Twin Famicom no power/hot MF'n ram

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
451
So I had a twin fami that worked well and I decided to recap it. Easy enough, everything gets swapped out and I double check things like polarity and solder joints before I decide to fire it up. Well when I went to boot it, the power indicator flashed briefly and then nothing. A few hours go by and I can't figure out what's wrong. I had just about given up when I found that the 2 ram chips TMM2015BP-15 get super fucking hot. This is an obvious sign of a short/bad ram and so now I'm trying to figure out how that happened. I also noticed that my junk neo mv1fz has two ram chips with the same pinout and what seems to be similarly matching specs. Would swapping in those be an option? I'm tempted to try but I worry that I'll just fry some more ram.
 

daskrabs

Belnar Institute Student
10 Year Member
Joined
Aug 23, 2010
Posts
1,238
Those chips almost never fail on a Famicom. Maybe check the input voltage first? Smells like a bad voltage regulator or related part/solder joint.
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
451
Those chips almost never fail on a Famicom. Maybe check the input voltage first? Smells like a bad voltage regulator or related part/solder joint.
Checked the main regulator and it came back fine, that was my initial thought.
Let’s not miss the main lesson to be learned here…
LOL yes my bud Traveno gave me plenty of shit, still not sure why it went wrong tho :unsure:
 

ebinsugewa

Rosa's Tag-Team Partner
Joined
Jul 7, 2013
Posts
2,480
You might've bridged a solder pad to power/ground when recapping. Triple check your work. I doubt changing the RAM will make much difference. If you check with a multimeter, do the 5v input pins on the RAM have continuity to ground?
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
451
You might've bridged a solder pad to power/ground when recapping. Triple check your work. I doubt changing the RAM will make much difference. If you check with a multimeter, do the 5v input pins on the RAM have continuity to ground?
Yes solid continuity, not the typical beep that some boards give. I thought that too but I've checked over and over. At this point I'm thinking the ram has internally shorted and I'll need to remove them and check the board for shorts again.
 
Top