Mike - You can view the Schematic diagrams (6 pages) for the Elecraft KIO3B module. https://ftp.elecraft.com/K3S/Manuals%20Downloads/E740323%20K3s%20Schematic%20Files.pdf The KIO3B is a multi-function module, that includes these functions: 1. RF Board interface 2. Digital I/O interface 3. Audio I/O interface 4. USB, Codec, RS232 FTDI FT232R (USB), TI PCM2901 (CODEC), TUSB2036 (2/3 port USB hub) 5. Digital I/O 6. Audio I/O == It is NOT impossible to repair or troubleshoot (component-level), BUT it can be time consuming for the novice or weekend technician. This is why Elecraft stated “economical” (their bench time is NOT Free). — Sage advice from my high school electronics instructor, WB9FUR (sk, 2016) has served me well : External event (ESD, Over-voltage, Op error) and I/O ports are major causes of module or circuit failures. Electronic devices rarely “die” for no reason (assumes QA production of part). — “What functionality” has failed will narrow the circuit areas and components to examine. IF you can “think thru” those observed symptoms, many failures can be pinpointed with a DVM to a few key components. SMT repair experience and tools reduces repair time. — This summer, I repaired an ESE ES-188 Master Clock ... that the reseller suspected was not working properly. Visual and operations inspection: * Not damage to tinned copper foil traces on PC board. * Bulging 25V electrolytic caps (85° import brand) on DC filtering - replaced (105°) * Multi-serial TTL level ports from microprocessor were inconsistent - replaced MAX233 (resolved one port) - replaced 74LS04 and 74LS08 (resolved other ports)
I did not even pull out my DVM ... the secondary DC ripple was eliminated, and an external event (ESD?) likely entered thru serial port ... damaged the 3 ICs replaced. Those 3 parts were closest to DC power bus and serial port entrance to PC board. It’s been running on the bench, driving NTP and IRIG-B remote clock for past 3 months ... no issues. IF I were to resell, I would check with DVM & possibly scope. greg, w9gb === Date: Thu, 29 Oct 2020 17:43:44 -0400 From: K4PI <k...@bellsouth.net> To: Elecraft Mail Reflector Subject: [Elecraft] KIO3B Main Board Repair I have ended up with 2 bad KI03B boards E850645. Both bad in the USB circuit. I did some basic checks resistance wise they recommended, but found no problems. Elecraft said chances of repair was slim and would not be economical to try. I think all the other functions are okay (think they are still working okay if you come in via the serial port). Seems a shame to toss them into the dumpster, but unless someone has had some experience of repairing them that may be the route. Anyone ever attempted at repair of the USB circuit on these?? 73 Mike K4PI ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
