The BLF GT70 "Giggle Monster" is here! 7,500lumens, 1,500m throw! Group buy Closed!

2802 posts / 0 new
Last post
Texas_Ace
Texas_Ace's picture
Offline
Last seen: 39 min 20 sec ago
Joined: 03/24/2016 - 07:44
Posts: 8376
Location: Everything is brighter in Texas

Replacing the driver is not hard at all, just 2 wires if they solder the switch on for you at the factory.

hank
hank's picture
Online
Last seen: 20 sec ago
Joined: 09/04/2011 - 21:52
Posts: 8084
Location: Berkeley, California

Automotive alternators can generate extremely high brief voltage spikes when you are starting the engine. I’ve seen warnings to either filter the DC or turn off LED lights before cranking, to avoid killing them.

This may be like the recommendation to bang two sticks together to keep the elephants away, I dunno. Lemme see what the Internet advises.

Quote:

… As Kevin said, anything intended for automotive use will have this taken into account. These systems may be commonly described as “12V” to the public, but it’s well known the voltage will be higher.

Designing electronics for automotive “12V” power can be a challenge. The fact that the battery charging voltage, and therefore the running voltage most of the time will be up to nearly 15V is no big deal. The electronics does have to be designed for a wide enough average voltage range, like 9-15 Volts if you want it to operate over most conditions.

The much tougher part is that spikes of 10s of volts can happen regularly. For example, you might be tempted to use a ordinary 7805 regulator to make a low current 5V supply from automotive 12V power, but it might not last very long. There are special regulators specifically designed to tolerate the high voltage spikes.

Another issue is that even the 14.3V you measure may only be a average over 100s of ms….

https://electronics.stackexchange.com/questions/15444/can-an-alternator-...

scr79423
Offline
Last seen: 1 month 2 days ago
Joined: 04/29/2018 - 15:12
Posts: 160
Location: Bangkok, Thailand

i must have gotten a good FET in my GT70, i even bypassed all my springs with 20AWG and running murata vtc5A flat tops, the light is still going strong

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

Update on the conversation with lumintop. After a while of back and forth emails with them they are going to send me a new driver. For $20… Just waiting by the mail box now. As I’ll now have a spare driver that only requires a FET replacement, can anyone point me to what FET I should be looking for? I figure there’s no loss if I kill it now so I may as well try fixing it.

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

ThembaFatsani wrote:
Update on the conversation with lumintop. After a while of back and forth emails with them they are going to send me a new driver. For $20… Just waiting by the mail box now. As I’ll now have a spare driver that only requires a FET replacement, can anyone point me to what FET I should be looking for? I figure there’s no loss if I kill it now so I may as well try fixing it.

I can’t remember what the driver looks like, but with most of TA’s FET drivers he uses this style FET.
http://www.mtnelectronics.com/index.php?route=product/product&path=25_76...

There’s a few really good MOSFET models out there like the Infineon BSC009NE2LS5IATMA1, for instance. I’m not sure what’s available near you, though. The genuine ones can’t usually be bought from China. Hopefully some Australians can point you in the right direction where to buy some good ones. They are cheap so you can buy several as extras.

Texas_Ace
Texas_Ace's picture
Offline
Last seen: 39 min 20 sec ago
Joined: 03/24/2016 - 07:44
Posts: 8376
Location: Everything is brighter in Texas

Yeah, there are a lot of FET’s out there that will work just fine. The Sir800 / Sir404 are good options. the BSC009NE2LS5IATMA1 is better but harder to find.

In a pinch these should work as well:

PSMN1R7-25YLDX
PSMN1R5-30YLC

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

Thanks so much for the info lads. I’m really grateful you are here and helping a newb such as myself. Hopefully my next update has the GT all repaired.

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

So Lumintop are being quite slow with the replacement driver. I’m not sure when it will be here. I did however receive the new fets in the mail along with some solder paste, and some braid for solder removal. I watched some youtube, did some reading, and practiced for a while on an old video card removing and replacing small surface mount components. I found it was basically impossible for me to move anything larger than about 2mm without hot air. And my hot air gun is better suited to melting poly pipes for plumbing than microscopic circuit board components.

Nevertheless I thought it would be worth a go, and I thought I had a reasonable chance of success. It was time to have a go at the GT itself. Quite a daunting task for a total noob such as me. I was as precise and careful as my fat fingers would allow and in the end it looked kind of ok… put it all back together and…… same exact issue. The light fires up fine, and on ramp it just reaches the same dim level it did before the fet swap.

