Could you possibly using too much memory. What do you use your Jtag for ? Just MW2 ? If so, try a different patch ?

I'm just shooting ideas here so, sorry if im wrong. I'm just trying to help.

Also check the temepature whilst running the device.

devray97 wrote go to jtag modding luck at a sticky post called jtag technical support post there you will get reply

You will get a great answer from that < 3

well my jtag never had this problem but my old xbox had the same problem it would start up and when u start a game it would freeze or u sit to long it will freeze then a week later i cut the xbox on and i got black screen with small white dot so i cut it off and on again then i got everybody favorite lights rrod hope this doesn't happen to you

needs rflowing i think south brodge question asnwerd

It's because it's overheating.
It doesnt matter what it feels like on the outside, it matters how hot it is in the inside.

Beekin wrote It's because it's overheating.
It doesnt matter what it feels like on the outside, it matters how hot it is in the inside.

Ok but I havent used it enough that it should be overheating. Total i have used it for about 8 hours. And it wasnt used when i got it

TurkishDelight wrote My jtag runs for a little bit then just freezes up. Im not getting red rings or any thing it just freezes.

I will give you +Rep

go to radio shack buy thermal paste take the gpu and cpu heat sinks off remove the access thermal compound heat up the gpu and cpu let cool for 10 to 20 mins then add thermal compound evenly on the chrome part of the gpu and cpu then instead off using xclamps use 8 screws and 16 washers also look it up on utube its a pretty basic fix.make the fans 12v and add extra fans +rep if helped

your gpu is overheating u will get 3 rrod error code 1101 unlesss u take out dvd drive and install a 12 fan directly on the heat sync and correctly x clamp fix it i have done this now to 4 boxes thaht had the same problem all of them work now and ive had no problems since
you will need some thermal paste aswell

cheers man

Sounds like overheating... You need a beter method of removing heat from your consle.

Sorry to grave dig, but I am running into this scenario. I have tried booting without drives, and have replaced the thermal compound with artic silver 5. Fan speed is set to 100%. Last time this happened, I reflashed nand, and while I was in there updated my dash. Things ran great for about 2 weeks. Now I turned it on, played a game for about 15 minutes, and it froze. I rebooted it and played for another 15 minutes and it froze again. Rebooted, then the xbox logo would freeze during boot up. No RROD's just frozen. Rebooted, now no video or sound. Xell does not display either. I would think cpu/gpu/mem temp or connection issues would throw an error code. But no red rings. Maybe another reflash......but I just did one a few weeks ago? Any help would be great. Thanks everybody.

EDIT:
I left it for a while and was able to run it for a few minutes. According to FSD my cpu, gpu, and mem temps were all around 45C. Case temp at 23C. When I tried booting without any drives - it went to M$ Dash (13599) and then went solid green on freeze. I think I might need ICY?!?