Flex 6xxx Fan Replacement

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  • Updated 11 months ago
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There has been great concern about fan failure and replacement in the fgpa fan speed thread.  That thread has gotten almost impossibly long and difficult to follow.  

The concern of late has been about acquiring fans and DIY replacement.  K2CB has been kind enough acquire fans at a favorable price so acquisition is not a problem.  Replacement is the next hurdle.

 The concern expressed by Flex re DIY fan replacement is the concern about damaging the chip due to the fact that the adhesive is so STRONG.
The other concern expressed by Steve is difficulty replacing the shroud.  It doesn't look too difficult so long as you are extremely careful getting all the tabs aligned properly.

I hope someone (Flex?) will post detailed instructions.  Meanwhile my  4 year old 6500 has been been cruising along with no problems but, in an abundance of caution I have ordered 2 spares.

Hopefully,  Steve will post a failure rate of these fans so we will have an idea how real the concern about fan failure really is.
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Gene - K3GC

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Posted 2 years ago

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G8ZPX

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Gene and all,

I have done the fan replacement recently (I posted original fan pics). They are not at all difficult to change, you should leave the heatsink in place (no need to disturb the heatsink bonding anyway).

Carefully unscrew the fan subassembly from the heatsink whilst holding the heatsink so that it does not try to rotate, then place the new donor fan to the existing heatsink. Check they spin-up okay, and the radio boots happily with the new fans - job done.

The RF cage is pretty large, but NOT difficult to get back on. It has lots of friction grip fingers, and is hampered some by less than idea positioning of it close to the outer case, but it can be done.

The whole job takes about 30 mins and is easy to do - provided you have good eyes and a steady hand. However, it should only be attempted by those that understand which end of a soldering iron gets hot (!) i.e. if you already do component level work then this is a walk in the park. Not sure why Flex make out its such a big deal really.

The only bad thing is that Flex have failed to take a positive lead with good service - especially when the fan are failing so prematurely. The user base has had to ID the problem, find the part code, find a source, and order parts for themselves. A sad reflection on Flex IMHO.

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Gene - K3GC

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Thank you very much - that is exactly what I was looking for.  Now if Flex will only publish a realistic failure rate.
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Michael Coslo

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Considering that this might very well have been a bad batch of fans, it would be pretty difficult to come up with a realistic failure rate for everyone. 
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Paul Bradbeer

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Thanks.  I'd be happy to do my own fan replacement to my 6500 if it needed it...it sounds like you've found a UK supplier.  I feel like I should buy a fan and it keep it just in case.  Please could you let me know how you got yours?  Regards  Paul M0CVX

p.s.  I'm in Lincoln...so not far away from you I guess...

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Steve - N5AC, VP Engineering / CTO

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In Austin, Texas right now, we have been told by officials that there is no gasoline shortage.  My car was at 7/8 full yesterday and I didn't think twice as I passed several stations with long lines.  As a result of everyone discussing the "gas shortage" many people have run into the streets to fill their cars and large containers with gasoline.  I saw one picture yesterday of someone filling a huge trashcan with gasoline.  I bet you can guess what I think of that.   The average gas gauge reading in Austin is probably the highest it has ever been.  With the panic now firmly in place, many stations around Austin are without gasoline.  As a person with an education, I looked at the numbers on refineries that were down, where the gas comes from and the percentages and I decided that I was not concerned.  Certainly not "fill a trashcan with gas" concerned.  No doubt, the people that staged a run on the gasoline stations are saying "I told you so" -- and they probably believe they are right and they feel justified.

There's an old movie with Robert Redford, Sneakers, where the antagonist makes the comment that mentioning publicly that a bank is unstable causes a run on the bank and the run on the bank causes it to be unstable -- even if it was fine to start with.  Panic begets panic.

Yes, some of the fans are failing earlier than we expected.  We believe something that has changed with the supplier as the early fans we purchased are having significantly fewer problems that newer fans.  We had an internal discussion about fans long before anyone pointed out publicly that there have been fan failures.  We are investigating and working toward a solution.  Our ME passed away suddenly this year and we have someone to help us now, but we had a backlog of work for him and this hasn't been addressed yet.  We will formulate a solution and we will communicate about it when we have it.  

