Jonestown

Itona VXL Thin Client Repair – Part 2

Bringing some old thin clients back to life

In Part 1 I repaired an Itona VXL that would not power up. The next 7 units I checked had the same symptoms and the same problem. The 22uf 400vdc capacitor on the +5vdc standby board was bad/leaking. The problem with this unit is a little different. This Itona powers up and boots to Windows XP Embedded but is unstable and crashes often. First, a look at the P3VB-VXL motherboard.

Looking closer at the front of the motherboard reveals 3 leaking capacitors. All are Rubycon MBZ series rated at 1000uf @ 6.3vdc. Rubycon MBZ are good quality capacitors and normally don’t fail unless there are other problems.

After replacing the 3 bad capacitors with new Rubycon MBZ, I look for the cause of their failure. All 3 capacitors are on the 3vdc rail. A bad capacitor in the power supply on the 3vdc rail could cause the failure of the motherboard capacitors, so out comes the power supply.

The 3vdc board is circled. Checking its output capacitors reveals both have high ESR readings. A normal ESR reading for these capacitors would be under 0.03 ohms ESR, but these are reading from 8 to 12 ohms.

Both of these capacitors are Nippon Chemcon TMZ series which are known for having a high failure rate. For replacements I used Sanyo Os-Con SP series capacitors.

At this point the Itona is back to working like it should. However, since the Itona power supply is full of poor quality capacitors, while the power supply is open I replace all the remaining capacitors.

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