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Thanks Bob

I fixed 2 ICOM 7000 with PD50015 burnt ; compliments for your job and thanks for your feedback

Best 73 de IW0HEX Pasquale

(Rome, ITALY)

Il 23/07/2024 19:34, Bob ha scritto:

Hi all, I've attached a picture of the burned and new driver boards. There is a 1 ohm resistor on both. I hope the picture isn't

too large for groupsIO.

Bob W4JFA

On Tue, Jul 23, 2024 at 1:00?PM Paul Hansen via <pwhansen=[email protected]> wrote:

Congratulations on successfully replacing the driver board in your IC-7000. Replacing those flex cables from the PA to the MAIN is a real challenge.

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Now for the reason I’m jumping in on this. The driver is not being
damaged from excessive heat. No IC-7000’s have any heatsink compound under the metal substrate. Those driver transistors and the circuit they are in seem to be barely stable. I believe they are breaking into an oscillation and setting themselves on fire. Many IC-7000’s have come through here with a smoked driver. Almost all of them melted down while in receive. Several smoked without ever transmitting at all.

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The 1 ohm resistor place in the source lead is designed to provide a bit of negative feedback in hopes of halting oscillation. It’s partially successful. I’ve repaired and replaced drivers that have been updated too.

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Thank You

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Paul W. Hansen, W6XA

Amateur Radio Service

2134 Carthage Road

Tucker, GA 30084

(864) 222-3539

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From: [email protected] [mailto:[email protected]] On Behalf Of Bob
Sent: Monday, July 22, 2024 19:57
To: [email protected]
Subject: Re: [ic7000] Driver board

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Got it done. Full power out on all bands. Old board burned. There was no heat sink grease on it. It looks like the heat sink design is good but why would they apply grease on everything else but not that?

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Years ago I replaced an RF brick in an Icom dual band mobile, IC207. No heat sink grease on that either. It does now. I don't get it.

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Yes the radio gets quite warm. Did very little transmitting and still warm. A while back I worked on a friend's 706. I was on the air testing and talking to a friend and noticed it was getting quite warm. My friend that I was talking to owns about three 706's. He said that's normal. That made me feel better cuzz I was getting concerned.

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Thanks guys. I would like to be a 7000 owner someday

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73, Bob W4JFA (near Charlotte, NC)

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On Mon, Jul 22, 2024, 7:41 AM RICHARD OLSON via <richard777=[email protected]> wrote:

Hi Bob

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The 7000 notoriously runs hot. I have had mine for over 10 years and like a Timex watch it takes a licking and keeps on ticking. I keep a small fan blowing from the back on the heat sink towards the front.?

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Richard w3rlo

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On 07/21/2024 9:13 PM EDT Bob <w4jfabob@...> wrote:

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Geoff, Thank you. I'll start on the radio Monday USA eastern time. I don't know if the new board has the resistor or not but maybe I can add one if it doesn't. If the added resistor is the only change then I'm sure there's no reason why I can't add one. I've done things like that B4. My gut feeling is if I can add more heat sinking, that will help. Not sure until I see it.?

I'll?keep you posted.

Bob W4JFA?

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On Sun, Jul 21, 2024, 6:33 PM Geoff via <vk3zgw=[email protected]> wrote:

Hi Bob,

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The driver pcb is not too difficult to get out and you will see the signs if it was the cause of the smoke. If your new driver board has the new resistor fitted you're good to go. But you will have to go through the adjustment procedure contained in the manual. I've replaced 2 and they're still working fine

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Take pictures before the disassembly, it really helps.

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73

Geoff

VK3ZGW

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