New Linear Reg PSU. PC won't boot

[iain]

After hours of, I thought, careful construction of a dedicated Regulated LPSU and much testing of wiring. I tried to boot up and the system won't load, I get the bios screen for a few seconds then a blank screen before it cycles around.

I tried booting without the SSD, to see if I could just get into bios and now the screen says "insert a proper boot able device." before this it tried to load recovery files.

I have measured the voltages during boot up and they only dip marginally.

I have tried to put the old ATX supply back in, but only connecting the CPU, SSD and 24pin ATX, and nothing happens at all with that. disconnected I get 5V on the SB pin, so it is not dead. but in situ, nothing on other pins that I tested

I made all the the connectors and wish now I had cut off the old ones and used them as I am worried one of these (SSD?) might have damaged the SSD, as this was the most fiddly connector, but there is no continuity between the pins.

I have 4 rails 12, 3.3 and 5V with a separate 5v for the USB card.

The motherboard is a Biostar H81MHV3 V7.0 WITH AN I3 and air cooled. Wire is silver all over 1mm. I have wired every pin as coloured, to the relevant voltage with grey and purple to 5V. I have not commoned all the grounds, but split them between the voltages as they are all commoned on the MB.
obviously would like to get this going and to understand why the old PSU no longer works in the PC? Does its apparent failure help to explain what the current problem is?

Any help would be vey much appreciated.

worried i have trashed the MB, SSD or the CPU! And want this to work of course.

Cheers

Iain

[Fran]

Could you put a bootable usb stick with a linux distro on it just to see if the rest of the PC is ok? Then you can go back and try the SSD as an external disk to see if its OK etc... and if you can't read it then you know there's something wrong with it. If it still won't boot even from a live usb stick then its something else.

[iain]

Thanks Fran.

I have a suitable USB drive. Will Linux Mint do it? Cheers

[tony]

Can you PF11 on boot up to get to the motherboard screen? You could look at the voltages there. The problem I often get is on the 12v. It just peters out below what is good enough to give a boot up.

What regulator are you using for the 12v?? The audiowind one I use I reckon is just not good enough to keep a steady 12v supply. Grand for 5 and 3.3.
I have to use a motorcycle 12v battery charger to keep things high enough to keep the PC up. Sorry I am using batteries I take you are not.

[iain]

Hi Tony
This is, of course, all you fault. As I got my Lampizator and PC after meeting you and listening to Pearce's gear on your Quads at Scalford!

I can't get into the bios, even if I do the screen goes blank and the cycle of rebooting restarts.

measuring the 12V rail on start up I get swing of around 2 to 3%. dropping to 11.57. Which makes me think trying to boot from another device, wont work either.

I have a very simple 25V supply I could step down to 12, using an old Naim regulator and see if that does it.

or I could get a car or leisure battery in? (not using any batteries in this build)

Cheers

Iain

[tony]

:) That's a long time ago! Apologises if it is any consolation Nigel and Pearse have both got graveyards of mobo's from working on this stuff.

My guess is you have not got enough voltage to power up the pc. You will need to get a supply on it that is over the 12v. I have had constant problems over the years with similar issues to yourself. At the moment I am back on a pico supply to the board. You could try that to see if gets it to boot up as there might be a problem with your 24pin mobo connector. For whats it worth I have a lovely 2 external clock board done by Nigel that I am trying to resurrect. I had similar issues as yourself as my picoless 24pin connector is not powering up the pc. It worked for years. I have got another streacom case secondhand and will set that up and then try and get a spare mobo setup to boot up again picoless.

Most of my problems are down to not putting the lid on it and tidying it up properly at the start. NIgel had kindly got me up and running quickly but the initial job ended up being the long term production model :)

[iain]

Bit more info. If helpful. The old PSU Is still working. Grounded the green wired pin And all ATX pins have the correct voltages. So looks like it may be the ATX socket? How can I test that. The pins look fine?

[Fran]

ok, well thats good news. That means there's nothing wrong with the motherboard etc. So you are looking at the power supply in that case. Mu bet is either a rail is dropping below what it needs to be for a short period (and it'd have to be lower than a few % - 10v for a 12v). The other possibility (not disparaging your skills) is a missing or wrongly assigned voltage line. Are you using a picopc adapter or something similar?

[iain]

Not quite. Wasn't clear enough in my last message The old PSU appears to work as tested. But not when reconnected. Back in the PC it does nothing. I am trying to get an old pc to try both my old and new PSU on.

Hoping to get some from an IT dept that are chucking out old, but working ones. So doesn't matter if I damage them.

Then I can try different configs of the parts .

I tried a Linux USB boot, but same prob, starts to boot then goes blank and starts again.

So frustrating. This was originally an Item Audio build. So the MB should work with a RLPSU.

[tony]

A picture might help of exactly how you are set up. Not sure Fran on 10.5V. On my MSI board it needs to be close to 11.95V to boot up. You might get it to bios alright at 10.5V I think Iain you need to check as you are doing with another PC to see if either supply will power a PC up. Then your problem is narrowed down.

Itemaudio Mark that brings back memories also! I checked online looks like he has wound up or gone out of business. He was a character.