Видео 26
Просмотров 52 812

8:53

Focusrite Scarlett 4i4 (3rd gen) - repair notes

7:13

Fluke / Philips PM6680B universal counter/timer repair (x2 !)

8:04

Zoom H4n Pro repair : buttons + SD card door

4:06

HP 1660 (166x/167x) LAN option : DIY add-on

10:59

12V lead-acid charger repair - Mastercraft 011-1517-0

2:10

Reverse engineering: Arturia minilab 3 firmware

I poke around a firmware update file for a USB MIDI controller, the Arturia Minilab 3. The goal of this video is to show some tools and methods I use when first looking at a firmware image.
Some segments have horrible audio for some unknown reason, and the volume is all over the place. My brain can barely handle analyzing firmware while trying to explain, let alone speaking clearly and coherently...
Some chapter markers :
00:00 intro
00:27 firmware update file contents
06:37 identifying instruction set / CPU
07:50 failing at USB-DFU
08:51 ghidra
30:10 teardown
30:30 mcu datasheet
32:23 interrupt / exception vectors
38:17 MIDI and USART
44:27 mem loading address
49:03 Flash surprise code
52:02 MIDI and...

Видео

8:53

Agilent E4402B spectrum analyzer repair

Просмотров 1,3 тыс.4 месяца назад

The E440x series has been well covered by others on YT, but they usually deal with the earlier revisions of the RF deck. Surprisingly the newer revision still fails in the same area (PLL divider), due to another faulty, custom MMIC divider. More details, and PCB files : qcte.ca/testeq/e440x_sa/ Pre-build board from Leo Bodnar : www.leobodnar.com/shop/index.php?main_page=product_info&cPath=125_1...

Focusrite Scarlett 4i4 (3rd gen) - repair notes

7:13

Focusrite Scarlett 4i4 (3rd gen) - repair notes

Просмотров 1,7 тыс.5 месяцев назад

A collection of random notes about repairing the 3rd gen Scarlett 4i4 USB audio interface. TLDR : 3.3v regulator often fails short, sending 5V where it shouldn't (i.e. the CPU). More details on my website, qcte.ca/audio/focusrite_scarlett/

Fluke / Philips PM6680B universal counter/timer repair (x2 !)

8:04

Fluke / Philips PM6680B universal counter/timer repair (x2 !)

Просмотров 9509 месяцев назад

A fairly routine late-90's-gear repair. Two almost identical units; same failure mode. IMO this didn't deserve a 30 minute video and I edited the video accordingly, had to cut out many tedious bits. Hopefully it doesn't make things too confusing. Calibration on these, unlike the PM6681B, does not depend on the RAM backup and does not require special software and equipment to perform.

Zoom H4n Pro repair : buttons + SD card door

4:06

Zoom H4n Pro repair : buttons + SD card door

Просмотров 1,2 тыс.Год назад

Like the previous H4n, suffers from fragile side buttons, fragile SD card door, and a battery cover prone to disappearing. Here I repair two buttons as well as the SD card door. Some extra details and photos : qcte.ca/audio/zoom_h4n/

HP 1660 (166x/167x) LAN option : DIY add-on

10:59

HP 1660 (166x/167x) LAN option : DIY add-on

Просмотров 414Год назад

My HP 1660C logic analyzer didn't have the ethernet option adding LAN capabilities (in particular FTP access and an NFS share). - 00:00 Intro - 02:25 PCB prototype - 04:52 Reflash - 06:28 First boot - 07:20 Disassembly notes Based on information generously published by Jamie Craig here www.jamiecraig.com/hp1661cs-ethernet-interface/ I made a proof-of-concept PCB that adds an RJ45 jack, using th...

12V lead-acid charger repair - Mastercraft 011-1517-0

2:10

12V lead-acid charger repair - Mastercraft 011-1517-0

Просмотров 382Год назад

Despite the claims in the user manual, it contains absolutely no "advanced microprocessor technology". Not a very interesting repair; just a few dead components. A bit of trickery was required for bench testing without a proper battery.

11:03

Meanwell RSP-750 power supply repair

Просмотров 8 тыс.2 года назад

Two defective Meanwell RSP supplies, two different failure modes. Schematics for RSP-1000 can be found online; very similar except for the external control connector (CN51). 00:00 intro 01:02 first psu problem 04:21 PCB bottom side 05:33 second psu problem 07:22 primary side schematics overview 09:46 : second psu test

GW / Instek GPC-3020 mod: automatic fan regulator

9:50

GW / Instek GPC-3020 mod: automatic fan regulator

Просмотров 2372 года назад

A simple, yet overengineered, modification to vary the fan speed according to the internal temperature. By default, the fan runs full blast which is noisy and very annoying. Installing a "fan disable" switch would have been much simpler, but it would be too easy to forget in the "disable" position and risk overheating the supply when running at high power. Index 0:00 intro 0:25 candidate 1: sim...

Excellent fuse design : GW / Instek GPC-3020 (Tektronix PS280/PS283)

0:32

Excellent fuse design : GW / Instek GPC-3020 (Tektronix PS280/PS283)

Просмотров 4102 года назад

Absolutely 0 chance of shorting fuses together.

Canox Starpower / Miller XMT 300 welder: troubleshooting and repair

33:42

Canox Starpower / Miller XMT 300 welder: troubleshooting and repair

Просмотров 2,1 тыс.2 года назад

Troubleshooting and repairing this MIG welder for the second time, after a few months of commercial usage. First repair was "easy", but this time there was much more damage. I also go into a bit of detail on how these work internally and how I went about rigging it for lower power, safe(r) testing. Audio quality is again appalling. Someday I'll learn how to record properly... maybe... 00:00 int...

Artesyn LCM1500 power supply: teardown and modification

4:26

Artesyn LCM1500 power supply: teardown and modification

Просмотров 9132 года назад

Some of these power supplies (like this 48V 1500W model # LCM1500W-T-5-411) come with the negative output terminal internally connected to the chassis ground. Note, the control connector (PMbus) shares the same ground as the negative terminal, regardless of the modification shown here !

4:05

NUM 720 CNC controller monitor repair

Просмотров 7912 года назад

The NUM 720 is a CNC controller from the late 80's . It uses a strange monochrome monitor with unusual signals (TTL, 208-line display, 83Hz Vsync, ~ 17kHz H-sync). I had two of these with unreadable output that looked like a horizontal line, or unreadable text, in the middle of the screen. This lead me to look at the vertical deflection circuitry first. If anyone has further technical informati...

Tektronix TDS744A calibration on the cheap

21:31

Tektronix TDS744A calibration on the cheap

Просмотров 1,7 тыс.2 года назад

A few tips I've found while preparing for, and finally calibrating a TDS 744A oscilloscope. If you don't have time to watch, here are the main takeways: - Supported ISA GPIB cards : www.eevblog.com/forum/testgear/automating-tektronix-field-adjustment-software-for-tds-oscilloscopes/msg1388658/#msg1388658 - CVR calibration does NOT absolutely require a metrology-grade DC calibrator - CVR calibrat...

21:28

HP 8643A signal generator repair

Просмотров 8 тыс.2 года назад

Troubleshooting and repairing this HP 8643A signal generator. Very similar units in the same family include the 8644A, 8644B, 8645A. To a lesser extent also the 8664 and 8665 although those contain a lot more microwave hardware. 00:00 intro 01:40 first power-on 02:18 power section disassembly & tests 04:33 DCU & attenuator cards 07:00 replacement battery 08:31 second power-on & errors 13:03 blo...