Anyone have any other ideas? Did I roast the fet, or install it wrong? Can I check it with a multimeter? Sorry to be a pest I’m just at a loss of what else to do.


 


before:
https://drive.google.com/open?id=0ByQSXXcbJReWcno0WFhDSmVnRTBsbzNZVjA5Um...
after:
!https://drive.google.com/file/d/0ByQSXXcbJReWdUR1Zm5sU0NIR0lGdHcxZ01CdnN... https://drive.google.com/file/d/0ByQSXXcbJReWSW1YM2FuN1dFSjJFOEVQekw1NkM... https://drive.google.com/file/d/0ByQSXXcbJReWS043S0RLZk1fTE0zWFZ5c2xBRTZ...!
ready to turn on again …
https://drive.google.com/open?id=0ByQSXXcbJReWYUNYT2J1eVQ2RWw3Q2d5LVYxLV...
JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

It doesn’t look too bad. I usually take my iron and go along the sides if the FET to remove any excess solder. It looks like all 4 of the small feet got soldered.

I’m not sure why that didn’t fix it. I use leaded solder for its lower temps and only get the components hot enough to melt the solder. No extra heat is desirable.

Maybe the driver is not putting out a proper signal to the FET. It’s the FETs that are most sensitive, though so they tend to be the first thing that goes bad.

Texas_Ace
Texas_Ace's picture
Offline
Last seen: 39 min 20 sec ago
Joined: 03/24/2016 - 07:44
Posts: 8376
Location: Everything is brighter in Texas

In the last picture it looks like there is a broken trace where the MCU mounts, that particular pin doesn’t go to the FET IIRC but if one pin is bad it is not a strech to think another might be. It could very well be something in the path to the FET that is the issue.

If you have a bench power supply there are some tests you could run but without it you would need some way of providing power to the driver while it is out of the light.

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

hmmm. I don’t have a bench power supply. I guess this repair was a bit too much for me Sad back to waiting by the mailbox.

lawallac
lawallac's picture
Offline
Last seen: 1 hour 45 min ago
Joined: 01/04/2012 - 15:31
Posts: 416
Location: WI
Texas_Ace wrote:
In the last picture it looks like there is a broken trace where the MCU mounts

Is there something wrong on this component or is this an artifact of the photo or a piece of black thread?

Texas_Ace
Texas_Ace's picture
Offline
Last seen: 39 min 20 sec ago
Joined: 03/24/2016 - 07:44
Posts: 8376
Location: Everything is brighter in Texas
lawallac wrote:
Texas_Ace wrote:
In the last picture it looks like there is a broken trace where the MCU mounts

Is there something wrong on this component or is this an artifact of the photo or a piece of black thread?
!{width:75%}https://lh3.googleusercontent.com/6ZFfOtQtqkRFKT7302U821WpUzWNrQ6giPFAk4...!

Yes, that is what I was referring to. That particular pin should not cause the issues he is having IIRC but if one pin has an issue it is possible others do as well.

raccoon city
raccoon city's picture
Offline
Last seen: 2 hours 20 min ago
Joined: 10/06/2010 - 02:35
Posts: 12674
Location: रॅकून सिटी Palm Desert CA USA

@lawallac:

I cannot see your photo.

lawallac
lawallac's picture
Offline
Last seen: 1 hour 45 min ago
Joined: 01/04/2012 - 15:31
Posts: 416
Location: WI

Ok tried to relink it with sharing.

raccoon city
raccoon city's picture
Offline
Last seen: 2 hours 20 min ago
Joined: 10/06/2010 - 02:35
Posts: 12674
Location: रॅकून सिटी Palm Desert CA USA

Now I see it.  :THUMBS-UP:

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

I think I’m going crazy.

The replacement driver (finally) arrived today and I was very keen to swap it in. All the hard work of pulling the light apart was already done so it was a very quick job, just a couple of wires and it was ready to go.

To my dismay it behaved exactly as it did beforehand. Blinks on when batteries are in as expected, then in ramp mode it just stops at about 10% power and then blinks again about 3 seconds in to the ramp. Double click only reaches the same low power mode.

