[Yaesu] FT1000MP overheating and audio failure

[Robert Shohet]

Hi Dave,

Thank you for your reply and information!

I had that same question about the fan.  It felt like there was some “draw” through the top of the vents on the right radio but no draw on the left – of course that could have been because the heat energy overwhelmed the “draw” from the fan.  I will check the fan on the left radio – thank you for that suggestion – that is something obvious that I can check!

I have had great repair experiences with Byron – plus several times he told me what to do so that I would not have to ship him my radio – saving me both money and repair time!

Let’s talk about your spares directly - off the reflector.

Tnx & 73


Bob 



From: David Robbins 
Sent: Monday, May 28, 2018 3:15 PM
To: 'Robert Shohet' ; yaesu at contesting.com 
Subject: RE: [Yaesu] FT1000MP overheating and audio failure

Was the fan coming on?  That could have failed causing runaway overheating of the power supply which would cause it to shutoff, I think there is a thermal switch in there somewhere.  could also be bias voltage on the final transistors causing them to draw current on rx when they shouldn't, also causing overheating and runaway.   Eventually it probably blew the internal fuse.  I would recommend you buy one of my spares and ship that one to wa4geg for repair...  http://hamradiobug.com/   In case you haven't dealt with him before, be sure you email for appointment and follow his packing instructions... he may be picky on shipping but his repair work is excellent.


David Robbins K1TTT
e-mail: mailto:k1ttt at arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net:7373



-----Original Message-----
From: Yaesu [mailto:yaesu-bounces at contesting.com] On Behalf Of Robert Shohet
Sent: Monday, May 28, 2018 18:57
To: yaesu at contesting.com
Subject: [Yaesu] FT1000MP overheating and audio failure

Hi,

While operating the WPXCW contest this weekend, on Friday night my left FT1000MP began to become warmer than the right radio.  Since I have some antenna controllers partially blocking some of the vents on the top of the chassis, I didn’t think much of it until the radio did not seem to want to cool off after I moved the controllers away from the vents.  I thought that this was odd since I wasn’t transmitting with the left radio – and by contrast, the right radio was cool even though I was transmitting on it almost continuously.

Then, all of a sudden, the left radio shut off by itself!  I pushed the on button and it would not turn on.  Then after ~15 minutes, I was able to turn it back on.  But it stayed very warm.  Hmmm...  This annoying process repeated more and more frequently on Saturday morning – turning itself off and then having to wait about 15 minutes before I was able to turn it back on.  Finally, the radio failed and when I turned it back on, there was NO audio and the swr was infinite!

Realizing that there could be many potential failure points, I took the coax from the left radio and hooked it up to the right radio and everything was fine – swr was low, the left amp worked at full power and everything was normal.

Then I took the coax from the right radio and plugged it into the left radio and the swr was infinite with NO audio.

Clearly the left radio had the failure not the amp or coaxial cables.

Does anyone know what might have failed and what needs to be fixed?

Tnx & 73

Bob, KQ2M 

kq2m at kq2m.com
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