Turbo Grafx 16 / PC Engine / Express / GT Region Mod Chips for sale!

[FiftyQuid]

I usually just double-sided tape it to either the top of the hucard slot or nearby on the system board.  There's so much room inside the TG16 that there shouldnt be much trouble making it fit!  Just watch your wires and the edges of the RF shielding.  At times I've cut away some of the RF shielding to make more room for wires coming and going.  I always tape the edges of cut RF shielding with some felt tape to make sure it doesnt cut anyone should the unit be taken apart again.

Blue have you ever just left the thin RF shield off?  I can see putting the fat RF shield back on without any issues, but the thin one won't fit without cutting it (like you said) with region chip mounted on the HUcard slot or PCB.  Dat shit is tight!

I had to solder the wires for the Motherboard on the opposite side and wrap them back around.  There was no way the soldering gun was going to fit under the HUcard pins without me undoing all the wire work I had done on the HU pins or melting the shit out of my shrink wrap.

[BlueBMW]

The RF shielding is not critical.  It was to meet FCC rf emissions rules.  Note that the pc engine models dont have such shielding and operate fine without them.  The one exception is the Super CDROM2 models which have grounds linked by rf shields and wont work right without them installed.

Bottom line, if you need to cut some of the shielding to make room for your mod, by all means do it!  Just watch the sharp edges when you do.

[FiftyQuid]

I finished soldering up everything 5 minutes ago.  All the connections look good.  H goes to the HUcard side and P to the PCB for all the pins.  I didn't have a SPDT switch so I ripped up an old clock radio and reused a switch from it.  Then I carefully put the motherboard into the housing and slid the TG-16 into the expansion for my TG+CD docking base.  I tossed in a spare Keith Courage and flipped the power switch.  The TV screen went white.  So I flipped the switch for my old clock radio.  No change.

I'm thinking the switch is no good.  It's a 2 position switch, but it has 6 solder connections.  It was only ever meant to be temporary.  I just wanted to test my install and it was the only thing I could find.

[BlueBMW]

You can temporarily just connect A to B or B to C to test without a switch.

[FiftyQuid]

You can temporarily just connect A to B or B to C to test without a switch.

Yeah, I tried A to B and B to C, but I get the same results.  Just a white TV screen.

I measured pin 38 just to make sure I was getting voltage.  This is the pin I used to power the region mod chip.  I'm getting 5V so power is getting to the region mod chip.  I also triple checked the wiring just to make sure I didn't have pin 19 going to 20, or an H going to a P.  Solder connections look good so I'm a little stumped at what to try next.

I also took a volt meter and measured A, B, and C.  I get 5V on pin A, but 0 on the others.  I'm going to take some isopropyl alcohol and clean everything up next, but after that I'm not sure what to do.

Any advice?

FYI, I'm confident with my solder work.  I went to college for an Electrical Technician course where 50% of our grade was lab work involving soldering.  I've done mods like this before, and have to work with PCB's quite frequently.  I'm trying to tell you I'm competent. 

[BlueBMW]

Hmmm...  It sounds like youve verified each line is correct and youve got good 5v and ground....   I can see no reason why it wouldnt work... I havent had any chips come back bad yet, though I suppose it is possible.  Kf you are certain all the lines are connected correctly then I can only suspect it might be a faulty chip.  I can send you another one asap if youd like.  Though Id hate to make you have to solder another one.

[FiftyQuid]

Hmmm...  It sounds like youve verified each line is correct and youve got good 5v and ground....   I can see no reason why it wouldnt work... I havent had any chips come back bad yet, though I suppose it is possible.  Kf you are certain all the lines are connected correctly then I can only suspect it might be a faulty chip.  I can send you another one asap if youd like.  Though Id hate to make you have to solder another one.

I'll keep you posted.  I plan on resoldering the entire thing this weekend so I'll find out if it's me or the chip.  I would have done it tonight, but I ran out of desolder braid.

