Heatsinks are falling off in 6400 and 6600 models.

W8QB

Steve, thank you for that helpful and interesting explanation!

Tom W3FRG

Just a note regarding PEN Option #1.
I just received the rework kit in todays mail. 
It included the T8 Torx tool, two heat sinks, two spare Torx screws and a 5 page detailed instruction pamphlet.


Tom W3FRG

Wayne

Thank you so much for posting this full explanation, I am sorry that you had to divert your time from more pressing issues, however at the same time I feel that if this explanation was posted initially many concerns would have been satisfied and this particular post would not be going on almost 3 pages now along with other posts relating to it.

From your explanation my only question since you had indicated you was the designer is this: The 6600 then has 2 fpga and adc chips while the 6400 has 1 fpga and agc chip supporting the different speeds listed in the brochure, correct?

Something else I wondered for a while where does one go to learn how to program the complex fpga's is it a factory only school or are courses available in colleges.

Thanks so much Gerald for clearing all of this up once and for all.

Kd5spx in Texas.

Robert Lonn

Thanks for explaining this and to Flex for the design enhancement... However ,,,, when I returned from Vacation my mailbox had more Flex Emails about the heat sink then my Spam Folder!! I hope we can finally return to other topics about the Flex Radios and related Software... At Some point in time we should be able to put this to rest...
As a side note, over on the ICOM IC-7610 group as they figure out what to do with heat-sinks falling off, ICOM has already threatened that if you re-attach the heat sink it will VOID your warranty... Flex steps up and fixes the problem, ICOM Threatens its customers!!  Glad I decided back in December to cancel my IC-7610 order with HRO and go with FLEX!!!! 
Robert In San Diego

KY6LA_Howard

It’s actially worse that that. Icom has not yet acknowledged a problem and it’s only through data collection by Adam Farson who is not an Icom employee that anything is even been noticed.

mikeatthebeach .

Icom IC-7610 heatsinks falling off info
http://radioamateur.forumsactifs.com/t2137-icom-ic7610-radiateur-dissipateur-de-chaleur-interne-deco...

Glad I got the Flex6600M instead

Robert Lonn

Wayne,, you hit on an interesting point, programming of the internal Chips....  The reason Flex classifies its software as confidential and propriety is that the software written to operate the radio is complex to get optimum performance.. The Software is KEY to overall performance...

Going back to Collins Radios of past,, the engineers at Collins did more then carefully select the TUBES that would go into the radio,,, but also what they did with everything from the Tube Bias, Plate Voltage and even down to Filament voltage.. Most filament voltage is 6.3 volts,, but Collins ran many at 6.1 volts to add in reliability.. That in turn required the Bias and plate voltages to be tweaked to assure they met their design specification.. Sometimes it is a simple thing that can increase performance, and how much of a compromise a design team takes, can be the night and day difference...  Sort of the Monitor DVI output and a somewhat low resolution taken by others, ,VS the HDMI  Full HD output Flex chose to do... 

I think a lot of Hams think that if something is SDR, then it is all a level playing field and all performance is created equal,, so that means that a $200 radio like the SDRplay will outperform every other radio...  Not that the SDR Play isn't a fun device that gives you exposure to a wide band of frequencies as a receive only device,, but it is no better then the FREE software packages that are available, some with support, most with little or no support..

When ICOM sent out an update for my IC-R8600 radio to allow it to be used with the HDSDR software,, I was able to use my RC-28 external tuning know.. However ever since the latest Windows update, the software no longer works with the radio! So we have been told that ICOM and HDSDR are working on a drivers fix!!! I am not holding my breath for a fast resolution,, After all HDSDR is a FREE software package, so where is the incentive to fix anything? I assume that the fix will be available eventually,, Since ICOM claims they support this package for its radio.. It was nice that Flex had the problem identified and a fix within DAYS of the issue coming up...  Again, you get what you pay for...

Robert

Bill-N6RV

If I understand what is happening using the heat sink improved the dynamic range slightly but the clock sensitivity to temperature is dramatic causing the noise floor to rise several dB when it falls out of sync.

How sensitive is the clock sync to temperature? Will this become a problem a few years down the road when the thermal efficiency of the heat sink degrades?

