Certainly if there are electrolytic capacitors, renew these first. The lifespan of electrolytic capacitors is limited. And affected by heat.
All series regulators of the LMxxx or 78xxx type need suitable capacitors on both the input and the output. Otherwise either the regulator feedback system (in the on board chip) may cause oscillation of the 5V rail (which also affects the input supply). Or it will be unable to correctly handle noise on the input supply.
If after fitting new capacitors, there are still problems, the 7805 may have been partly damaged, so yes, try fitting a new one. Having said that, the 78xxx regulators are fairly hardy and don't often go wrong (unless mistreated).
Mark
SuperQBoard Affecting Display
-
1024MAK
- Super Gold Card
- Posts: 593
- Joined: Sun Dec 11, 2011 1:16 am
- Location: Looking forward to summer in Somerset, UK...
Re: SuperQBoard Affecting Display
Standby alert “There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)