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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: GT87 on November 12, 2014, 01:33:09 AM

Title: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: GT87 on November 12, 2014, 01:33:09 AM: Hey all,

So I've picked up a Duo a few months back from Ebay that was labeled as not working. Whoever tried to replace all the caps did a real hack job on this one....... All the caps were the same, the solder was crappy, and a solder pad was missing. There's also some brown gunk here and there (soda?)..

Anyway, I replaced all the caps, cleaned up the PCB as best as I could, jumped a trace to remedy the missing solder pad... and now I'm pretty sure I'm facing a 5v short somewhere that I haven't located yet. I still have to test the entire board with my multimeter to find the 5v points..

Here are the symptoms:
1) when an HuCard is inserted, there's nothing but a black screen and just a sound from the intro I guess (Keith Courage)... the sound is just continuous, and every time you turn it off and back on, a different sound it playing and still continuous.

2) when turning it on without a HuCard to boot a CD, I get nothing but a white screen. Nothing else..

Now I've done enough research to find this issue but I can't put my finger on it. The only reason why I think it's a short is because of a video posted on Youtube by Gametech about a Duo that has a 5v rail short (it did the same thing sort of, although regardless of Hucard or CD).

So if anybody has any pointers, please help me find this issue so I can get this thing rolling!
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: Keith Courage on November 12, 2014, 02:39:01 PM: So when using a hu card you get perfect sound but no video?

Also, have you tried the DUO with a CD system card to see what happens?
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: thesteve on November 12, 2014, 05:22:48 PM: hung sound not perfect sound
work ram error/ could be addressing short/open or bad ram chip
seen bad address pin on CPU do the same
not a 5V rail short as that would be black screen under all conditions without sound
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: GT87 on November 13, 2014, 03:12:53 AM: Hmm.. well, I may have to start fooling around with my logic probe to see if the Ram/CPU are bad.
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: shipwreck on September 17, 2015, 09:08:56 AM: This looks amazing
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: Necromancer on September 17, 2015, 09:25:24 AM: Quote from: shipwreck on September 17, 2015, 09:08:56 AM
This looks amazing

An amazingly obvious way to boost your post count to get in on some raffle goodness?
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: esteban on September 17, 2015, 09:34:56 AM: Quote from: shipwreck on September 17, 2015, 09:08:56 AM
This looks amazing

Indeed. Please explain. I'm very eager to hear your thoughts.
Title: Re: Turbo Duo Issue - Need HELP - Possible 5v short
Post by: thesteve on September 18, 2015, 12:40:23 PM: any progress?