Again, if it is clock synchronization, I saw a 35 dB increase in noise floor. How much temperature increase would cause a 10 dB increase?

The ambient temperature is also a factor. If the radio is calibrated at an ambient temperature of 70 F how will it perform at the top and bottom of the specified ambient range?

Is the clock sensitivity to temperature an issue?

How big is the chip temperature rise with the heat sink attached versus no heat sink?

For it not to be an issue the temperature rise has to be pretty large and if that is the case then the device is possibly operating at a much higher temperature with no heat sink. If the temperature rise not large then the clock sync thermal sensitivity is pretty high.

Gerald-K5SDR

Dear Bill,

You have no reason to be concerned about the clock alignment with the new heat sink installed or even the original one.  All FLEX-6000s use this same automated clock alignment system since 2013.  Until now, none of them use an external heat sink - only a larger PCB ground plane.  With the new heat sink, they operate cooler than on the older radios.  The thermal adhesive is specifically rated to at 36 pounds of pressure at 100C!!!!  It will be extremely hard to remove once it is fully set.

By the way, the problem with the old heat sink was thermal adhesive quality from the original manufacturer.  The new heat sink is specifically rated for the application. 

Gerald

Bill -VA3WTB

Gerald, is there any benefit to adding heat sinks to the ones in the 6500?

Douglas Maxwell

Is this to do with the interface timing between the ADC the FPGA? If so, when the ADC heats up too much, data cannot be recovered correctly by the FPGA? If so, it sounds like this interface works within a small ambient temperature range and that Flex may have added the heatsink to extend the operational temperature range of the interface before clock to data setup and hold timings are affected? Why else would you put a heatsink on a part that doesn’t require one? Freezer spray anyone? PS. I have a 6300 and a 6500 and both had problems with heatsinks falling off. The danger of one falling off should be enough not to use this methodology again. This lesson was obviously not learnt in the rush to secure more software development funding. When did you last go portable with a 56” plasma screen?

Art - N4QNT

Great explanation, I totally understand now mostly because of the ABS nature of the ic- chip.. thank you

Gerald-K5SDR

Bill,

There is no harm but not a lot of benefit to adding heat sinks to the ADC on the 6500 because it is on an eight layer 10" x 10" PCB with four ground planes.  The 6400 and 6600 use small plug in PCBs with two ground planes so we added the heat sink on those models.  

Gerald

sky

Are next month's (June and beyond) build of 6600's going to have the corrected adhesive fix implemented in their construction?

Gerald-K5SDR

Douglas,

Let me try this once more.  The ADCs on the 6300/6500/6600 are on large PCBs with four ground plane layers and vias from the ADCs.  The 6400/6600 use a new modular design on 1 inch x 1.5 inch 4 layer PCBs with two ground planes.  We added the heat sink to make up for the smaller ground plane area on the PCB.  We went to the modular design for both manufacturing and service reasons.  The original heat sinks were defective from the heat sink manufacturer so they fell of.  The replacement heat sinks are rated at 36 pounds at 100C.  Once they set they are very hard to get off.

We have many many thousands of these exact ADCs and FPGAs operating in the field with exactly the same clock synchronization without issue.  With the new heat sinks the thermal profile is in the correct range and the specs for adhesion are appropriate.  

Gerald

Gerald-K5SDR

sky,
As stated several times here on the Community, everything shipped on or after April 12, 2018 have all of the performance upgrades.
Gerald 

Gerald-K5SDR

Paul, my bad.  ;>)

FYI, the vias are 8 mil diameter and are all covered by solder mask on the bottom of the board so they are hard to see.  They are bare copper on the chip side of the board.

Gerald-K5SDR

Same manufacturer, same chips but much larger PCBs and ground planes. There are no heat sinks on the ADCs on the older models.

Douglas Maxwell

Hi Gerald, If it isn’t to do with interface timings, why does it degrade receiver performance when the heatsink falls off?

