PCEngineFans.com - The PC Engine and TurboGrafx-16 Community Forum

NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: jelloslug on August 27, 2014, 02:55:10 PM

Title: Help repairing a dead TG-16
Post by: jelloslug on August 27, 2014, 02:55:10 PM
I have recently acquired a dead TG-16.  It will power on but only display a colored screen.  The previous owner made several attempts to repair including re-capping the system and reflowing the card slot.  I completely unsoldered the slot and re-solder it and cleaned the slot thoroughly.  I have also check all the connections from the card slot to the 6280 chip.  Any thoughts?
Title: Re: Help repairing a dead TG-16
Post by: crans on August 28, 2014, 11:01:56 AM
Check every via and trace around the compositor for continuity I have repaired many mucked up diy cap jobs.   Look ar all component for solder splash.
Title: Re: Help repairing a dead TG-16
Post by: jelloslug on August 29, 2014, 04:55:12 AM
From what I understand it was dead before the cap job.  I looked over the cap replacement, touched up a few things with no results...
Title: Re: Help repairing a dead TG-16
Post by: bust3dstr8 on September 01, 2014, 02:03:49 PM
Seems like the 6280 isn't booting. I would check the reset circuit (D101, R101, C101) and the clock circuit (R104, R107, C103 and OSC101) If you have a logic probe you can check the circuits directly on the 6280 inputs.
Title: Re: Help repairing a dead TG-16
Post by: jelloslug on September 01, 2014, 02:34:56 PM
Seems like the 6280 isn't booting. I would check the reset circuit (D101, R101, C101) and the clock circuit (R104, R107, C103 and OSC101) If you have a logic probe you can check the circuits directly on the 6280 inputs.
I don't have a logic probe right now but I checked all the circuits and components that you listed and they are good.
Title: Re: Help repairing a dead TG-16
Post by: bust3dstr8 on September 01, 2014, 02:43:29 PM
I would invest in a logic probe...without it your just taking random stabs in the dark.
Title: Re: Help repairing a dead TG-16
Post by: thesteve on September 01, 2014, 06:50:22 PM
also some games get sound if the 6280 boots
the 6260 and 6270 do connect to the data bus and i have seen some 6270 chips with shorted data pins prevent boot
for a tg16 taking it to the hoop should have sound without 60 or 70 chip running
if the screen color changes sometimes the 60 is likely working correctly
note a black screen is typical for 60 and 80 running code 70 dead so no boot is most likely
Title: Re: Help repairing a dead TG-16
Post by: jelloslug on September 02, 2014, 01:57:13 AM
also some games get sound if the 6280 boots
the 6260 and 6270 do connect to the data bus and i have seen some 6270 chips with shorted data pins prevent boot
for a tg16 taking it to the hoop should have sound without 60 or 70 chip running
if the screen color changes sometimes the 60 is likely working correctly
note a black screen is typical for 60 and 80 running code 70 dead so no boot is most likely

Thanks, I'll give that game a shot and report back.  When I power it up I get a yellow-orange screen most of the time and occasion white or some other light color.
Title: Re: Help repairing a dead TG-16
Post by: thesteve on September 02, 2014, 04:38:25 AM
Yes dishwasher,  no anonymous prayer
Title: Re: Help repairing a dead TG-16
Post by: jelloslug on September 02, 2014, 06:45:26 AM
I check the oscillator on a scope and it's working perfectly.  I also check for sound with Takin' it to the Hoop and there was no sound at all.
Title: Re: Help repairing a dead TG-16
Post by: thesteve on September 02, 2014, 05:40:13 PM
then id look for a problem on the data bus