How to NOT glitch loop your cams

[DrSagan]

Many of us have pondered for a long time whether these cards are physically damaged during the glitch attack and not software looped. In my opinion, this answers that question.

Last week Reb and I were discussing the things that "could" be happening and I mentioned some things that I saw the last time I used the DSOscope and we both agreed the voltage spike I remember seeing when the "gate" closed couldn't be a good thing, so we set out to see if we could "clamp" the voltage.
First, here are some results from testing. 4053's would produce a semi-square waveform ~6v peak to peak voltage swing while 4619's would produce a much nicer square type waveform but would "ring" terribly upon it's return to 5v, producing over 8v peak to peak swing at times. I have to believe some glitchers are even worse.

Bottom line, after much testing of different diodes, we ended up using a 5817 fast switching Schottky diode and achieved almost the same square waveform but with a peak to peak of only ~5.4v. We tested this mod on all revs of cams and it didn't seem to hinder unlocking at all. Time to do the real test, I ran a cam for over 15 hrs straight with the most agressive nastiest attack I have and it wouldn't die(this is not a script to unlock). I removed the diode and killed it in less than 5 seconds.

Now it's your turn to test the mod out and see if it doesn't stop 90+ % of the looping due to "noisy" waveform.

The mod is simple, 5817 Schottky diode. Annode to cardslot vcc, cathode(the end of the diode with a band around it) to +5v side of the voltage regulator. For those that don't know what a diode does, think of it as a one-way gate with free flow one direction and 1000:1 resistance the other direction. The flow goes from annode to cathode. When the voltage is too high it flows through the diode and the regulator always trying to maintain 5v will "absorb" the excess. The importance of the fast switching Schottky comes into play when the "glitch" tries to reduce the voltage, we need that diode gate to close rapidly or it will let 5v through from the regulator and affect our waveform.

I'm sure there are a few cards around that are software looped (like rom103's that people used rom102 scripts on :rolleyes: ) but I bet the majority have some sort of hardware "anti-glitch death fuse" that is blown.

Attached are pictures of the cardslot pinouts and a modded t911 with the diode attached to give you an idea of how simple and cheap this is to do. I haven't seen Schottkys at rat shak, but any reputable electronics house will have them and I'm sure they're on ebay too.

I guess I can't attach pics. Maybe a mod can add the pics.
hxxp://download.yousendit.com/94D47BA91A574AF9

[DrSagan]

I should also state that this is no guarantee that you won't kill cams, just a quick easy mod that will probably prevent 90% of the glitch kills. :)

[Electric_Menace]

I assume this mod could be done on any unlocker like the white nexus???

[s_gm06]

kool ill try it tomorrow

[JT]

Great post Dr. Sagan. Over most of our heads, but a great post.

[s_gm06]

maxim -c you can get 2 samples from them

[s_gm06]

o yeah thanks DrSagan tried it and i see that its alot harder to loop cams with than without thanks again [Do you make house calls? lol]

[Ohms]

This sounds like a real breakthrough. I wish I had it on my white nexus day before yesterday. :(

[lightning0009]

Nexus no loop diode mod.

[lauchie]

You can find these resistors on old pc boards,found a few allready.

[Electric_Menace]

Thanks DrSagan for the great info and thanks lightning0009 for the Nexus pics.

[amcanh]

Does any have instructions on how to do this with a blue nexus? I would like to try it. Thank you.

[Ohms]

amcanh.. look at the pictures and initial description above. Should be all you need.

[Crazy1_79]

excellent post, I will mod mine and see how it goes

[mackscb]

Nexus no loop diode mod.
Is this for the White Nexus?

[s_gm06]

same for all nexus just solder the diode to the 5volt side of the power regulator

[mackscb]

The pic shows 8 pads where the diode is attached on the bottom of the board. My white nexus only has 4 pads here. Do you just attach to the forth one?

[Ohms]

the picture below shows the pinouts for the cardslot connections. Go by that instead of the circuit board picture.

http://www.dssftp.com/forum/attachment.php?attachmentid=8567&d=1165351781

[amcanh]

amcanh.. look at the pictures and initial description above. Should be all you need.
Thanks Ohms and DrSagan. I am trying now to secure the diode and will try it. It really looks good. Thanks again for the help.

[mtmt1us]

will this work with mikobu n2 ?? thanks

[s_gm06]

yes

[JoeSixpack]

what voltage, amperage, etc.... can someone post the printed info off one? (should have letters and numbers printed on them.) Or post a good pic of one close-up? Thanks!

[mackscb]

the picture below shows the pinouts for the cardslot connections. Go by that instead of the circuit board picture.

http://www.dssftp.com/forum/attachment.php?attachmentid=8567&d=1165351781
Got it Ohms and much thanks to DrSagan. I ordered my diodes today. Only $0.12 ea but had to buy ten, so I have a few extras.

Now if I can just get someone to send me a rev 108 to test this on. LOL

[Ohms]

I dug out a couple of old motherboards. They had these diodes on them near the keyboard buffer and cmos area. One board had 2 on it and the other had 1.

These old board were worthless otherwise. I got no problem yanking parts from these brain doners. My wife gets on me for hanging on to this crap. :) NOW SHE SEES how I have save $0.12!!!! ;)

[vmod32]

Thanks Doc.

This is a real easy mod that everyone should do. You can do it will any loader. The dirctions are as simple as they can possibly be.

