Thurlby Thandar... not a happy bunny - Page 1
Forum section: electronics / general

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 07, 2012, 04:30:44 pm
content: My voltcraft VLP series 60V power supply has just died (and since i did not have time neither intention to fix it) i ordered a TTI PL601 bench supply from farnell. I was hesitating on getting a tektronix one (for nearly the same price), but i liked the TTI one better (due to its features and rotary knobs). The supply arrived in a day (as everything from farnell), but when i opened the box and took the thing out, something was terribly rattling in it. I managed to get the thing(s) out via the air vents by rotating and shaking the supply (i did not open it for warranty reasons). A clip for the heatsink came out in two pieces. It looks like it was on a rectifier lookalike package, which still has one clip left on it, BUT it is also cracked. Before you would ask, no there is no damage on the packaging, not even a small dent.I went for TTI, because i thought it was something high quality. I am definitely not a happy bunny!What would you do? Would you send it back under warranty, or would you request two of these clips from TTI and fix it by yourself?

author: Zad
author_rank: Super Contributor
timestamp: September 07, 2012, 04:40:43 pm
content: To be honest, metal fatigue in a component like that is just not something you test for when building equipment. That clip will have had a fault in since the original steel was rolled, exacerbated when the clip was fitted, and then failed at some time after that. You can only go so far in testing supplied components.I would drop TTI an email, asking them if repairing it would invalidate the warranty, and if not then could they please send a clip.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 07, 2012, 04:47:05 pm
content: Quote from: Zad on September 07, 2012, 04:40:43 pmYes, i just did exactly the same thing. Since it is friday late afternoon here, i guess i will have to wait until monday for their answer.... but two damaged clips in the same unit

author: Rufus
author_rank: Super Contributor
timestamp: September 07, 2012, 05:32:52 pm
content: Quote from: Baliszoft on September 07, 2012, 04:30:44 pmI would have got Farnell to replace it next day and collect the faulty one.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: September 07, 2012, 05:54:00 pm
content: Quote from: Baliszoft on September 07, 2012, 04:30:44 pmDefinitely warranty, quite likely something else is causing these clips to crack, perhaps something under the semiconductors such that the clips get much more tension. That would mean you cannot trust the rest of the thermal system either... No need to solve their problems, as a matter of fact, if they take quality seriously, they will want to investigate themselves anyway.

author: saturation
author_rank: Super Contributor
timestamp: September 07, 2012, 06:14:06 pm
content: As its brand new and TTi supplies are not cheap, I'd contact Farnell for a replacement ASAP. There was a TTi teardown somewhere and it shows it uses what appears to be Avid clips:http://www.aavid.com/product-group/maxclips/searchI'd also send email to Avid and see what they say.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 07, 2012, 09:28:22 pm
content: I will wait for the answer of TTI. To be the honest i really had enough of returns, i had to return an agilent mso some months ago.If you got a product, just send it to me, i guarantee that it will fail some way.

author: MikeO
author_rank: Contributor
timestamp: September 08, 2012, 12:41:37 am
content: Quote from: Zad on September 07, 2012, 04:40:43 pmI think Zad has it right. That doesn't look like a fatigue failure, it appears shattered. Low quality steel, nitrogen embrittlement problem in plating, or maybe failure to temper, and maybe an installation press out of tune. Throw in some rough handling from shipping, and it fails. I'd say you should assume all the clips are bad, from a bad lot, and act accordingly.Most of all, treat your vendor as your partner: what should _we_ do to get me up, and, what is the best defensive strategy to prevent the remainder from failing? Do you need this back for failure analysis?Please excuse me for being so emphatic, but on this, I feel so strongly...Keep in mind, customer service folks get nothing but abuse. Pretty much every caller is angry and looking for a victim to abuse and berate. Don't be that guy. Be the guy that brightens their day; make them excited to help you. If they support you very well, send them an email noting that, thanking them, and acknowledging that you know that even 100% inspection will not result in 100% quality, and though you wish it hadn't been your number that came up, the experience on how it was handled has made you a more loyal customer. If it went well, and you shared that positive experience on this forum, tell them so. Link it. That not only makes the guy or girl helping you feel good, that gives them collateral to send to their manager, and gives the manager something to brag about to his or her manager. The next time you need help, you contact that agent directly: you'll be the number one priority to them from that point on.It's all about achieving your goal. In these situations, my goal is to be up and running as soon as possible, and an increase in confidence in the equipment. I think that most callers to a customer service department think that is their goal, but their words and actions convince me that their real goal is to vent their frustrations.My mother used to say, "you can't modify the behavior of an adult. You cannot force them to do anything. You could hold a pistol to their head, and they might decide to die. People will only do what you want if they want to. What are you doing to make them want to do what you want?"Try to make this an opportunity Balizsoft. Connect with a human and make them a partner in your success. Change your self-perception of 'every product I get fails in some way,' to "no one gets a product fixed faster than me. No one gets better service. No one gets loaners from them, no one but me that is."All just my opinion, but also, my experience, from having tried both approaches, and also, my experience running the departments that supported the men and women that answered those phones. They are just people, bruised, battered, tired people, who know, tomorrow brings more just like today.Regards,Mike O'

