Welcome back! It's been a busy month for me with my RL job and a convention to take care of, so here's a bit simpler video, just to keep the rythm of releases up, OK! I still have quite a backlog of tinkering video material and hopefully a bit more time in the coming weeks, so expect another one soon-ish. For this installment, I did some repair on older LCD games. Most of you might not even remember those little time killers of the 80s. A friend asked me to have a look at two of these and a Gameboy Color cartridge. I was unsure about how much I could do for these, as the designs are not really made for servicing, but hey, they were not working now, what could get worse by trying? I know that the battery replacement would benefit from a battery that includes the contacts, but I couldn't find a reasonable replacement when I needed it, so the next best one that fits and has the right voltage had to make do. Special guest appearance by Eddie McBadger! Music: My Train's A Comin' Unicorn Heads (YouTube Audio Library) ... https://www.youtube.com/watch?v=YOCQ9HGizXU

Workshop Project #31 - HP1607A Logic Analyzer This time on the bench: a very early logic analyzer. The HP 1600A model that I restored about a year ago (link below!) has a companion model: the 1607A. During the 1600's restoration, I learned that these can be combined to form a 32bit wide unit, so I just got to have one. Normally, I'd be happy with the 1600, since it doesn't need any external device for dispaly, but the idea to combine two 16bit units for special jobs was too interesting to me. I managed to get myself one - and also the pods for it! - on e-bay. It arrived shortly before the 1600 was done, but now I finally got around to pick up the project! 0:00 Intro / Overview 1:54 Inside! / Display- and Logic Board 3:45 Power Supply / Trimmers / Trigger Switches / BNC 5:20 Front Panel / Delay Dial / Case Frame 6:10 Back Panel / Heat Sink 6:57 Recapping Overview and Example 8:16 Mains Switch / Teardown + Assembly 11:05 Transformer Cleanup / Push Button Cleanup / Probe Pod Sockets 12:43 Delay Dial Cleanup / Potentiometer Knob Problem 14:22 Assembly Time! / Back Panel + Transformer 16:12 PSU Mounting 17:19 PSU Power Up and Voltage Check / PSU Circuit Explanation 18:40 Back Panel Finishing Touches / Case Frame 19:52 Handle / Front Panel Preparation 21:11 Front Panel Mounting 22:09 Power Indicator LED / PCB Cleanup / Front Panel Finishing Touches 23:08 Display Board 24:38 Logic Board 25:25 Power On! / Pods! 26:40 5V Adjustment / Output Signal? / Hunting down The Issue 28:13 Found it! / Fixed it! 29:24 Got Signal! / Got Scope! / Case Lids 30:36 Connecting 1600A? / Trigger Bus / IO Bus 32:05 Final View / Summary / Credits / Outtake HP 1600A restoration video (part 1 of 2): https://www.youtube.com/watch?v=-43Ic0IyNNA Music (in order) My Train's A Comin' - Unicorn Heads (YouTube Audio Library) You can support me on Ko-Fi: https://ko-fi.com/atkelar and also on Patreon: https://www.patreon.com/Atkelar and now also here by using the "Super Thanks" feature! Thanks to everybody who signed up already! ... https://www.youtube.com/watch?v=r1T1eLl0yjc

A day late for April fools... but hey... if you read the discription first, there just was a spoiler ? - A comment about me "rewinding everything with windings" and "soon there will be custom caps" made me thinking: Sure, wax and foil caps are easy enough to make. And some Audiofools might even think those have superior sound. Just like mom used to make them ? I was actually surprised to see that thing at 10nF - but it doesn't stay stable so at the end it was a bit low. It also has about 18M, so it's certailny NOT for actual use... other than novelty! Bees wax makes it smell nice ^^ ... https://www.youtube.com/watch?v=h_9C9rBxJ5U

Workshop #19 - BBC GOERZ UNIGOR A43 In the early 1990s I attempted some higher education... keyword "attempted". I did have some problems with math; somehow the jump between our local school and the technical college was a bit too steep. I did catch up with most of the stuff a few years later, but math was a pivotal subject and I failed almost in all other subjects because of that. But it was my first serious contact with electronics, and the electronics lab there had a bunch of these meters for student use. This is why I do feel kinda nostalgic about it. I didn't write down the model number back then and for the longest time, I tried to find out what they were, so I might get one... and then I binged a few older videos over at @EEVblog and jackpot! This one here had it: https://www.youtube.com/watch?v=S00c_qQB-hA I jumped on ebay and got myself a decent one. Dave's had a "Bauzustand B" sticker on it (i.e. "Revision B") and mine has a "C" revision sticker. Also, his was branded "Metrawatt", mine says "BBC GOERZ" on it. BBC seems to be a rebranding of the origial Metrawatt / Gossen company but I couldn't find info on the "GOERZ" name... When it arrived, I gave it a good wipe down and put it on my desk, since it seemed to work just fine. But when I tried to measure something recently, it was acting up and the needle was jumping all over the place, so I decided to put a bit of effort into it and see if I could fix it! The protection switch wasn't connected; I assume that the students had them disconnected; they probably had something similar to our school going: you trip a breaker, you pay the next soda pop. Either that, or the magnet was too weak even back then and it tripped during normal operation. 0:00 Intro / Presentation / Stuck Case 2:50 Finally Open! / Overview 4:06 Selection Switch and Sockets Disassembly 5:05 Cracked Mirror Replacement 7:07 Contact Cleaning 7:40 Battery Terminals 8:19 Circuit Breaker - Explanation 9:25 C.B. - Disassembly 10:30 C.B. - Rebuild 12:45 Broken Notch Repair / Replacement Battery Switch 13:30 Meter & Switches Assembly 15:00 Sockets Assembly / Reconnecting 16:25 First Measurements / Trimmers 17:10 Final Steps / Closing up Shop / Feature Overview 19:15 Done! / Summary / Outtake Music: My Train's A Comin' Unicorn Heads (YouTube Audio Library) You can support me on Ko-Fi: https://ko-fi.com/atkelar German wikipedia https://de.wikipedia.org/wiki/GMC-Instruments ... https://www.youtube.com/watch?v=23s4yL_0rVQ