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eHam Forums => Elmers => Topic started by: W4AJF on February 10, 2013, 08:29:01 AM



Title: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: W4AJF on February 10, 2013, 08:29:01 AM
Hi all, I bought a Non working TS-940SAT. It was working but over time the TX, RX, and display went out. It power up, meter light comes on, RF Gain with move the meter full scale, when you hit the AUTO/THRU button the TUNE light lights up (no tuning though), NOTCH button will light up NOTCH light but not much else happens. It is 100% complete, my question is, these are known for cold solder joints, can anyone tell me if I had to pick a board to try to re flow the solder, which one would be the most likely?  It is a 70 million serial number. If I can not get anything going will sell as is or for parts but would like to take a shot at it. YES, CPU has been reset and no change.

Thanks for any help.

Adam Farber W4AJF
Woodland Hills, CA
adamf@eeco.com


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: K2DC on February 10, 2013, 08:53:46 AM
Adam,

   That sounds like a problem I had with a TS-440SAT.  No TX, no RX and the display was all dots (or dashes, i forget).  The problem was that the PLL was unlocked.  I had to send it to Kenwood for a component level repair.  Not sure if that's your problem, especially if the display is comepletely blank, but that was my issue.

GL & 73,

Don, K2DC


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: WN2C on February 10, 2013, 10:16:15 AM
Adam, go to Kenwoods site and look at service bulletin 900. 

Rick  wn2c


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: KA4POL on February 10, 2013, 10:20:50 AM
See uder http://forums.qrz.com/showthread.php?299982-TS-940S-No-Tx-Rx-OK and follow the links. There is a lot of information.


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: W4AJF on February 10, 2013, 12:14:04 PM
Thanks to all who answered. None are exactly what I have, I believe in the Service bulletin 900 for the PLL unlock, the LED display is blank but still lit up, mine does not even have that so I think it's something else. If anyone knows more specifically what may cause this or what board I can take a shot at please let me know.

Thanks,

Adam Farber W4AJF


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: KE3WD on February 10, 2013, 01:45:10 PM
Sounds to me like a low voltage power issue and not a PLL at all. 

Get the Service Manual first, do a websearch for a free .pdf of the manual for it. 

Then check all the DC powerlines for proper voltage, likely you will find one that is either not up to snuff or not there at all.  Follow it back to the regulator and check for bad component(s) there.


73


Title: RE: Help with Kenwood TS-940SAT, no TX, RX, display.
Post by: W4AJF on February 10, 2013, 01:49:51 PM
Yes, that does make sense but may be a tad beyond my skill level but will look in to it. Thanks!

Adam Farber W4AJF