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 12, 2012, 12:11:49 pm
content: Update:At first i have contacted TTI about the problem (sent them these photos). They answered on the next workday, that i could either send it back to farnell, or to them and they will replace it, or i could just fix it by myself if i want (without losing the warranty). I chose the latter, so they are now sending me new clips. Will take some photos when they arrive.

author: G7PSK
author_rank: Super Contributor
timestamp: September 15, 2012, 04:19:55 pm
content: The clips have been over hardened or failed to go through annealing after the quench from the first heat or it there are a lot of them all the same the metal was the wrong specification to begin with. I used to use clips for holding cables to chassis by the thousand and at one point had a batch that failed with just about every one due to the wrong heat treatment.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 17, 2012, 04:41:52 pm
content: I have received the replacement clips today, so i opened the unit up and took some photos. They sent me 12 new clips, the power supply contains 6 of them, but only two were damaged. I have checked the other four which seemed to be OK, so i have replaced the ones which have fallen out. The new clips seem to be different (less shiny) from the old ones.I did some fast measurements with no load, and the output seems to be spot on. Okay, the multimeter has got a higher resolution than the voltage display on the unit, but still the accuracy is exceptional (probably better than the accuracy of my meter).The feature which i actually like in this power supply is the voltage span option. You can set the lowest and highest value for the pot, so you will have got a very high resolution in a certain voltage span. By default it is set to 3->5 volts (for the full 300 deg of the pot) and setting 4 volts this way (this is a 60V unit) is still accurate.I could do some overshoot tests if you are interested.

author: SeanB
author_rank: Super Contributor
timestamp: September 17, 2012, 05:30:19 pm
content: Samwha caps.......... I hope you replaced all the clips instead of only the broken ones, as it is very likely this is a batch issue and the rest will fail sooner or later.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 17, 2012, 05:35:49 pm
content: Quote from: SeanB on September 17, 2012, 05:30:19 pmNo, only the failed ones. They are holding strong (yet).

author: SeanB
author_rank: Super Contributor
timestamp: September 17, 2012, 06:00:59 pm
content: Twang.................SMOOOOOOOOOOOOOOOOOOOOOKE!!!!!!!!!!

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 17, 2012, 07:01:33 pm
content: OK. will replace them later

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 17, 2012, 09:23:53 pm
content: All clips have been replaced. I had to take the "power" board out for this, also remove heatsink (to loose all the clips at once) from the board. Took a pic of the devices mounted on the heatshink. Also did some load tests.

author: paulbt
author_rank: Regular Contributor
timestamp: February 11, 2020, 10:29:46 am
content: Hello guys !Thank you for the pictures from the inside of this unit! I have recently bought from TME an identical unit like yours (PL601) and I am very pleased by it's size, design, features, quietness and panel meter's accuracy. It is indeed expensive, but I can really tell it is robust and well built compared to other much cheaper linear power supplies I own. I have also registered on their website for extended 3 year warranty., which is a nice thing to have.Do you still own this power supply? What other issues did you encountered in the last few years?

author: unknownparticle
author_rank: Frequent Contributor
timestamp: February 11, 2020, 04:03:49 pm
content: I was given a TTi psu that was faulty and had a missing knob. I tried to find a replacement knob but it was obviously unique to TTi, so I called and asked if I could buy one. I had a conversation with a technical guy and I happened to mention it had a fault and needed a couple of components to repair it. He asked me which they were and said he would include them with the knob, all FOC!!! He sent 3 knobs and 2 off each of the components, all of which arrived the next day! This was on a unit well out of warranty and which I didn't even buy! I've never had better customer service and have subsequently bought 2 further items of TTi test gear, not new but had it not been for that experience TTi wouldn't even have been on my radar for test gear, as I didn't even know much about the company previously. So, I can do nothing but recommend TTi very highly.My unit also uses that type of clip, slightly different as they are brightly, or were brightly, nickel plated. They are now quite rusty, so the unti has obviously seen some damp conditions. I am not a fan of these heat sink clips, I prefer old school nuts and bolts, I think the main reason they are popular is manufacturing speed and convenience.

