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Chihiro freeze after 90 seconds

Solkan

Solkan

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Hello,

I recently bought a Chihiro T3 motherboard and, unfortunatly it has a big problem : the system freeze after 80-90 seconds.
Into setup, while netbooting or even doing nothing, the Chihiro stop working (freeze screen) after some time.
I've tried it on 3 different Naomi cab and control the +5V on each while running the board.

If you have any ideas or have had similar problem, please write it down.

Thanks in advance.

Ps : of course, the seller "need money" and refuse to refund :cursing: since it "was working before"
 
The voltage can drop on these at certain times but if you re verifying it isn't dropping too low during play then it can be an indication that the GPU needs to be reballed.
 
The voltage is stable at +5V.

Sorry, english is not my mother tongue : when you write "the GPU needs to be reballed", do you mean I have to remove the GPU and change its thermal paste ? Do you have pictures of the operation ?

I read a lot of comments about the big caps on Chihiro motherboard. Can they be the reason of the freeze ?
 
If the caps are not bulged then they are fine. Reball means someone with special equipment would need to remove the BGA GPU chip, reball the chip, and then reapply the chip to the pcb. Not many people have the equipment or skill to do so.

For more info google "Ball Grid Array"

BTW it wouldn't hurt to try reapplying thermal paste. A cheap thing to try first.
 
wow, impossible job for me :(

So, I will try other easy things to do first.
Open the "chest" and took a look at the caps. They need to be changed at least
20180429171307-Solkan-DSC03145.JPG
 
Those are definitely suspect.

Remove the supercap while you're at it.

Also, don't try removing the heatsink with force. You will likely damage it. Remove it with heat or don't touch it at all.
 
I have a Chihiro with similar symptoms.

I was able to add some bracers (made from some 3d printed scraps) under the GPU so that they push the PCB up slightly underneath when it is screwed down.

It's not an ideal solution, but has kept this particular Chihiro stable since doing it. It's not worth it for me to send it to someone to reball.
 
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Yeah those caps are bulging. Def. need to be replaced.
 
nem said:
Also, don't try removing the heatsink with force. You will likely damage it. Remove it with heat or don't touch it at all.
Click to expand...
Which heatsink ? CPU or GPU (or both) ?
I saw somebody removing those heatsinks and change the thermal paste
 
winteriscoming said:
I have a Chihiro with similar symptoms.

I was able to add some bracers (made from some 3d printed scraps) under the GPU so that they push the PCB up slightly underneath when it is screwed down.

It's not an ideal solution, but has kept this particular Chihiro stable since doing it. It's not worth it for me to send it to someone to reball.
Click to expand...
Can you tell me more about this ?
Not sure I can find a reball-specialist, nor than I can afford the reball.
 
Check the pcb underneath the gpu. If it has decolored into brownish, your unit has been used some time with a non working gpu fan. In such case, the gpu thermal paste can become very hard and it becomes very difficult to remove the heatsink from the gpu. Even if the 2 separate, there will be dryed thermal paste residu on the heatsink and the gpu which are nearly impossible to remove. You need to create 2 flat areas before you can add new thermal paste.

The capacitors being bulged is a second frequently cause of failure. When they dry out, the cpu gets 2 much ripple on it's voltage rails.

The 1 farad goldcap is also a problem item. After some period, it can start to leak. The spilled residu is corrosive and can damage the surrounding pcb tracks and components. You don't need to replace that capacitor, just remove it. It was used in the xbox (nearly identical mobo) to keep the real time clock running when the power plug was removed. The chihiro has an additional real time clock on it's base board that is powered by a cr2032 lithium battery on that board.

The chihiro will only boot and show a screen when it's fully assembled. The upper dimm board contains it's dashboard.
 
obcd said:
The capacitors being bulged is a second frequently cause of failure. When they dry out, the cpu gets 2 much ripple on it's voltage rails.
Click to expand...
This makes sense. Just ordered replacement caps for these 3 bulging guys.
I won't boot up the Chihiro until they arrive at home and try to remove this golden/super cap in the meanwhile.

And before everything : a big thank you to all of you for your help and for trying to revive this Chihiro
 
Solkan said:
Can you tell me more about this ?
Click to expand...
The PCB is screwed into some built in stand-offs in the metal casing. The goal is to get something non-conductive that is just slightly taller than the stand-offs that, when installed under the GPU, will push the PCB up slightly, hopefully making better contact with the flaky BGA connections. Certainly putting something too tall in could cause the PCB to break or make the BGA worse.

This is by no means a trusted method. I just happened to be experimenting with my Chihiro that would barely work and banging on the side of it while on (even in the frozen state) would cause graphical glitches, so I suspected the BGA.

My board looked good under the GPU, but unbeknownst to me the Chihiro was loose in the WMMT cabinet I purchased and probably got banged around a lot while loading it up and driving, breaking some BGA connections.
 
I ordered three of these. Is this ok ? Electronics is not my best part; I'm used to change defective pieces on a one-for-one basis
s-l1600.jpg
 
those will work,
i just like using polymers because they are more compact and arent effected by heat.
 
I had literally the exact same issue, with the freezing and the slightly blown caps. Replaced them and hasn't froze since. Wish I could say I haven't any issues since but this machine has had an issue with every main component, thanks sega.
 
i dont have a chihiro, but if it did then i would replace the gpu heatsink with the taller fanless one used on newer xboxes after 1.0 pcb
i would also increase the cooling.
M$ made a real mess of cooling those boards.
 
The taller fanless heatsink hardly fits in a chihiro as you have the baseboard on top of the main board.
If I remember well, the larger heatsink touches that board.
Rising the baseboard isn't an option either as the upper case with the dimm board plugs into it.

Besides that, it wouldn't suprise me that the gpu is cooler with a working fan than with the larger heatsink. After all, they let it run full speed all the time.

So the only thing they did wrong is the fact that they don't verify the temperatures and shut down the system when they become 2 high.
On naomi, they turn off the system if one of the fans isn't rotating and not generating speed pulses.

Maybe it wasn't even sega but microsoft who developped the chihiro kernel? On xbox, temperature monitorring is a dashboard function. Once you start a game, it's no longer monitorred either.
 
chihiro is xbox/m$
you can run some of the games on a moded xbox with extra ram.
i suspect m$ provided all electronics and a software dev kit/enviroment and sega just provided the case.
 
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