Archive for April, 2012

NPS/RADIUS problem with VMware ESX 4.1 to 5.0 upgrade

Written by on 26th April 2012 in technology with 0 Comments

I encountered a strange problem so I thought I’d post about it.

We upgraded many VMware 4.1 ESX nodes to 5.0, and for the most part it went fine.  However after the upgrade, our wireless users couldn’t authenticate on the internal network, but the guest network still worked fine.  We were using a variety of Cisco access-points and they had worked perfectly fine with RADIUS auth before the upgrade.  I tracked down the error, the RADIUS server (now called Network Policy Server in Windows 2008) was throwing error 266.  This error would indicate it thought it was receiving a malformed packet!  We were using the E1000 NIC driver on the VM’s that hosted the NPS/RADIUS server, and had heard that it could cause problems.

I created a new VM with the VMXNET3 driver, and copied the NPS/RADIUS settings over to this new server, and set the access-points to authenticate to it instead.  This worked fine, so I changed the NIC driver on the old VM’s to VMXNET3, but this did not seem to solve the problem.  For now I just created new VM’s with the VMXNET3 driver and they are working fine, I am not sure what is different or why this doesn’t quite work properly, but if encounter this problem hopefully this fixes it for you.

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Optoma HD700X white lines fix

Written by on 25th April 2012 in technology with 0 Comments

I was given an Optoma HD700X projector for free, but it was broken.  About every 15 pixels across, there was a vertical white line.  I googled a bit and it seems that this happens fairly often on Optoma projectors (even shortly after they are bought).  It found that it was likely the main board that was in need of repair.

I called Optoma, and they said the main board was $270.  Since this was free, I didn’t want to pay to risk fixing it and have it not work, I’d rather put that much towards a new projector!  I noticed that if I pressed on the top behind the focus ring some of the white lines would go away, leading me to think it was a poor solder connection.  Since I already have a projector I thought I would try to fix this myself with a reflow.

Solder reflowing is simply heating the circuit board back up to the temperature it was at when it was created, so that the weakened solder joints liquefy and make contact again.  The HD700X is a rebranded HD65, so I followed partial disassembly instructions from here.  Then I put the board in a pie pan, then a turkey pan (to help dissipate the heat evenly), and put an inch of solder in with it instead of a pop-up timer, and put it in the oven.

Andy is totally just like Julia Child.

Then I set the oven for 550F (has to be above 270C) and waited.

After about 10 minutes, we noticed the solder had melted, the oven was at 465F and still heating up, so I turned it off and opened the door and we waited another 20min for it to cool.

Once it was cool I took it out, we reassembled the board, and it worked*! I was amazed it actually worked.


* Well it worked after I put it back together *correctly*, the power cable from underneath was backwards!

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