author: wraper
author_rank: Unknown
timestamp: February 11, 2020, 04:27:35 pm
content: Quote from: unknownparticle on February 11, 2020, 04:03:49 pmWhich are way worse. They cause way more deforming stress on package. Also on bottom side of component (where BTW heat is produced) often remains gap which obviously results in inferior heat transfer. With clip you have part pressed in the middle which ensures component sitting flat on a heatsink. Not to say clip is way better for insulation as you don't need to have any holes in thermal pad and creepage distance is way higher.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: February 11, 2020, 05:09:20 pm
content: Thats what heatsink compound is for! I've never had a problem with nuts and bolts, even in some very high dissipation applications.

author: wraper
author_rank: Unknown
timestamp: February 11, 2020, 05:51:56 pm
content: Quote from: unknownparticle on February 11, 2020, 05:09:20 pmWhen there is something like 0.2-0.3 mm gap, thermal paste sucks at transferring heat.

author: Gyro
author_rank: Super Contributor
timestamp: February 11, 2020, 09:07:43 pm
content: Interesting through-board (SMD) mounting of the metal-clad current sense resistor. Saves on mounting screws.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: February 12, 2020, 04:51:32 pm
content: Quote from: wraper on February 11, 2020, 05:51:56 pmAs I said, never had a problem with thermal compound, nuts and bolts. Clips and sil pads are for manufacturing economy. If a clip breaks, and they do, you may not realise until the magic smoke appears!

author: wraper
author_rank: Unknown
timestamp: February 12, 2020, 05:19:07 pm
content: Quote from: unknownparticle on February 12, 2020, 04:51:32 pmHave you actually measured component temperature to claim "no problems". Sil pads, are for insulation, not manufacturing. Sil pads are used with screws and clips are used with thermal paste. There is no exclusivity of use.QuoteAlso I guess you never seen insulation pad electrical breakdown around mounting screw. Especially when mica with thermal paste is used (better heat transfer) instead of sil pad.

author: voltsandjolts
author_rank: Unknown
timestamp: February 12, 2020, 05:35:17 pm
content: It seems that Thurlby Thandar (TTi) were helpful and responsive to this fault and your enquiry.I think it would be fair to them to perhaps update the title of this thread"Thurlby Thandar...not a happy bunnyhappier bunny now"(No affiliation...just a happy customer of TTi)

author: wraper
author_rank: Unknown
timestamp: January 20, 2022, 09:13:27 pm
content: Digging the grave but... Was packing my equipment because I'm moving to another place. Heard strange rattle in my PL303QMD. Sure enough one of the clips was broken. Decided to remove one from rectifier and use as a spare because it had 2 of them unlike other parts. It cracked during removal but did not break apart right away. Removed another one on the same rectifier and put in the middle of it. Then decided to remove one from rectifier in another channel, it simply disintegrated on the lightest touch. Barely touched another clips with tweezers, they simply fell apart with no force applied. In the end I have 2 good clips and 10 broken. Will check another a bit newer PL303QMD at the new place since it's already packed.

author: rsjsouza
author_rank: Super Contributor
timestamp: January 20, 2022, 10:26:29 pm
content: POS supplier of parts, not technology or method.

author: wraper
author_rank: Unknown
timestamp: January 21, 2022, 08:31:15 am
content: Quote from: rsjsouza on January 20, 2022, 10:26:29 pmThey are very thick and stiff compared to other clamps I've seen. And IMHO they were over-tensioned. If they were not inserted into the groove that deep, probably they would be fine.

author: Huluvu
author_rank: Regular Contributor
timestamp: January 21, 2022, 11:37:08 am
content: I bet this is caused by hydrogen embrittlement due to the galvanisation process ....The manufacturer of the clips scimped on the relaxation process during galvanisaion ( which takes time and money)This causes hydrogen to be trapped under the zinc plating in the hardened steel structure and will sooner or later make them brittle. Sometimes they gas out and the clips survive or it takes just longer ( can be many months)