ukVac.com Homepage
Forum Home Forum Home > Technical > Tech, Maintenance & Repairs
  New Posts New Posts RSS Feed - Sega chihiro leds
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Skin:


Sega chihiro leds

 Post Reply Post Reply
Author
Message
bonehead View Drop Down
Senior Members
Senior Members
Avatar

Joined: 05 Jan 2013
Location: Bedfordshire
Status: Offline
Points: 9637

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote bonehead Quote  Post ReplyReply Direct Link To This Post Topic: Sega chihiro leds
    Posted: 07 Dec 2017 at 9:04pm
I have just tested one of my pickup chihiro units.
All the voltages leds light and I get a green status led but nothing on the screen. It won’t go into test mode or even boot.

Is the knackered?
Cheers
Always looking for a bargain.
Wanted. Centipede uprigh, bezerk, mad planets.
Back to Top
stegrey View Drop Down
Senior Member
Senior Member
Avatar

Joined: 02 Mar 2014
Location: merseyside
Status: Offline
Points: 1703

Feedback: 4.884615384615
Post Options Post Options   Thanks (0) Thanks(0)   Quote stegrey Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 9:14pm
have you got the Avip cable in?

Edited by stegrey - 07 Dec 2017 at 9:14pm
*SMG*
Wanted: Cabs: Paperboy, Daytona
Pcbs: Splatterhouse, WWf the arcade game
Back to Top
bonehead View Drop Down
Senior Members
Senior Members
Avatar

Joined: 05 Jan 2013
Location: Bedfordshire
Status: Offline
Points: 9637

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote bonehead Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 9:22pm
Yes I have that plugged it. I have tested another chihiro and I know the cab is working ok.

Thanks
Always looking for a bargain.
Wanted. Centipede uprigh, bezerk, mad planets.
Back to Top
robotech View Drop Down
Senior Member
Senior Member
Avatar

Joined: 11 Dec 2014
Location: birmingham
Status: Offline
Points: 1437

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote robotech Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 9:32pm
I have three or four of these that I m trying to repair for a mate
all display the same issues as yours
replacing the 6.3v 3300uf caps next to the cpu and re applying thermal paste to the cpu/heatsink is supposed to work but I have not had any luck so far by doing this
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1411

Feedback: 0
Post Options Post Options   Thanks (0) Thanks(0)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 9:53pm
Common fault with chihiro's is an overheating GPU due to the fan malfunctioning.
If the pcb is seriously brownish / decolored under the GPU, this is likely your problem.
I tried to rebake the gpu bga once, but the board stayed dead. (had it done by a company specialised in placing components on pcb's, so no kitchen oven job...)
You need a media board connected to get a picture. The chihiro kernel loads segaboot.xbe from that board. If it's not there, the screen stays black.
I also once had a base board with a shorted protection transorb diode on the sync signal. Due to that, the connected monitor gave me no picture as well. (It was a modern LCD that simply gave me the no video message.)
The green led staying on is a good sign. If the mobo isn't booting at all, it will "frag" like the OG xbox. It will turn on and off the xbox a couple of times after which it will flash the red and green led in sequence (F)lashing (R)ed (A)nd (G)reen.
I am working some time now on a homebrew chihiro bios that works on a memory upgraded xbox board. xbox boards are easier to find and cheaper.
Back to Top
gunblade View Drop Down
Senior Member
Senior Member


Joined: 25 Jul 2011
Status: Offline
Points: 1082

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote gunblade Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 9:58pm
base board can cause this(not the core board)

Back to Top
bonehead View Drop Down
Senior Members
Senior Members
Avatar

Joined: 05 Jan 2013
Location: Bedfordshire
Status: Offline
Points: 9637

Feedback: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote bonehead Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 10:06pm
Ok thanks. I will look a little deeper.
I just get the green led no red or flashing at all.
Always looking for a bargain.
Wanted. Centipede uprigh, bezerk, mad planets.
Back to Top
obcd View Drop Down
Senior Member
Senior Member


Joined: 02 Aug 2014
Location: Belgium
Status: Offline
Points: 1411

Feedback: 0
Post Options Post Options   Thanks (0) Thanks(0)   Quote obcd Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 2017 at 10:21pm
Thinking a bit further, I don't think the chihiro bios is handshaking between it's x86 and the SMC pic processor. If that's indeed the case, it won't do the power cycle thing and it won't start flashing red and green.
My modified xbox board is doing this because it's having different firmware in it's SMC pic processor. A dead main board will likely result in just green being on. My mistake.
The 3 power led's are simply connected to the incoming 12V 5V and 3V3.
The small protection box that sits between the power cables on a chihiro 3 simply turns off all voltages when one of the 3 is missing.
Some of the internally used voltages are generated on the base board itself.  
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.172 seconds.