We (FlexRadio) will continue to charge some of the lowest service rates in the industry, treat our customers fairly and do all we can to help them.  As we have time, we will continue to answer well-intentioned, sincere questions from you guys -- our loyal customers -- on anything that is of interest to you that remotely concerns our products or ham radio.  I appreciate that some of you are concerned because of a component failure.  Please believe we're doing all we can to get to the crux of the problem and come up with a solution, but continuing to suggest that we might not do something about it (and what a disaster that would be for FlexRadio) just isn't helping.  Someone suggested that we are not "providing facts" on actual MTBF of the fans.  As an engineer, if I'm asked to report MTBF you sorta have to know the time that the fans are running. We do not collect information from our customers on how many hours a day their radios are turned on, hence the calculation is difficult.  It helps no-one for me to get into a pedantic discussion about calculation of MTBF.  It also really doesn't matter -- MTBF is a decision support tool.  We've already made the decision that we are not pleased with the fan performance and want a replacement solution.  Why would I painstakingly calculate MTBF now?  All the answer I need as a businessman is "the reliability has decreased with the newer fans and we would like a replacement solution."  Please give us the time to develop a solution.  And don't panic.
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K2CB Eric Dobrowansky

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Manufacturer and part number?
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Tim - W4TME, Customer Experience Manager

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Since it is not a user serviceable part, we do not provide that information publicly.
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Rich - N5ZC

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Tim,

When did the new replacement chip cooler start?  I sent my 6700 back in late October for an update. 

Thanks

Rich - N5ZC
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Tim - W4TME, Customer Experience Manager

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We still have an inventory of the original part that we are using up before transitioning over to the new one.
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Rich - N5ZC

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R,R
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Steve - N5AC, VP Engineering / CTO

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Official Response
As you may be aware, the original fans used on the CPU and FPGA parts inside of the shield in the FLEX-63/65/6700 radios have been failing prematurely.  After investigation, we believe that these fans will continue to fail over time in the field (it is not a lot problem).  So while they could be replaced with the same model fans, they will all have a similar MTTF to the existing fan, which includes premature failure.  If you have already or plan to replace your existing fans with the same manufacturer fans, you are likely to experience the same failure rate as the original fans in approximately the same time-frame since it is the same fan from the same manufacturer.
We have a ordered a custom fan from another manufacturer to replace the originally selected fans.  The fans are currently in production and we will let everyone know when they are available.  At that time, we will transition to only replacing fans with the new ones.  These are a higher cost, single-piece fan/heatsink assemblies and so the old heatsink/fan must be removed from the IC before the new one can be applied.  Improperly removing the old heatsink can result in a damaged IC and/or a damaged PCB, both of which require substantial cost to remedy.  While we would prefer to have a field-installable option, we were unfortunately unable to find one.  Your radio will need to be returned to FlexRadio for this service, if required.

We will post here again when the new fans are available.  For most of you, I would not recommend prophylactically replacing the existing fan if it has not failed.  If you plan to be in an area that is remote and replacing the fan would cause an unusual inconvenience, however, you may want to replace the fan before it fails.  This is an individual decision based on your tolerance for being without your radio when it needs to be serviced.

To simplify the service, if you have just a fan issue or need just the fan replaced, we will replace both CPU and FPGA fans, check out your radio and return for a fixed cost of an hour of bench time (currently 99USD).  We always perform a test on customer radios when they arrive in the shop and if other issues are found, we will contact you with any other issues that are found and the cost to repair, if applicable.  This fee is for an out-of-warranty radio.  If your radio is in-warranty and has a fan error message, the repair and return shipping fall under our warranty policy.  

For completeness, please note that we are not aware of any issues in the side fans of any of the FLEX-6000 radios and these fans do not need to be replaced.  The new FLEX-6400 and FLEX-6600 radios no longer use individual IC fans, instead using a single larger, slower moving fan along with mechanisms to ensure all parts receive air.
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Tim - W4TME, Customer Experience Manager

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Since there is no one around the radio and probably won't be for a couple of months and since I can't get to it, how can I tell remotely whether my fans are going or gone? I don't want my radio to be damaged due to excess heat; which might be a little difficult perhaps under these conditions.

The firmware will shut down if the FPGA and/or CPU are not being cooled sufficiently and before any damage can occur.
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L.Kubis

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Thanks Tim -- will I know at the control point (computer or Maestro) why the radio shut down?

Lloyd
VE3ERQ
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Tim - W4TME, Customer Experience Manager

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The client will receive an error message along with a disconnect message.
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Steve - N5AC, VP Engineering / CTO

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Lloyd, we monitor three things in the 6500: both fan speeds (CPU, FPGA) and the FPGA temperature.  If either fan fails or if the FPGA gets too hot, the supervisor in the radio will remove power from the radio and allow it to cool (protecting the radio).
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L.Kubis

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Thanks Steve and Tim, at least I know the rig will survive safely. I just hope I don't have this happen, at least for several months.

Lloyd
VE3ERQ