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[Repair log] Random reset, black screen on start up - TRIFORCE III

GeoAnas

GeoAnas

Student
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Polygyros - Chalkidiki - Greece
Hi there!

"Random reboot/resets" and/or "black screen during power on", seem both common problems on many aged TRIFORCE III arcade systems.
These puzzled me a lot till I found that culprits were the smd capacitors on base board. Excessive heat inside the metal cage in combination with prolonged working hours is the cause that leads to smd caps deterioration. Those tend to completely dry out, leaving some kind of sticky residue underneath them. This is likely giving rise of all voltage issues and random system multiple reboots.
:cursing:

Base board is laying on my "operating table" ;-) ...and yes, I applied some heat sinks and kissed goodbye the "bastard" super cap near the battery
DSCN0016.jpg


Burn marks found under the pcb...
DSCN0021.jpg


Twist and Pull...This is my method to root out the evil... ^^
DSCN0017.jpg


Sticky or dried out residue remaining (was well hidden underneath the caps)
DSCN0018.jpg


Straight to the trash bin...
DSCN0019.jpg


All caps have been replaced by quality replacements (25V) Both my Triforces are operational again!
DSCN0020.jpg


Here comes the list:

Cap specification / Quantity

470uf 6V -> 5
220uf 6,3V -> 3
100uf 16V -> 4
47uf 6V -> 4
47uf 16V -> 3

This is more than enough to fix your problems ...but I did not stop here. I also replaced all caps to the other boards of my Triforces and to my NAOMI I system, cause I am a nitpicking kind of person :)
If you are interested, I can post those cap lists here as well


:thumbsup:
 
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Interesting.

I always thought the culprit for the reboots was the CPU overheating as the heatsink and the CPU are a good 1-1,5mm apart (as opposed to being flush).

Will try this!
 
same problem occurs with pc engine duo's - those caps cause all sorts of oddness to occur.

Did you have any pad damage with the twist-n-pull method?

I usually clean off cap residue with a cotton bud and isopropyl before fitting the replacements
 
penrhos said:
same problem occurs with pc engine duo's - those caps cause all sorts of oddness to occur.

Did you have any pad damage with the twist-n-pull method?

I usually clean off cap residue with a cotton bud and isopropyl before fitting the replacements
Click to expand...
Never had a PC Engine duo, must be a magnificent machine...Worst cases I believe were PC Engine GT and of course Game Gear early hand held consoles...It is unlike to find a good working one, with full sound and good display, without being treated with some sort of internal intervention ;-)

Any pad damage? Oh! Yes...when I was a beginner. Now, I've got all the experience and skills to have the work done without any harm to the machine ...and to my nerves as well... ;-)

Of course...Cleaning the pads with isopropyl alcohol is an essential step to follow. It is 'lethal' to leave behind this toxic waste! LOL
I forgot to mention it, so thanks for the reminder ;-)
 
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Black screen on power on is my issue on my current Type 3. I'll give this a try.

Just to be clear, there's no audio during the black screen, right? I'm getting black screen and no audio.
 
winteriscoming said:
Black screen on power on is my issue on my current Type 3. I'll give this a try.

Just to be clear, there's no audio during the black screen, right? I'm getting black screen and no audio.
Click to expand...
Yes, that's the case...no audio at all, just a black screen and some instant twitch indicating that Triforce III is on. Screen remains black...
 
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It would be great if we could get a cap map together, or at least a cap # to value for each cap. Any chance you have that in your notes?
 
That's an excellent idea!

Unfortunately not, I haven't this info in my notes but the board is still on my bench so I will gladly do it tomorrow (it's getting late now in Greece and I have to walk both my kids straight to bed ;-) ).
 
I just replaced the caps on mine with the black screen of death and got it booting! I'm so excited. Thanks for the recommendation.

Here are the cap #'s with the codes printed on each (in the order I had them written down, so not ordered well):

Code: 
C62 - 37 470 6v
C58 - 3F 220 6.3v
C56 - 37 470 6v
C47 - 3F 220 6.3v
C57 - 35 47 6v
C49 - 3F 220 6.3v
C60 - 33 100 16v
C37 - 37 470 6v
C34 - 37 470 6v
C32 - 35 47 6v
C18 - 33 100 16v
C15 - 33 100 16v
C16 - 35 47 6v
C17 - 35 47 6v
C8 - 34 47 16v
C5 - 34 47 16v
C4 - 33 100 16v
C2 - 37 470 6v
C13 - 34 47 16v
Edit: Reminder: If you're changing caps on the Triforce, pay attention to polarity. Each cap spot on the Triforce baseboard PCB has a + sign to indicate which pad is positive. Radial caps tend to have markers for the negative terminal, so make sure to have that one on the other pad not marked with +, and double check orientation before powering on. They're oriented every which way on this board, so make sure to pay attention.
 
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Good work @GeoAnas I am surprised no one is ever done this for the Naomi 2 yet. Come to think of it I have a Naomi 2 with the same exact symptoms as the triforce here random freezing sometimes black screens at boot and like the Triforce the Naomi 2 is all SMD caps. I must mention I tried a bunch of different power supplies with this namoi 2 and the same thing always happens. I will make a list of the caps and do this fix to my naomi 2, thanks again for the info.
 
Just did it for a NAOMI I system as well.The system works like a charm now ;-)
Please don't ask me for a cap list because I forgot to take notes...but I do remember there were LOTS of them!
 
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cruzlink2 said:
@'GeoAnas even if you didn't make a list would you please take some pictures of your naomi 2 recap?
Click to expand...
Gladly, but it's a NAOMI-I system...Here they come....

Looks nasty, doesn't it?
DSCN0022.jpg



Here is the "after" stage...
DSCN0023.jpg


During process...4 more left...

Warning
Be extra careful not to break the pads and pcb tracks!!! I cannot recommend this to a beginner. The whole process is hard and certainly requires some advance soldering skills...

DSCN0025.jpg
 
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You should consider using SMD solid caps for replacing old SMD electrolytic caps. They're about the same price, will never leak, and a much smaller foot print compared to radial dip electrolytic caps. Just be cautious, the stripe side indicates + on these, where its usually - on other caps.

Nice repairs! Thanks for sharing.
 
cpsystem3 said:
You should consider using SMD solid caps for replacing old SMD electrolytic caps. They're about the same price, will never leak, and a much smaller foot print compared to radial dip electrolytic caps. Just be cautious, the stripe side indicates + on these, where its usually - on other caps.

Nice repairs! Thanks for sharing.
Click to expand...
Do you mean the yellow ones with J-bent terminals? Those are tantalum caps.
You are right, they do not leak. They explode. :)
 
I bought a Triforce listed as broken on eBay. It was listed with this description:
eBay seller said:
when tested triforce picture comes up then screen goes black and will not load game
Click to expand...
I got it today and it booted and had boot screen audio, but video wouldn't sync well in spite of filter board DIP switches set correctly, and there where black bars in the video. I didn't leave it on very long in this state, but it once faded to black completely.

I tore it apart, recapped the baseboard and crossed my fingers...

I'm very happy to report that this process has resurrected yet another Triforce for me!

I'll be replacing the noisy case fan, but otherwise not bad at all for $150 shipped. My cheapest type 3 so far, and I didn't have to source it from Japan. :thumbsup:
 
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