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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: speedlolita on September 22, 2012, 11:24:05 AM

Title: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 11:24:05 AM
So I just went to play some R-Type and got no response from my PC Engine.

I typically use it through my RGB amplifier (transistors), and was playing about with capacitors (220uF) on the RGB lines (and composite sync) last night. After getting no image I've removed them and now I get nothing.

My EverDrive light doesn't blip on when accessing the MicroSD card so I assume I've broken something somehow.

I've also tried connecting it to my LCD TV via the regular composite cables.

I typically use it with an Atari Jaguar PSU which is rated 9V 1.2A - although my multimeter seems to think it's 12v which is a bit disturbing.  :shock:

Any idea what's up?
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: Drakon on September 22, 2012, 11:41:25 AM
12v should be fine it's using a 7805 voltage regulator.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 11:46:07 AM
Okay, well that rules that out.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: thesteve on September 22, 2012, 12:48:37 PM
you were messing with the amp setup, could have broken a wire or blown fuse.
check the 5V at the regulator or slot
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 01:01:38 PM
The amp is external and I hook it up to the exterior I/O. A blown fuse seems like the most likely scenario in my head.

EDIT: Here's a picture of the fuse, am I right in assuming that replacing this would fix it? http://goput.it/4bt.jpg (http://goput.it/4bt.html)

I'll probably follow mmmonkey's SNES fuse replacing guide if so and make the fuse socketed.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: BlueBMW on September 22, 2012, 05:18:18 PM
Looks blown to me.  Check continuity between the fuse and ground before you put a new one in and make sure theres not a short somewhere.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 05:39:23 PM
Shame I don't have a multimeter with a continuity test built in, imagine that.

I shall be purchasing a new multimeter and various other tools come payday I think.

Also, this may not be the thread to ask in, but is desoldering braid a good idea if I want to install an 8 pin DIN socket? I've not had much like with my desoldering tool.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: BlueBMW on September 22, 2012, 06:15:10 PM
I love desoldering braid myself.  Though I recommend you use it with some liquid flux for the best results.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 06:17:20 PM
Awesome.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: thesteve on September 22, 2012, 06:30:40 PM
that is not just blown, its short circuit blown
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 07:29:36 PM
What else needs replacing?
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: thesteve on September 22, 2012, 10:26:06 PM
if you know what blew it, just the fuse.
if its still a prob, it wont wait to tell you
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 22, 2012, 11:34:56 PM
Oh I see, silly me.

No as I say, no internal modification so it mostly likely won't short again. I think I plugged the RGB, 5v, gnd and composite video one pin over from usual. I imagine that did it.
Title: Re: PC Engine Core Grafx II Problem, possibly power related
Post by: speedlolita on September 27, 2012, 01:10:46 AM
Yep, put in a 1A axial fuse and all seems to be working now. Thanks guys.