Power on - restart boot loop - RAM issue?

[coltron]

Hi hope someone recognises the symptoms and can identify a fix?

Lenovo E530. i3 3110, no discrete graphics, new grease applied.

When power button pressed the laptop appears to make the right noises, but restarts 3 -4 seconds later with a continual boot loop approx 10 reboots before shutting down.
Pess the button again and the same happens.

I,m thinking the mobo shorted somewhere?

Checked motherboard for signs of short, eg usb ports for bent pins etc.
Board looks clean.
Thought bad RAM, when RAM is taken out of the board the laptop will power on without restarting, so I'm onto something?
.Used known good RAM..no different regardless of slot position.
Checked the ram slots for debris, appears ok
checked the ram in another computer work fine.
which makes me think the problem isn't a visible short

Done some multimeter diode mode checks on the power rail coils and

Vcore coil is only 3 ohms while CPU is in the board, took the cpu out and low ohms disappears. I,m fairly new to diagnosing laptop faults and would like to know if the low ohm reading is normal for 3rd gen i3 processor?

Any help appreciated

[mcplslg123]

Re: Power on - restart boot loop - RAM issue?

Low ohms is ok but should have been a little higher for 3rd gen cpu. You can ignore that for the time being. Have you tried replacing the processor?? Bios flashed?? First take these steps .However, going by my experience, it can be bad vcore IC or surrounding components or bad kbc.

[coltron]

Re: Power on - restart boot loop - RAM issue?

Thanks for your reply

Ive re-inserted the same cpu, but no luck so have a replacement on order.

No Biosflash attempted, however i believe this board is duel bios, not sure what that entails..?how do i flash when board stays on for 4 seconds?

bad kbc, i,m unsure of the term kbc means?

thanks for your insight I will get the DTM to work around, all help much apreciated

[rediii]

Re: Power on - restart boot loop - RAM issue?

Thanks for your reply

Ive re-inserted the same cpu, but no luck so have a replacement on order.

No Biosflash attempted, however i believe this board is duel bios, not sure what that entails..?how do i flash when board stays on for 4 seconds?

bad kbc, i,m unsure of the term kbc means?

thanks for your insight I will get the DTM to work around, all help much apreciated

you need an external programmer (there are cheap programmers available, but you need a working device and soldering skills are required or a clamp). if there are two bios chips it is mostly common that one is for the me region and one for bios region.

the kbc is the big qfn-128 (pin) ic (microcrontroller). one of the most common faults, especially on lenovo laptops... this could be a bit tricky, especially if it's flashed and need reprogamming.

[coltron]

Re: Power on - restart boot loop - RAM issue?

Thanks for your reply

with regards to 2 winbond bios chips "me region"? , I thought one was a back up/ bios restore chip?

I see the kb90 12qf, looks ok under the loupe, is there a way to test this chip?.

thanks for your input

[coltron]

Re: Power on - restart boot loop - RAM issue?

i will look for a bios programmer, but which bios chip would i de-solder?

a schematic would be great

[rediii]

Re: Power on - restart boot loop - RAM issue?

i will look for a bios programmer, but which bios chip would i de-solder?

a schematic would be great

you should flash both chips then. just ask for those .bin-files here.

[coltron]

Re: Power on - restart boot loop - RAM issue?

thanks, i have a programmer ordered off ebay

[coltron]

Re: Power on - restart boot loop - RAM issue?

Update:

Recieved replacement CPU.
CPU Fitted, the Vcore supply coils measured 8 ohm, which is 5 more ohm than the old cpu.
Pressed the power button and powered on for 3 seconds, then restarted.
I,m pinning my hopes on a bios flash....
Flash programmer should be here any day...

[piernov]

Re: Power on - restart boot loop - RAM issue?

3 ohms to ground on CPU VCore for a mobile Ivy Bridge CPU is fine. Can even measure down to 1.5 ohms sometimes.

[coltron]

Re: Power on - restart boot loop - RAM issue?

thnks for responce.
Vcore ic has been mentioned in previous correspondance with mcplslg123. I noticed the boardview link, all i need now is a schematic?

i will do a search on here for it
thanks Piernov

[coltron]

Re: Power on - restart boot loop - RAM issue?

Any one got a schematic for lenovo E530?

[rediii]

Re: Power on - restart boot loop - RAM issue?

Any one got a schematic for lenovo E530?

here, hope it helps

[coltron]

Re: Power on - restart boot loop - RAM issue?

Thanks rediii

I recieved a bios programmer today, wondering how to go about using it?