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

NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: mrbungler on October 14, 2025, 06:04:18 PM

Title: Turbo Express seems to be running warm after LCDDRV screen mod
Post by: mrbungler on October 14, 2025, 06:04:18 PM

Hey all,

Did my first LCDDRV 3.5" LCD mod on a TE and it seems to be getting quite warm when operating.  Everything is working great, just running warm so I figured that would probably impact battery life.  My bench power supply says it is pulling ~.48A and ~4.25W which seem kinda high.  I have a crappy "attach to you phone" thermal camera and Q502 is getting quite warm.  Like north of 100C when running for a few mins.  A few other components get to 40-45C but Q502 is the outlier.  My gut says this is probably due to the junky AliExpress LCDDRV that is advertised as a Sega Nomad screen but I heard others have used it on a TE.  Any ideas?  I disconnected the screen and Q502 hovers closer to 50-55C and the system only pulls ~.35A and ~3.3W.  I think that increase in draw is inline with the specs on the AliExpress page.  To be honest I don't remember if this system has video issues previous so this could just be a cursed system. 

Thanks for any advice.
-John

Title: Re: Turbo Express seems to be running warm after LCDDRV screen mod
Post by: mrbungler on October 15, 2025, 05:44:08 PM

Quick update.  I removed the Q502 and replaced it with a crappy variable voltage buck converter set to 5v and hooked up like mentioned on the Retrosix wiki.  That almost halved the values above!  And the hot spot was gone.  I mean I guess that is obvious with Q502 removed.  The only issue is the video signal become very noise when you turned up the brightness.  I will try to swap out the buck converter with a 5v LDO regulator and see if that results in the same power reduction and fixes the video noise.