Kenwood TS-440SAT IC-10 Upgrade Gone Wrong

Discussion in 'Radio Circuits, Repair & Performance' started by AC5ZU, Oct 21, 2010.

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  1. AC5ZU

    AC5ZU Guest

    I intended to modify my old 440SAT with a couple of IC chips (IC-10 Interface Kit) that would enable computer rig control capability via ACC1. Got the chips in the mail, read the instructions in the owners manual, and start pulling the covers and face apart to get access to the logic board behind the control panel. Made sure I was grounded, then popped the chips in, closed everything back up (being careful not to pinch any of the myriad wire bundles in there) and powered up.

    I was greeted with no receiver noise or control capability and a VFO display of all '8s'.

    Opened everything back up and reinspected my work. Saw that one of the chips (the CMOS divider) I thought I had put in was only half in. One entire row of pins on one side of the chip missed the IC socket. I pulled the chip back out and reseated it.

    Before closing up this time, I powered the rig up and got a new but equally disturbing result. Still no receiver noise, but now the VFO display is garbled and strobing rapidly.

    Maybe the chips were bad? I pulled them out; no change.

    So has anyone seen this in a 440? Is there some simple error I made when I opened up the unit? Is it worth spending the money to get it fixed? Does Kenwood even still repair these old rigs?

    Any suggestions would be appreciated.

    Dennis Wofford
  2. W9GB

    W9GB Ham Member QRZ Page

    Dennis -

    These 2 integrated circuits: IC54 - uPD8251AC (NEC) and IC55 - TC4040BP (Toshiba)
    provide a serial connection to the uProcessor used in the TS-440SAT.

    Your TS-440S Operator's Manual provide the proper instructions on page 29 -- 6-3 Interface TC Kit IC-10 Installation

    Kenwood stopped providing service support for this radio when some
    component parts (from their suppliers) became unavailable.
    BTW, this radio and its technology components are almost 30 years old !

    The TS-440S is a great starter radio -- I have one here that I cleaned and updated in 2005 from a silent key estate. I have the service and operating manuals (that I acquired when I worked on this radio in 2005) -- so it was fairly easy for me to look this up.
    That mistake was on radio's uProcessor control board (ugh) ... Patience is a required skill with radio repairs!

    Contact Clif Holland, KA5IPF at Avvid in Mabank, TX, who specializes in Kenwood radios of this vintage,
    he may be able to help you with your radio.

    There are Yahoo groups dedicated to the TS-440S and Amateur Repairs,
    I have contributed to both (files section).

    Last edited: Oct 22, 2010
  3. M0DCD

    M0DCD Ham Member QRZ Page

    Bin the 4040 and try again, BTW I used an 82c51 and that worked fine.
  4. K9ASE

    K9ASE XML Subscriber QRZ Page

    I also have a 440 it's my starter radio and I love it.:) I just wonder do they make a DSP add on for it?
  5. AC5ZU

    AC5ZU Guest


    Well, after chatting with one of the local hams about my situation, he suggested I do a MPU (main processor) reset. Found the procedure in the manual. It was brain dead easy; hold down A=B function button while turning the rig on. Shazam! Everything is working beautifully. Got the serial to USB interface working through ACC1 and the IC-10 chips are now letting me get full rig control (okay, as much as the 440S will do, anyway) through Ham Radio Deluxe.

    Although I found this solution outside this forum, it's always good to have a repository of such knowledge that QRZ offers. It's saved my bacon in the past on other areas, for sure.

    Thanks for everyone's willingness to help!

  6. W9GB

    W9GB Ham Member QRZ Page

    Dennis -

    Glad to hear that you resolved your issue. I thought you already preformed the uProcessor reset ? -- glad that the uProcessor reset did the trick (other options were ugly).

    BTW, while you had the radio open did you check the lithium coin cell battery for leakage? Even though mine worked, it had started to leak -- which required clean-up of the electrolyte paste (acid)

    Not as an Internal option (DSP chips for audio and radio usage came about 10 years AFTER the TS-440 was designed in late 1970s/early 1980s).

    You could purchase an external audio based DSP, if you desired.

    Radios with Intermediate Frequency (IF) based DSP designs have only been available since ~ 2000 (e.g. Icom 756Pro).

  7. K9ASE

    K9ASE XML Subscriber QRZ Page

    That's what I thought. I had a CB in the 90's that had DSP. I'll have to check the TS-440 Yahoo group for what the best external option might be.
  8. WA9SVD

    WA9SVD Ham Member QRZ Page

    If the MPU reset didn't work, I would have suggested replacing the 4040 chip. At least THAT is an inexpensive COMS logic chip. (The 8251 chip is obsolete and is getting difficult to find.) Plugging the chip in with half the pins improperly terminated and connected could have damaged the chip; apparently it didn't. But it's something to double check every time.
  9. KI6ZIF

    KI6ZIF Ham Member QRZ Page

    The last time I read a set of instructions on the IC-10 install, It specifically said to do a reset after installing the chips.
  10. KJ4VPI

    KJ4VPI Ham Member QRZ Page

    In my case, the Divider and the UART chips went in smoothly enough, but there was no RXD / TXD to or from the radio. That was confirmed with an O'scope. Probing around, I determined that the chip designed to work in conjunction with the crystal wasn't providing a clock. No clock, no UART operation. That one chip was soldered in, so either the rig was manufactured with a bad part, or something caused it to go bad during it's use prior to coming into my care.

    Having the proper equipment to diagnose an issue is important. But you've got to have the proper tools to fix the problem you find too. In my case, desoldering tool, angle cutters, a good kelly clamp, magnifying glass and strong lighting. Specially the last two.

    I strongly agree, this is a great starter radio... I'm learning a lot with it and having a good deal of fun.
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