Tag: botch

Post #100 HP 6644A refurbishment (#P14)

Not that anybody cares, but this is actually post number 100 already. I prepared something else that failed (to be reported!), so this one has to do instead ;)

My “lab” power supply situation is ageing and often no longer up to the task, think of LEDs north of 35V or anything that takes more than one amp at voltages that cannot be provided with common computer supplies (3.3V, 5V, 12V, 19/20V) easily. So this is part one of the refresh.

I bought a HP 6644A power supply around six weeks ago off eBay, at 245€ including shipping and rack mounts via best offer. […]


A beefy electronic load (#P4F1)

Well, that was a long week…actually, it was a fortnight ;)

Here we go!

(the alignment of images really sucks when placed near the header of the post – thanks WordPress!)

So this puppy was manufactured by my new friends over at OSH Park (ordinary order, no extras) and I think I hit the express jackpot. I registered on June 8th and submitted my files – three hours later (1 AM my time on Friday) I already got notice of the panel assignment. Maybe the small size of 54mm x 31mm (2.1″ by 1.2″ for the Yankees out there) just made a perfect fit on the remaining board size and they sent it straight to production ;) As OSH Park charges 5 dollars per square inch of board area (for three units!), these were 12.75 USD including the free standard shipping. […]


Lenovo Thinkpad R400 LED Display backlight fix (#P3)

Yes, it’s running in the “projects” category, as “quick and dirty weekend fixes” isn’t available yet :mrgreen:

While I was hosting my brother, he casually asked me when I will fix his display. Umm…what?
Turns out, his Lenovo R400 was showing vertical stripes again. Like these:

(jup, stolen from some Apple customer help page – I didn’t take a photo at the time. I guess the bug is a watermark, isn’t it?)

I’ve already seen and kind-of fixed that on my visit shortly before Christmas last year, when I basically had no tools available. […]


USB 2.0 4-Port Aluminum Hubs … and Chinese manual labour (WHL #20)

Hey :)

For today’s blog post I have something that I found at work yesterday. It’s a plain old USB 2.0 hub in an aluminium case, which is used inside of our measuring equipment. Just a jellybean part, it’s sold as Logilink here but I bet other brands just slap on a different logo on the front and they’re good to go. We chose this because it is relatively small, has all USB jacks flat in line (the smaller ones have 2×2 configuration or tend to stack them), and can make use of external power supplies, rather than sucking too much from the uplink port. […]