Advice on Chihiro Repair

[twistedsymphony]

I bought a "non-booting" Chihiro Type 3 off of YAJ. it was cheap (by Chihiro standards) so I figured it was worth the gamble.

It was missing the AVIP cable and when I first inspected it I noticed that the Memory caps were all exploded.

I replaced the caps and built a new AVIP cable, put a new coin battery in the AV board. When booting it attempts to boot twice and then FRAGs (typical main board fault on an Xbox). No video output, but I do hear the speakers "pop" on each reboot. I Also noticed a terrible sound and it seemed to have good air flow out of the main exhaust fan so I booted with the media board removed and the GPU fan has crapped out, basically grinding and spinning slow/sporadic .

My fear is maybe the GPU is cooked, though in my experience with the old Xboxes they should still run with a dead GPU fan and generally stay cool enough, so long as the exhaust fan is working well and you're not running the thing in 90deg heat. I also noticed the Aerogel cap is missing though I'm unclear if this is typical on the Chihiro or if someone removed it at some point. Again this isn't something that should cause a typical FRAG.

Any other troubleshooting avenues anyone can suggest?

 

[Mitsurugi-w]

Shoot Ken at irepairsega a question about it.

 

[twistedsymphony]

I feel bad asking him repair questions, since that's his business. If I couldn't get this running my plan was to send it to him anyway.

 

[Mitsurugi-w]

He has plenty of work to do and he is really helpful which is refreshing. I had a few phone conversations with him. He stays pretty busy just with ops, You cab imagine his load when you add us collectors in there.

 

[twistedsymphony]

So this is what Ken had to say:

99.9999% of the time when that fan fails it cooks the XGPU to death. Best thing now is to remove Core from cage and look at bottom side of pcb. It should be same light green as surrounding area. With the tyoe Core you probably have in Type 3, if it starts turning any shade darker, XGPU is toast and not recoverable.

This is what the underside of the GPU looks like:

 

[Mitsurugi-w]

Hmm. Yeah it does look discolored in the photos.

 

[winteriscoming]

Is the GPU able to be replaced?

Also, unrelated to repair, but since you've already got it open... I've not opened a Chihiro and inspected thoroughly, but reading up on the MAME docs, they indicate that there's a PCB that plugs into the USB controller ports on the motherboard. Shouldn't that mean there's JVS to USB built into one of the upper PCBs that could essentially plug into a PC and be recognized as an Xbox controller? That might be fun to play around with in a disassembled state while you work through getting repairs done.

 

[twistedsymphony]

Is the GPU able to be replaced?

I really hope so... but it will need to be done by someone who can do BGA repair.

Hey @Mitsurugi-w, you got your BGA rework station setup yet?

Also, unrelated to repair, but since you've already got it open... I've not opened a Chihiro and inspected thoroughly, but reading up on the MAME docs, they indicate that there's a PCB that plugs into the USB controller ports on the motherboard. Shouldn't that mean there's JVS to USB built into one of the upper PCBs that could essentially plug into a PC and be recognized as an Xbox controller? That might be fun to play around with in a disassembled state while you work through getting repairs done.

Yes there is a board that does that, but it does a shit-load of other stuff too.

On top of the Xbox Motherboard there is a large PCB (about 2/3rds the size of the motherboard) that plugs into the controller ports, the front panel connector (which is for the power button, eject button, and power/status LEDS) as well as the IDE connector and the LPT connector (this is where modchips usually connect, I believe it allows access to a lot of the motherboard functions). Power comes out of this board and goes into the motherboard power connector. The AVIP cable also comes out of the Xbox's AV port and plugs into this board externally.

The filterboard with the power connectors, LEDs, serial headers, dip-switches audio connectors, etc plugs directly into this board, and the JVS and VGA headers are directly mounted to this board.

There is also a large white connector on top of this board that the media board plugs into when attached.

I can take some pictures of this tonight if you want but here's one I found online:

it's actually upside down in this photo when installed you'd flip it over to the left so the VGA/JVS ports are above the eithernet and AV ports... That long white connector is where the filterboard plugs in, and there's a similar long white connector on the back side where the media board plugs in. The back side is mostly empty, aside from the media board connector there's a coin cell battery, some jumpers and that's pretty much it.

that connector near the center of the board is where the controller port connectors are routed.