When the modulator wants a transponder that is requiring 13 volts, it sends an INPUT to the volt. reg. chip on pin #4 of 0 volts (logic low), when it wants a voltage of 18 volts, it send a 3.3 volts (logic high), IF you do NOT see this level change, as you toggle from even to odd transponders, you have a bad modulator module, as this creates the voltage for this input.

If you have the voltage changing at this input pin, then you need to also verify that you have the proper voltage going to the output of the regulator. Pin #3, and this pin is tied to the output of the modulator, at modulator pin #1, (the square pad closest to the front of the unit) You shoud see 13 & 18 Volts as you switch transponders on this pin. If NOT the VR chip needs replacing!

You can test the volt. modulator for a shorted output, by testing the voltage at pin #10 on the chip, This is a special overload indicator output, that will go to ground, ONLY if the chip detects a short in the output (pin #3), this should be open (High impedance).

[scanman0]

I unfortunatly had a bad modulator, AND a bad U37.

I was aible to get LNB #1 functioning by simply (COUGH, GAG, SPUTTER)

Removing modulator unit #2, and placing into unit #1 slot.
Removing U37
Replacing U38 into U37 position.

Now I know this is for the hardcore, Hardware fanatic, that can't allow something as simple as a few bad chips to get in the way....
I have a nice set of clean pad's waiting for a new chip & modulator, if anyone has a trashed board, with some good parts...PM me if you can be a donor.

Peace

[T_RJ]

scanman0

Nice work

I took the easy way out and convinced Philips to send me a new DtIvo.

Well the first time they sent me a SA ( blah blah bad taste in my mouth).

They appologized and I excpect to get my replacement DSR6000 on Monday.

But I might need to get down and dirty and replace some parts ( tuner ) for example and this kind of info is good stuff!

Thanks

T_RJ

[scanman0]

If this thread leaves anyone scratching thier head, it's intended for those with some SERIOUS repair & soldering experience, as well as an associates in electronics degree... at the very least.

The LNB cable test is recommended to all.

I don't want to get too deep in a message board, but I am very hardware design orientated....

[madd0c]

good to see you got the thing going...I was going to post that I was thinnking of the voltage regulator, but I decided I would be talking out of my a## and decided not to.

Anyway, so you now have sat1 input but no sat 2 correct?

I was also wondering what kind of desoldering pump do you use? I am looking to buy one and not one of the Radioshack 9.99 ones. I also don't want to spend $200.

Also, I have seen something called chipquick being used on smds...pretty slick...but would still rather have a desoldering pump.

Final question, Should I invest in a hot air gun to use with SMDs and paste? I have done all my stuff with DIPs and through hole stuff until now, but would like to "move on"...any advice?

madd0c

[scanman0]

maddoc,

I have access to a de-soldering station "pump", that will at 15 watts, suck the surface solder from a SMT chip, to the point that it falls out after I turn the board over...well (after the 20-30th time :)

It's cool to have the right tools, but in reality, a good bench weller with a slide wattage control, and a great solder sucker, ok I'll admit I didn't buy a $400 unit, I'm cheap, As I use an aquarium pump, and a very thin hose, and it creates a GREAT suction, probably better than the $400 one my last company took away from me, but I have a nice tip on it, and
If can place a pin tip iron and place it there, and "suck" even one side of a smp package, and not mess around. I have a tweaser set, and place smt stuff...I can de-solder and re-solder an smt unit, not to mention, I can make things like the modulator unit "drop free" from the pcb!

[scanman0]

As I read this, posting that I can drop free SMT components, may give people the "IDEA" that the origional hack in this thread is EASY....It is NOT, and should only be preformed by experienced soldering type people, or skilled soldering tech's....I WILL not feel sorry for the first time trash shack solderer, who proclaimes "I'm a trash shack looser, and I killed my tivo!"

Carefull soldering is a REQUIREMENT

[weazil]

Where can I find the U37 and u38 chips?

I believe mine are fried.....

[daurora]

Has anyone figured out how to do this swap in software instead of going through soldering hell?

[AlphaWolf]

Funny this thread should be brought up again, the other day I was playing with send5505 with my second tuner disconnected and somehow managed to get the message telling about it searching for satelite signal to go away. I would say exactly what I did but I forgot.

I think I was sending random hex values to see what they did.

[scanman0]

I went through ALL of ST's supplier pages, and exausted all of thier "distributors", in an effort to "BUY" this voltage supplying LNBP15ST TAC034 chip.

I eventually gave up, seeing as how the distributors laughed at me, when I wanted to order a quanity of 5.

I then called ST sales folk, and begged them for an "Engeneering sample", and provided them my corporate info, and seeing as I'm in the telco industry, they had no problem shipping me the sample chips. But in reality, it's not available, in any RETAIL form.

I have begged eeproms for motherboards in the past, the same way......Don't think you can do this without the proper lingo, and corporate type talk, as you might buy 10K of them, if your design pans out....

But the "Eng. Sample" route is the LAST RESORT, as I'd buy any chip, before I did this, and sometimes, I'm just "strait up honest", and beg, and the sales rep will send me the chip. Just don't BS, and abuse any chip rep.

You can get chips that are not avail. by the manuf. by any distributor that they have.....Explain you tried ALL distributors.

Offer the sales rep a $30 gift cert. for red lobster, he will probably just bend, and say, ohh...ok, don't bother, I'll send you a "sample"....for free!!

I've recieved sutch a social eng. type plea arrive overnight fedex.

SHOCKING, but possible...Don't abuse this social eng. request, and HONESTY will get you further than saying, I'm a buyer, and I (might) need 30K pieces, and ship me a sample now!

They KNOW thier buyers, and you will fail.

But, if you catch the chip rep. in a good mood, he can shoot you an eng. sample of any chip, with a few clicks.

Play nice, and you too can get free chips :)

[scanman0]

Even IF you do get this chip from ST, you will be fighting a MAJOR battle, as it's easy enough to solder suck the pins' and lift them, BUT the package of the unit is SOLDERED to ground, with a good 1 cm square package to the PCB. I was cussing at it, AFTER lifting all the pins, with the packaging removal. I have a Weller soldering iron station, and I cranked the unit up to the max heat (450 degrees c.) and held it on the packaging, (Solid mouting square heatsink) and it took a SERIOUS 40 seconds before my dental pick was aible to leverage this chip....It's a major lift, you can't do it with a trash shack iron, except the 80's gun with the light bulb (hehe)

You cannot remove this chip from the PCB without a SERIOUS high wattage iron, and a low wattage iron for the pins. It's a project that is on a scale of 10 out of 10. I cussed at it!

I replaced SAT2 chip on SAT1 spot, before I recieved the replacement, and nearly bent the pins to snap point, but even carefull, lift, solder suck, and place.....I lifted a pad, (sorta), and it was not ruined, but it's hard soldering..

[PeterGriffin]

I have two dsr704's. The sat1 chip and/or tuner doesn't work in either one of them. My question is, can I take the sat2 chip/tuner from one of the units and put it in the sat1 slot on the other unit and be able to use both tuners on that unit? Thanks in advance.

[earnric]

PG,

I don't know about that, but i have a Philips 708 that 'occassionally' drops signal on one of the tuners. Is this the behavior you are seeing?

Every week or two, my second tuner drops signal: if you look at the signal strength screen on the Tivo the signal drops to 0 for about 1/10 of a sec... every few seconds. This behavior lasts for a day or so, then it goes back to normal.

The signal dropouts manifest as video/audio problems with the recorded shows.

Some of the PTV guys think this MAY be a hard drive problem... I'm curious what your tuner problem "looks" like.