"Annode to cardslot vcc, cathode(the end of the diode with a band around it) to +5v side of the voltage regulator"

So now people can stop asking if it will work with their loader and how to do it. It works with any loader and he told you how to do the mod.

The attached pictures about tells you were the vcc on ANY card slot is. If you can't figure out where the +5 off the voltage regulator well then now is a good as time as any to figure out how to use a multimeter. You can't get too far in this hobby if you can't use a multimeter and some real basic soldering skills. This is the perfect simple mod to learn how to do both if you don't know how.

[TDC]

JoeSixPack:

5817 - Schottky Rectifier rating 20V, 1Amp

I found these at a local electronic parts supply. Came in a 5 pack - cost 99 cents.

The diodes have the number 5817 and 8449 written on them. If you are looking on an old PC board to get them off of. Look for the 5817 number on the barrel of the diode.

[JT]

And don't forget, diodes have polarity. The black line on the diode goes on the regulator side. (most diodes are red with a black line, but the line of color that doesn't match most of the diode is what goes on the regulator side)

[JoeSixpack]

Thanks guys!!!

[s_gm06]

ummmmmmmm i think thispost is done as it is easy as pissin lol

[jskey]

Might be worth being a sticky if it proves to save some roms. Unfortunately wife dropped my modded t911 and haven't gotten it to work since. Maybe Ill
try repairing it someday,,,havent had any luck so far,,,,,tried

starting over with the mod

cleaning the board to make sure there was no floating slag

when I flash the atmel, it says flash taken, but when I try to run
the software says I need to flash, so Im at loss,,,,but

nice mod,,,,,definitely worth passing the word around

[Ohms]

jskey. Try it on another pc and see if you get the same result.

[TDC]

I did this mod as posted on Nexus with the 4619 chips. Odd thing, with the diode in place, can't get ATR or anything from the card, any card. This is using NagraMaster or/or WinExplorer with the right script. Remove the diode and eveything is fine. I checked the polarity and placement of the diode and everything is as documented. Even checked the diode (and replaced it with a new one), same thing happens.

Am I doing something wrong? Anyone else experience this?

[s_gm06]

make sure your putting it on the io on the card slot pin 2

[TDC]

I put the diode on as per the instruction & pics posted above - card slot vcc pin has the anode and the cathode (banded side) on the +5 VDC leg of the regulator.

Is this correct?

[Texas Trophy]

Post a pic of yours if you can.

[s_gm06]

i had a bit of trouble with the diode make sure it is correct type 5817 fast switching Schottky diode jskey minedone that when the diode was on the wrong side of my regulator

[TDC]

Guys Thanks for the help.

Looks like image uploading is broken. I'll upload the pics of my unit as soon as possible.

[s_gm06]

what voltage is your power supply at 9 12 or what i find my card gets no atr at 7 volts or lower try 12

[TDC]

I'm using a 9 VDC, 500 ma power supply. I'll try your suggestion and let you know what happens.

[mackscb]

I did a separate post on this problem as I was not sure the mod had anything to do with it, but now I do, so I will post it here.

When I did the mod on my white nexus, I also replaced the cheapo pot with a 5K multi-turn pot. While I was checking the connections, I noticed that I got a different resistance reading depending on which lead from the multimeter was connected to which contact.

I disconnected the diode tonight and measured the resistance with the meter leads hooked up both ways. I get the same resistance either way (3.75Kohms). When I reconnected the diode, I get 3.5Kohms or 2.35Kohms depending on how the leads are connected. The diode is definitely causing this.

Can some of you guys check your unlockers and see if you get the same result?

[s_gm06]

why is your ohms set so high ???? But my orange nexus doesn't seem to have that probelm must be where it has 4053 chips

[mackscb]

why is your ohms set so high ???? But my orange nexus doesn't seem to have that probelm must be where it has 4053 chips
It's just where I had it last when checking it. The difference is a higher percentage at the higher ohm settings.

Pics of my connection can be seen here: http://profile.imageshack.us/user/mackscb/

[mackscb]

Tried to edit the live link above, but it wouldn't let me. Sorry if that is a problem.

[s_gm06]

with the 5817 fast switching Schottky diode at a higher voltage mine kinks out completely works best at 9.5 volts on my orange connections look perfect in your pics what kind of computer are you using and what are the port settings?

[mackscb]

I haven't used it since the mod. I am trying to confirm whether this is a problem or not before using it again.

[s_gm06]

ok ive got a budd who has same loader and his does it to but it doesnt hinder the unlocking at all but he hasnt looped a cam since so its all good to go before though he looped 3 103's and my 102

[mackscb]

Alright. Thanks. It's good to know I'm not the only one with this result. By the way, which resistance reading would be considered correct?

[mustwatchtv]

mackscb, this is the mod I was looking for, for a long time!!!. I did the mod and I popped a 10B in 10 seconds, yesterday I looped 5 in a row without the mod.
pot was at .220 under 2k settings and I didn't change anything on the script also 9v 300Ma


awsome bro thanks

[mackscb]

Hey, don't thank me, thank DrSagan. He's the wizard that came up with this. I put it on a Vortex also and haven't looped one since.

[mustwatchtv]

thank you "DrSagan" without people like you this hobby just wouldn't be the same . I did loop another 10B but I surely can tell it takes alot more to loop them now.


thanks again bro

[PizzaBoy]

Hi Gang

Not sure whats wrong, not a single image in this thread will load for me.

Anyone mind telling me what pin is the VCC?

I know its a simple mod.. ya just have to follow the pictures and you cant go wrong.. right!

Cheers
Pb