Gerald-K5SDR

Steve and I both covered this in earlier posts.  The heat sink helps spurious free dynamic range by a few dB.  Steve provided the datasheet reference in his post.  It does help with timing on the small PCB but not on a large PCBs on the older radios.  This was covered in detail in more than one of my earlier posts on this thread.  Please read back through all the posts Steve and I made in this thread for the detailed responses.  

Bottom line.  With the new heat sinks installed it is a non-issue.  

Gerald

Douglas Maxwell

Hi Gerald, I probably don’t have to understand, but I am a potential customer for the 6600 and at the moment I am concerned with design quality. My understanding so far is that the new small board doesn’t dissipate heat as well as older larger board. As a symptom of this, the interface timing between the ADC and FPGA is affected on the new smaller board over its operational temperature range. The solution is then to add a heatsink to the ADC on new smaller board to better match the old boards PCB stack up thermal profile?

Gerald-K5SDR

Douglas,
Yes, the heat sink on the smaller board replaces the larger PCB from a thermal standpoint.  We measured and compared the different design approaches with a Fluke Thermal Imaging camera.  The measurements show that it meets our thermal and mechanical design criteria.  We could actually change the FPGA code for a wider tolerance range but believe it or not it is less costly to change the heat sinks.  ;>)
Gerald

bahillen

I just replace the heat sinks on my Flex-6600 for the SCUs. It took 45 minutes as suggested in the Installation procedure. It was simple and straight forward. 

What I learned in doing this PEN. 
1. Follow the procedure. By this I mean remove the cover while the radio is powered up. This will allow you to get to the removal of the heat sinks while the glue is still warm that may make the removal a little easier.

2. Note that the vents on the lid are toward the front of the radio. it will make the re-installation of the cover easier so you don't put it on backwards. 

3. My heat sinks were still glued but had moved down and rotated a little. I had the radio on for 24/7 since February. I had to pull on the heat sinks pretty hard to get them to come off. I wiggled them a little but may not be a good idea as the old heat sink may cause a problem with L2 and L3 inductor chips right next to the heat sink.
 
4. I would recommend before you start the Installation that you listen to a couple bands to see signal strengths and noise levels so that when you finish you can listen again as a radio check. I also check one Antenna then switch the antenna to the other port to make sure they were working the same. The band was poor when i did the heat sink installation so I was concerned at first when I put the radio back in service.

5. The installation of the heat sinks is straight forward but if you are a not a handy person you may want to have someone help. It would beat shipping back to Flex for a repair. Study the two cautions and know what parts they are talking about to watch not to damage.

6. The glue on the new heat sinks is good. I mean make sure you have it aligned before putting it down on the board, you get one chance to apply. It wont move. It was a surprise that the new heat sink mount on the non component side of the board so I had to read the instructions a number of times. Study the instructions before you start.

73
Bill
W9JJB

Jim-KB1ZNV

Completed the PEN according to the procedure on my 6600M. The copper sinks were still in place and harder to pull off than I thought even after the over 30 min warmup. Fortunately the boards were very well made so they didn't bend. I had the torx screws removed while it was still warming up so the heat sinks didn't have too much time to cool down. Pretty easy to do but for a minute I worried that I wouldn't be able to pull the heat sinks straight off but all went well.

Tim - W4TME

In response to Jim-KB1ZNV comment about the existing heat sinks being hard to pull off, some of the adhesive used on the heatsinks worked better than others and the chips are still solidly in place even after the 30 minute heat up period. 

If you are concerned about damaging the board or accidentally scraping pff components on the ADC board and you do not want to send your radio into Service to have it installed,  you are not required to remove the existing heatsinks.  Just apply the new heatsinks to the back of the board and take a very small plastic tie wrap or something else non-metallic like twine and install it around the board to hold the copper heatsink in place to prevent it from ever falling off.  It does not need to be tightened very much to hold it place. 

matt_bohl

Where do I find out the serial numbers of affected 6400's or the date of manufacture that this stopped being a problem?

Steve K9ZW

@matt - read this whole thread. The date is mentioned. 73

David Decoons, wo2x

Radios shipeed on or after April 12th have the update. If you have a new radio then you are fine.

Dave wo2x

Tim - W4TME

April 12, 2018

Douglas Maxwell

This will stop being a problem when it’s fixed in firmware.