Topic: General Frag (Read 69 times)

AfterTheInsanity · « **on:** October 04, 2007, 09:20:00 AM »

LPC looks fine, I filled all the vias with fresh solder to make sure there arent any broken via-connecting-tube-things. No cut traces or torn vias but the LClk and Rst voltages are a bit low (0v and 0.19v, should be 0.2v and 3.3v respectively). Dont have a modchip to test with, but Ill toss in a 29-wire mod when I get home to check. Anything I should be looking for?

AfterTheInsanity · « **Reply #1 on:** October 04, 2007, 04:29:00 PM »

Frag's with a 29-wire mod, so its got me thinking it's hardware. Any definitive continuity diagrams for all 15 LPC pins? Im thinking the problem is there, as thats the only thing I touched.

AfterTheInsanity · « **Reply #2 on:** October 12, 2007, 01:38:00 PM »

Bump!

AfterTheInsanity · « **Reply #3 on:** October 12, 2007, 08:39:00 PM »

Put in a Xenium Gold tonight. On the first try in recovery mode, it gave me a garbled screen (but it did boot!). So I turned it off and turned it back on and it just went back to frag'ing.

With the chip in recovery, it frags within 1/2 of a second of turning it on. With the chip in normal mode, it frags within about 1.5-2 seconds of turning it on. Only sign of life left in this thing. Someone must know something, or have tips... Anyone have nB's email?

AfterTheInsanity · « **Reply #4 on:** October 12, 2007, 09:25:00 PM »

After leaving it plugged in for about an hour, in recovery mode, the console stays on, but using the RF adapter, Im left with a black screen, which sometimes flashes some pretty funky colours (im guessing its trying to show the menu, but I dont have an a/v cable to rule out my RF cable). When I power up, the LED goes red -> amber -> red -> quick flash of blue -> off, until I press the power button, when the front panel LEDs turn off for about five seconds, then the Xenium LED goes red for a split second and turns off. Kinda getting somewhere...

EDIT Oooh, after many tries Im finally getting a barely-readable menu.

Bomb Bloke · « **Reply #5 on:** October 13, 2007, 08:27:00 AM »

Probably nothing here you don't already know, but for what it's worth...

Electronic gear is affected by temperature. Usually this doesn't make much difference (you might notice your DVD drive tends to stick in certain weather conditions), but when a circuit is faulty it becomes quite noticeable.

Somewhere on your board is a loose connection. When you power up the box the sudden surge of current is enough to spark across the gap (meaning the box turns on), but that soon subsides to a normal level and the box crashes.

If you leave the console powered on long enough, the components change shape slightly as they warm. Often this bridges gaps and it might even be enough to make a box boot. You might have heard of the "freeze a broken HDD" trick, it's the same sort of concept.

The question in your case is where the loose connection is. Doesn't look like anyone recognises the symptoms as something specific, and I'm no exception...

Official docs say FRAG is an EEPROM issue, though if memory serves my boxes also do it if I unplug their drives (though they still go through the flubber sequence).

RAM problems usually lead to a triple-boot-then-FRAO, so they're probably fine.

My bet is with one of the processors.

All I can recommend is applying pressure to the various chips inside the box and booting the console up. Keep trying different ones until you get a proper boot, and just hope that the one at fault has easily accessible solder joins. If you're really lucky you'll be able to spot a small burn mark somewhere, that'd save you some time.

AfterTheInsanity · « **Reply #6 on:** October 13, 2007, 01:49:00 PM »

FINALLY! Someone replied! Thankyou

Ive scoured the board looking for ANYTHING that could tell me whats wrong, but I didnt come up with anything. Something tells me it has to do with the video encoder or MCPX, since the video output is kinda... well, screwy. Im trying to find someone with a heatgun so I can reflow the solder around the Conexant encoder, but if that doesnt do it, I might end up baking the board in an oven to try and reflow the solder under the MCPX, GPU, and CPU. Anyone have any tips for this - temperature, time, etc?

networkBoy · « **Reply #7 on:** October 13, 2007, 09:01:00 PM »

You answered your problem already.
The reset line has got issues.
Reset (RST) is active low, that is when that line goes low then the chips connected reset.
Looks like you may have a damaged trace and/or a bad chip somewhere. Try to follow the traces to/from the RST point on the LPC and look for any damage, use a DMM to check anywhere where it goes to a chip or via for voltage. If one chip has 3.3v and another does not there is likely trace damage. It could also be that the PIC or MCPx are holding the line low (or a broken ball under the MCPx, though not likely).
Lift the RST pin on the PIC (carefully) and see if that helps, if it does it's time to pull the chip off anf buy a new one. Finally if this is a 1.0 board, then the borked MCPx is more plausible. I'm not sure what they did, but the reliability of those things was not good on 1.0's but was better on later versions.

HTH,
-nB

AfterTheInsanity · « **Reply #8 on:** October 13, 2007, 09:31:00 PM »

New symptoms to add to the list. Er. Symptom. It says running for about ~6 seconds, just enough to say "loading xenium os" in a psychedelic way, then shuts off. Turning it back on keeps it on for a second and it shuts off. After a few tries it doesnt even turn on anymore. Have to un-plug it and leave it for a few hours to get it to try again.

Bah.

EDIT Uhoh, as its turning off I can hear that crackling sound that almost always comes from something shorting. Time to put it back under the magnifying glass.

AfterTheInsanity · « **Reply #9 on:** October 14, 2007, 09:45:00 AM »

Which pin on the PIC is the RST pin? I did a continuity test and none of them came up with 0 ohms. Tried following the trace back and it lead me close the the PIC, then right past it.

networkBoy · « **Reply #10 on:** October 14, 2007, 11:34:00 PM »

Pin 1 (VPP and Mclear#)
-nB

http://ww1.microchip...eDoc/30605c.pdf

AfterTheInsanity · « **Reply #11 on:** October 15, 2007, 02:09:00 PM »

With Pin 1 lifted, the Xbox does nothing. Wont respond to the power button. With the pin reconnected, it goes back to its fragging w/o the modchip, and wierd colours w/ the modchip.

EDIT after leaving it plugged in, its acting kind of ghostly. Turns on and off at random, for anywhere between one and five seconds, until I unplug it. None of them lead to a screen with good visuals.

Bomb Bloke · « **Reply #12 on:** October 15, 2007, 04:58:00 PM »

Perhaps if you showed some screenshots as to what comes up on your TV?

Might not help at all but I for one would like to see them.

AfterTheInsanity · « **Reply #13 on:** October 15, 2007, 05:38:00 PM »

Well... I found out where it was shorting... The TSOP just caught on fire!

Hope I can remove it and salvage the board.

Never knew TSOP's burnt white.

Bomb Bloke · « **Reply #14 on:** October 15, 2007, 05:50:00 PM »

I wanna see a picture of that, too...

It's odd, though. I thought a modchip would've by-passed the TSOP and hence the problem. Well, unless the short wasn't directly under the original, I suppose.

Author Topic: General Frag (Read 69 times)