STE - 5.25V?

[coonsgm]

So been working a fair amount with my STE and have found that if the 5V line is between about 5V and 5.15V I have stability issues. From 4.8V to around 4.95V, it's pretty darn stable, but the screen is dimmer than my other ST's. The sweet spot seems to be around 5.2V - 5.25V

Here it's rock solid stable and the video out is normal brightness.

My question here is....is this a normal thing? This is my only STE and I haven't experienced this on any of my other ST's....

Thoughts?

[exxos]

Sounds like you need to do the mandatory fixes.

[coonsgm]

Sorry, I didn't mention that I've already done the mandatory fixes along with the video ghosting fix. :D

[exxos]

Sorry, I didn't mention that I've already done the mandatory fixes along with the video ghosting fix. :D

The bus fixes ? Recapped PSU ? HC CPU ?

Seems odd. I've ramped the voltage right up on machines in the past while messing about. Normally if all the fixes are done things are a lot more stable.

There is a clock buffer chip which if it is a "S" version can cause issues.74S257chip for U405. Should be a F version.

[coonsgm]

Bus fixes = yes
New PSU = RD-50a (just did today) the previous PSU had been recapped a couple years ago...but I hadn't done it myself, so I wasn't sure of the quality of caps / work.
HC CPU = yes

Clock buffer chip....I'll take a look and see which version I have.