Have you ever tested the region mod chip using a TG+CD docking base?  Also, I read something about grounding pin 29 back in the first few initial posts of this thread.  Maybe that was for a Duo?

[BlueBMW]

Pin 29 is for japanese systems to disable a hardware region lockout.  Shouldnt matter if youre using the system with a cdrom base or not.

[FiftyQuid]

Pin 29 is for japanese systems to disable a hardware region lockout.  Shouldnt matter if youre using the system with a cdrom base or not.

Thanks for clarifying.  I will keep you posted.

[thesteve]

with the cart removed the mod can be tested with a meter
it works just like a switch (with a few ohms in the chip)
so you should be able to measure the continuity from the motherboard to the slot

[FiftyQuid]

with the cart removed the mod can be tested with a meter
it works just like a switch (with a few ohms in the chip)
so you should be able to measure the continuity from the motherboard to the slot

Makes sense.  I don't like the location so I'm going to move it to another area of the MB.  This means resoldering pretty much everything, but once I'm done I'll definitely test the continuity at the HUcard slot.

Can I assume that B to C (measuring 0 volts) is for NTSC and that A to B (measuring 5V) is for Japan?

[thesteve]

thats correct

[FiftyQuid]

Still no luck BlueBMW, and thesteve.

Last night I removed the region mod chip (RMC) and every piece of wire I had used.  I threw the 26 gauge wire I had used into the garbage and replaced it with some 30 gauge stuff from my workplace.  The sheathing has an extremely high threshold to heat and I find it easy to work with so I figured I would try it.  I replaced every single piece of wire and started soldering everything back together.  When I was done I inserted a spare KC HUcard again and inserted the raw MB into the expansion bus of the TG+CD docking base (I wasn't reassembling everything again to test it out).  I connected B to C with a few simple twists, powered up the docking base, and then powered up the TG-16.  Same result - white TV screen.  To be thorough, I removed the KC HUcard and inserted Legend of Hero Tonma (PCE) instead.  Then I connected A to B and powered everything up again - same result (white TV screen).

Disheartened, I grabbed my multimeter and checked for connectivity from the "H" connections on the RMC to the HUcard slot.  I used the underside of the RMC for checking connectivity.  All 8 wires passed.  I did not check the connectivity for the "P" connections as these 8 wires are the shorter of the runs and also much easier to solder.  It was also midnight. I did inspect them visually and they look perfect.

Tonight I will check the "P" side for proper connectivity and I will also install a proper SPDT.

In the past, or when you guys install the RMC, do you reassemble the entire console before testing?  I don't want to put the whole thing back together without making sure it passes first, but I'm wondering if the RF shielding needs to be there for proper ground.  I have my doubts.  I am really just grasping at straws here.

[BlueBMW]

I always test them apart... but on the tg16 I dont run it long since part of the rf shield acts as a heatsink for the voltage regulator.

If you still have no luck, Ill mail you another chip or two and some cash for your wasted time.

[FiftyQuid]

I always test them apart... but on the tg16 I dont run it long since part of the rf shield acts as a heatsink for the voltage regulator.

If you still have no luck, Ill mail you another chip or two and some cash for your wasted time.

Don't send me any cash!  If I ignore the fact that I can't get this thing working and that there's been no payoff, it's still been a fun and interesting project.

Do you really think it's the RMC?  I mean there's only a single component on it.

Here are a few pictures.  Maybe I'm missing something plain as day.  This first pic is me unpackaging the brand new RMC from the Ziploc.  I was concerned about some of the solder on the chip.  In the picture you can see there is already solder filling holes 19P and 21H on the PCB.



Here's a shot of my second attempt at this installation.  It's the underside of the TG-16 MB.  I'll post a shot of the top side (HUcard side) tonight.  I just happened to have this underside pic on my phone.  On my first attempt I mounted the RMC on top of the HUcard slot as you show in the instruction manual, but I didn't like the placement (I didn't want to cut anything) so I relocated it when I had to redo all the soldering.



Do you see anything I may have missed?  It's hard to tell in the pic, but who knows.