Got a TS-940S and I am experiencing intermitant problems, sometimes when it is first switched on there are no lights or LED's but if you turn the tuning dial, it all lights up but not as it should, the lights, frequency and LED's, come on but are very eratic, i.e. frequency display does not read correctly and it sometime goes into transmit without the mic being keyed for a short period, then it appears to settle down and is normal again, had a few QSO's with excellent reports but wondered if anyone else has had similar experiences.
This is a great radio, and was a long time DX contester favorite, but does requrie a bit of TLC.
There are a handful of top Kenwood service technicians -- that will repair these for handicapped amateurs -- or those with no techncial/repair backgrounds.
Jeff King ZL4AI / DU7 has assembled all of the service / repair notes for this fine radio.
THE HUGE ADVANTAGE IS YOU CAN STILL SERVICE THE Kenwood TS-940 Radio !!
Remember the only reason most 940 owners ever sell, is their radio has now developed faults, and they cannot bear the large cost of getting another person to repair the radio. So sadly they replace it with a radio that is working, for economic reasons. Most say if it had not developed faults I will still be using it because its performance is as good as all the latest models.
Almost all radios after 1991 have been made using surface mount technology. The components are very small and difficult to work on. For many amateurs servicing these radios is difficult, and requires soldering equipment with good temperature control, very fine tips and electrostatic safe.
The TS-940, (and others of the very early 1990s like the Icom 765, and Yaesu FT-1000D) can still be serviced, and most parts are still readily available at local stores.
You can use standard off the shelf equivalent capacitors, resistors, ICs and often equivalent replacement transistors. The cost of these parts is low and they are readily easily available.
The only parts hard to get are ICs specially programmed by Kenwood [Only a few of these in the 940]
You can buy second hand TS-940 boards on EBay and elsewhere at very reasonable prices.
With second hand boards and parts you can still obtain every component. Don’t sell your TS-940… Repair it.
If you like kits (or previously assembled Heath-kit radios), then you could say the TS-940 is like one large kit set, preassembled.
The Yahoo Group: Amateur Repairs --
currently has a current discussion on TS-940 repairs.
This radio has a large number of plug/connectors from the PC boards to the wiring harness. Over the years these connections can become intermittent.
In addition, the TS-940 AVR board (voltage regulation for circuits within the radio) .. can become problematic (failed components, resistors opening, capacitors drying out). Remember that this radio (1980s vintage) is over 20 years now......
Last edited by W9GB; 02-03-2009 at 02:24 PM.
That helpful reply wasn't much use to someone living in Scotland ! I believe there is a TS 940 group on Yahoo, have a look on Google and you will probably find it. If you do need to have a repair or service job, I know its a long way from your home but Castle Electronics near Welshpool is a very fine radio engineer.
I would not insult a Scotsman with such a statement
That helpful reply wasn't much use to someone living in Scotland !
The answer applies to any TS-940 owner!
Jeff King, ZL4AI is from the South Island of New Zealand ..
TS-940 Group on Yahoo Groups -- 220 members
Kenwood Communications UK, has the following network of Amateur Radio Repair Agents in the UK.
Waters & Stanton
22 Main Road Hockley
Tel: 01702 206835
Fax: 01702 205843
Tel no: 01938 810778
Unit 1 Fitzherbert Spur
Tel: 02392 313090
Fax: 02392 313091
Martin Lynch & Sons
Tel: 0845 2300 599
Fax: 01932 567 222
NEED SPECIFIC PARTS IN UK ???
Acoustic Services LTD
66 Place Farm Way
Tel no: 01844 347600
Opening hours: Monday to Friday 9.00 to 6.30
Last edited by W9GB; 02-03-2009 at 02:48 AM.
I acquired a 940 abt 9 yrs ago with a similar problem. To my recollection, all I did was pull the multi pin connectors (very carefully) in the digital unit, very sparingly applied some caig cramolin blue or gold, and re-seated them. The unit has worked w/o trouble ever since. The previous owner was a smoker and that may have attributed to the problem but in my experience these type(s) of connectors and their plating become problematic. At least this is a simple procedure that at worst, if all goes well, will only take up a little time. Take your time and keep track of everything.
Thanks for all your replies, I will try the fix that KX2E mentioned to see if this works Ok, if not I will try all the others. I will let you know how i get on.
Any other advice is also welcome.
TS 940 S cannot transmit SSB
I just got a TS 940 S from my cousin SK , no problem in CW, but in SSB I cannot transmit, have you an idea WHY ?
Last edited by 3A2MD; 03-08-2009 at 09:54 PM.
Same suggestion for you, go to the Yahoo 940 group and they will be able to give you advice.
Re my comment about being not helpful to someone in Scotland. Its no use giving people US information if they live 3,000 miles away !
No Kenwood support for TS-940s anymore
My 10 year old (I bought it new) Kenwood TS-940s went "south" this morning. It stopped transmitting in the middle of a DX contact and I knew by the familiar "smell" that something had cooked! Sure enough, when I removed the RF output board cover, I saw transistor Q2 was burned. I called Kenwood East and Kenwood West to try to see if I could send it to them to get it repaired. They both said that they did not support the radio anymore and didn't have parts for it and couldn't repair it. I could probably repair it myself if I can find the parts. I couldn't asked for a better radio but I think Kenwood's repair policy stinks! I will try to find a third party repair shop to repair it if I can't. I'd rather someone familiar with the radio repair it, and preferably a Kenwood repair center. But it "ain't gonna happen". I've always been a "Kenwood man" but will think twice about buying anything else from them and I suggest you do the same!
The radio is over 20 years old. You will not find many Detroit Big 3 auto manufacturers supplying adequate repair services for an automobile that old -- these days!
I couldn't asked for a better radio but I think Kenwood's repair policy stinks! I will try to find a third party repair shop to repair it if I can't. I'd rather someone familiar with the radio repair it, and preferably a Kenwood repair center. But it "ain't gonna happen".
Some of the parts used in this radio are no longer available from OEM mfg. (obsolescence)
I would suggest a phone call to Clif Holland at Avvid [since you are in the USA].
John at LPC Wireless is another option (I have not used his services)
The Automatic Voltage Regulation (AVR) board is a KNOWN Problem with this radio.
This is covered in the earlier links from Jeff King, ZL4AI
When it fails -- it takes out these expensive RF power transistors.
Section 2 of his extensive repair notes:
Kenwood can not control their suppliers (and neither can Yaesu, Icom, Motorola, etc.).
I've always been a "Kenwood man" but will think twice about buying anything else from them and I suggest you do the same!
For example, the later TS-850 is another great radio --- BUT the Japanese mfg. of 2 highly integrated ICs is stopping production of that specific part!! It happens far more often than you are likely aware -- sometimes in the middle of a popular production run -- hence Rev B or Rev 2 comes out -- or the model stops after the factory parts inventory is exhausted!
Your statement just shows a lack of knowledge -- that this has been the current operational
constraints for the last 15 years. You stop vertical integration approaches (where you make all the parts) to save money (but raise your dependence and risk!) -- you are then dependent on these other OEM mfg. for your overall production of the system/unit.
Kenwood has been quite GOOD at giving dealers, distributors and amateurs
advance notice of these End of Life (EOL) / Service announcements -- whenever it can.
Last edited by W9GB; 01-13-2010 at 09:37 PM.
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