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Display issues after DIY power fix

7800 Power Supply Issue Problem Psu

5 replies to this topic

#1 JaguarRage OFFLINE  

JaguarRage

    Space Invader

  • 26 posts

Posted Thu Nov 23, 2017 2:00 PM

I was given a PAL 7800 recently. The unit came as-is, untested with neither the power supply or controller, but 2 games including DKJr (One of my favorites), so I was pretty chuffed.
I searched online for some info on a quick fix, and ended up hardwiring a SEGA MegaDrive 2 PSU.
The console powers on and plays games!
However, after a minute or two of play, the screen will crackle and the picture will disappear, only to glith back to normal seconds later. It repeats this process every few minutes.
This issue has reoccurred every time I've tested the system.

Any pointers folks?

#2 Mitch OFFLINE  

Mitch

    Quadrunner

  • 6,499 posts
  • 7800 Guy
  • Location:Southern California, USA

Posted Thu Nov 23, 2017 2:11 PM

So it is a PAL-I 7800? Are you using a crt or LCD tv? Old school rf connection? Or some kind of adapter?

Mitch

#3 SmittyB ONLINE  

SmittyB

    Chopper Commander

  • 143 posts

Posted Thu Nov 23, 2017 2:14 PM

It sounds to me like it's just warming up and the frequency is drifting slightly. I have the same with my 7800 and I just ended up tuning it differently on my TV.



#4 JaguarRage OFFLINE  

JaguarRage

    Space Invader

  • Topic Starter
  • 26 posts

Posted Thu Nov 23, 2017 2:21 PM

I'm not sure if it's pal-1, I'l check tomorrow. It's tuned to a fairly new flatscreen as I'm in the process of replacing my CRT monitor.
Could it be an issue with the RF on the consoles behalf? Either way, I'm planning to mod it so I can hook it up with composite.

#5 JaguarRage OFFLINE  

JaguarRage

    Space Invader

  • Topic Starter
  • 26 posts

Posted Thu Nov 23, 2017 4:37 PM

Yup, PAL 1

#6 Mitch OFFLINE  

Mitch

    Quadrunner

  • 6,499 posts
  • 7800 Guy
  • Location:Southern California, USA

Posted Thu Nov 23, 2017 5:38 PM

I suspect it maybe your tv. If you have a crt tv to test with that would be the easiest way to go.

Mitch





Also tagged with one or more of these keywords: 7800, Power, Supply, Issue, Problem, Psu

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