Lenovo thinkcenter mini m93 hit by lightning

[sputnikoff]

I have seven units lenovo think center mini that were hit by lightning.They all have the network blown out.No visible damage just no lights on network when plugged in.I assume its a blown icp fuse somewhere on board.The issue could also be in that cage around network connector.Otherwise the pc operates just fine.

[caspian]

Re: Lenovo thinkcenter mini m93 hit by lightning

is data transferred through the network connector properly?
it would help if you find the mainboard's schematics.

[sputnikoff]

Re: Lenovo thinkcenter mini m93 hit by lightning

no data transferred network side is dead.No indicator lamp when cable is plugged into port.

[caspian]

Re: Lenovo thinkcenter mini m93 hit by lightning

it is really difficult to fix a mainboard without schematics. you can use a USB Lan adapter that provides a cheap network connection.

[piernov]

Re: Lenovo thinkcenter mini m93 hit by lightning

Usually the Ethernet controller IC goes bad, but it gets shorted. Can't see anything on the pictures but there should be an IC somewhere that's the Ethernet controller IC, a Realtek RTL8111, Intel, Broadcom or Atheros IC.
The ESD protection diodes can go bad too. This can be verified by checking for a short to ground on all the pins of the Ethernet port. If some of the data lines are shorted, then most likely the ESD protection diode is dead, you have to find where it is on the board (you can inject voltage like 1 or 2V and check which component is heating).
Lastly, the transformer and the filter cap inside the Ethernet port can be bad. Nothing you can do to reliably check that, but if replacing the Ehternet controller IC and ESD protection diodes didn't solve it, and the Ethernet controller IC is properly powered (voltage on its VCC pins, check datasheet if available) then you can try replacing the Ethernet port.
The Ethernet port (with USB ports) is hard to take out and you could damage the board, so better try it as a last resort.

[RobbieC]

Re: Lenovo thinkcenter mini m93 hit by lightning

Did you find a resolution to this issue as I have a very similar one. I have 2 units which appear to have died post lightening but are completely dead. I have no 5v from U10 (PK5048A) but have 10v going to it but cannot trace where it is switched from.
Again this appears to be a standby voltage which feeds ethernet as standby allowed network leds flashing when powered down on the good board. Any schematics floating for this board ?

[SMDFlea]

Re: Lenovo thinkcenter mini m93 hit by lightning

Did you find a resolution to this issue as I have a very similar one. I have 2 units which appear to have died post lightening but are completely dead. I have no 5v from U10 (PK5048A) but have 10v going to it but cannot trace where it is switched from.
Again this appears to be a standby voltage which feeds ethernet as standby allowed network leds flashing when powered down on the good board. Any schematics floating for this board ?

Theres 2 motherboards, the IS8XT and LITE-ON JC184/JC186 .No schematics for the IS8XT. There is a schematic for the LITE-ON JC184/JC186 ,can`t find a free one though.

[RobbieC]

Re: Lenovo thinkcenter mini m93 hit by lightning

Sod's law - IS8XT. Hopefully have more time and patience to work backwards. Do have access to working units though to assist and swap parts.

[piernov]

Re: Lenovo thinkcenter mini m93 hit by lightning

As I said the first suspect is the Ethernet controller, so check if it is shorted.

[RobbieC]

Re: Lenovo thinkcenter mini m93 hit by lightning

Apologies to sputnikoff for thread jumping, but I think I have a similar issue not the same, however my knowledge of the system is limited and possibly incorrect.
My assumption is the 5v / 3v standby voltage is not there. Be that something failing on the supply line or something pulling the output / input to a fet down. There also seems a SF1 fuse in close vicinity to the ethernet controller which I (maybe incorrectly incorrectly) assume would blow in this case.

Out of interest - on the basis the unit dies from a surge due to lightening, what usually pops ? Am I ok to rule out caps and concentrate of a fet / short on a standby line. Certainly none of the elecrolytics look swollen.