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Need to turn on 486 twice to boot?

Fanatik

Experienced Member
Joined
Jan 28, 2018
Messages
223
Since installing a 586 Evergreen upgrade chip and a Dreamblaster I need to start the 486 twice to boot. Is this a power supply issue? It only happens after allowing it to sit overnight. First try the power led illuminates but will not boot or display anything, second try everything starts as it should.
 
One thing that comes to my mind: something has to warm up before it works correctly. In 1988 I had a problem with an HDD when it was cold: the PC didn't find an OS. After letting it run for five minutes and then pushing the reset button the PC worked fine.
So first this question: do really need to power cycle the machine or have you tried pushing the reset button but that didn't work? In the last case I have no idea what else could be going on now.
 
I'm running a cf hdd. There is nothing displayed during the first boot attempt.
 
So my immediate thought when I read this was "bad caps" So I'd suggest you start there. Look for any that seem bulged or leaking.

Check the voltages on the PSU to make sure they are all where they should be, and if they are way low, then I'd pop the PSU open and check out the caps in there. After than, I'd carefully inspect the capacitors on the motherboard for leaks and bulges. Especially any around the CPU.
 
Had that happen on my Packard Bell after I upgraded to a better BIOS, before the Micro Firmware and installing a CR1220 battery holder on the motherboard. There are a few suspects:

0001) Power Supply.
0010) Cold, cracked, or broken solder joints and traces.
0011) Capacitors (tantalum or electrolytic).
0100) Bad components (HDD, FDD, ODD, I/O cards, memory, and other stuff).
0101) Jumpers for the CPU not correct or a BIOS that cannot handle the Evergreen 586 (OEM manufacturers have a hard time with those, unless a better BIOS is installed).
 
What voltage am I looking for and which wires? I believe the two center black wires are ground?
 
a BIOS that cannot handle the Evergreen 586 (OEM manufacturers have a hard time with those, unless a better BIOS is installed).

I had this problem with an IBM machine. The manual states it's expecting Intel Overdrive CPU, but I figured I could pop an Evergreen in there instead. Nope. It'd only turn on about a fifth of the time, then. With the 100 MHz Overdrive installed, the machine boots every time.
 
It started to happen almost every time earlier today. I switched power supplies and the brand new one I bought is junk too. I borrowed another psu and installed. So far, so good. I'll know for sure tomorrow morning after it sits all night.
 
I forgot to mention that the Evergreen upgrade chip worked flawlessly for the last week. I just tried to start it and it failed to boot again the first time. Not good...
 
I just noticed that I had the jumper on the Evergreen cpu wrong. I didn't have it in the Overdrive position. Hopefully it didn't damage something. After moving the jumper it still didn't boot the first time.
 
I changed the cmos battery and re-seated the memory and chips, still acting up.
 
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