Hello:
As I wrote around 1 week ago, I had a defective Driver board on my 7K. As I received the new boart from my ICOM dealer, I did the replaceing myself and then discowered that there was no heat compound between the copper strip on the driver board and the heatsink. Even worse is that the copper strip is not flat so only the ends are in touch with the sink. The power dissipation in the driver is 14W independent of the output level (class A). I think the problem must be the missing heat transfer from the transistor via the copper strip to the heatsink.
I would advice to make the copper strip flat before installing it by fileing it with a fine file to be sure the heat transfer is as good as possible and also use heat compound.
73, es LA2NI Kjell
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On Fri, 14 Sep 2007 05:35:39 +0200, John Chandler <jch45975@...> wrote:
Hi Chuck - I was quite concerned to see your post on the driver board etc. Well my friend you "ain't alone" as mine has done exactly the same thing twice. The last trip back to Icom Australia from the selling dealer resulted in them contacting Japan for assistance. I heard 2nd hand that an earth loop mod corrected the problem and I have had the 7k back in use now for about a week with no drama so far. The first time it went up in flames and filled the shack with nasty smoke. In fact the dealer smelt the 7K in it'[s box as I took it through his door. The 2nd demise (after 3days back) saw no smoke and flames but a distinct phtttttt was heard. The driver FET is used for HF, VHF and UHF. Apart from those probs which were fixed under W/Ty I guess I was content with the rig!!!!!! BTW., the rig still smells slightly so I hope that may disappear. Hats off to the local dealer UHF Comms. here in Townsville for their W/Ty service on boh occasions. This 7K was one of three purchase!
d in November 2006. Perhaps you could pass on this info to your repairer just in case.
Good luck mate...
Dave ... VK4DCC Townsville North Queensland.
----- Original Message -----
From: Chuck
To: ic7000@...
Sent: Friday, September 14, 2007 8:40 AM
Subject: [IC-7000] Re: Driver Board is smoked
Mine went up in smoke today while on 6 Meters!!!!!!
Not too pleased right now!!!!!!
I'll be sending my IC-7000 back after only about 18 months of service.
It was an early production radio so I guess the driver board issue had
not been addressed at that point.
What sucks is I wanted to try to work 3B7C on some other bands this
week and now I'm toast. By the time I get it back, they will be
finished with the DXpedition :( :( :( :(
Maybe time to buy that TS-2000 or PRO III I have been wanting(?)
****If ICOM won't help with the repair issue, I won't be buying any
more of their products again!!!!!!!!!!
We SHALL see............
73,
Chuck Pyatt KB3MMX
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--- In ic7000@..., "n7xq" <moonman@...> wrote:
>
> I beleive that the DRIVER UNIT ( Mosfet PD55015 ) went up in smoke on
> me, I had just made several ssb contacts and decided to give CW a
try ,
> that lasted about 5 min. then a small ball of smoke rolled out of the
> top of the rig and All RF output, on All Bands and All modes stopped,
> no output at all, The recieve is excellent on All Bands and All
modes .
>
> I will call Icom tomorrow and try to find out if this is a common
> problem and if there is a fix for the Issue that Icom will provide.
>
> The Serial # of my Rig is 0503212. Has anyone else had this problem
> that wouldn't mind shareing there experience?
>
> 73
> Craig N7XQ
>
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