When it was suggested that I could replace the FET and it would fix it, I ordered a few FET’s and a spare xhp70 12v emitter as well. So having a spare XHP70 I thought perhaps it’s just the emitter. I popped in the new emitter and …. full blast activated! for about 1/2 a second. then it was back to low power.

Again , it would ramp to about 10% and never get brighter. Something different about the mtnelectronics xhp70 was that it only lights 2 of the 4 sections of the die in moon mode, then 3 , then all 4 as it gets a little brighter. quite odd.

Have I just got a magic touch and am destroying these parts as I touch them? Could it be my batteries? Does the driver sense any weakness in the batteries and refuse to go full power? Please guys- any suggestion is welcome at this stage I’m at my wits end.

Again, sorry for being such a newbie.

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

It’s kind of normal if moon mode only lights a few dies. As long as all 4 come on just above Moon mode. The driver provides a really tiny amount of power at it’s lowest so the dies just barely light up.

Are you using 4 or 8 batteries?

What voltage does it blink out after 3 fast clicks?

Make sure the battery tube is fully tight to the head first, then tighten the tail.

Man, I don’t know what to think.

You didn’t accidentally get the drivers mixed up and put the old one back in, did you?

Is the aluminum shelf the driver sits on nice and clean?

All screws in the battery carrier tight?

One more thing, your using unprotected batteries, right?

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

When I first had problems I checked the voltage of each cell, checked the voltage of each carrier, with a multimeter and with the voyage test mode of the light. Over 16 volts from memory. No cell was out by any notable amount.

I have since got the short tube and tried to use 4 cells. Same problem.

I’m sure I didn’t mix up the drivers. The whole thing is spotless, brand new. Connections are clean as.

I’m starting to lean towards the batteries being the problem. They are unprotected, they were flat tops and I soldered a blob on the top of each of them to make them button tops. I guess they are the problem…. what else could it be?

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

One of the solder blobs may be just tall enough to touch, but not touch strongly. Maybe the jolt of high amperage causes the connection to break.

I’ve seen this happen on high powered lights where the tail cap or head wasn’t getting a good connection to the battery tube or the battery ends or spring ends were dirty.

lawallac
lawallac's picture
Offline
Last seen: 1 hour 45 min ago
Joined: 01/04/2012 - 15:31
Posts: 416
Location: WI

I don’t suppose your charger shows internal resistance? I’d wondering if maybe the batteries got damaged when you were doing your solder blobs. You do have to be pretty quick and deliberate because it can quickly damage the cells. It certainly wouldn’t hurt having 4 or 8 good ones as backup. What cells are you running anyway? Thanks.

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

Using some “Panasonic-Sanyo NCR18650GA 3500mAh” …. care of eBay …

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2F...

Being that I’m having issues I’m starting to question there legitimacy…

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

That ad looks correct.

Did you check that your solder blobs are sized so that it has the right width and height? You might have to shine a light in there to check the gaps.

You want to see a tiny air gap all around the shoulder of the battery and on the sides of the solder blob. That way you know the spring is pushing the solder blob into the terminal with force.

Texas_Ace
Texas_Ace's picture
Offline
Last seen: 39 min 20 sec ago
Joined: 03/24/2016 - 07:44
Posts: 8376
Location: Everything is brighter in Texas

Well since the new driver does the same thing, it sounds like the issue is the LED and your test seems to prove that. The strange part is that it happened again.

A bad reflow could cause this but that would not explain he first LED.

Have you checked under the mcpcb, cleaned it very well and made sure it is flat and there is nothing that would prevent a good flat contact with the shelf. You then need to replace the thermal paste with fresh paste when reinstalling.

Overheating the LED could cause something like this but then so could over current.

The next step would be to replace the LED again I am sad to say. You could contact lumintop for a replacement or buy your own which will be a bit higher quality most likely.

This time don’t go into turbo though, only go to the top of the ramp and see what happens. This will prevent it from getting too much current and help figure out the cause.

If I had to guess though the LED overheated. I have had this happen before we started using DTP mcpcb’s and you gave an LED too much current or if the mcpcb does not have good contact with the shelf.

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

Thanks for all the input fellas. Had me very confused and annoyed for a while there.

Due to doubting the 18650’s I have I grabbed a spare 3s LIPO which was sitting about 11.9v , not a full charge but has massive discharge ability. I soldered it up to the old driver I removed from the light (the one with the replacement FET). I again tried to fire up the replacement XHP70 and again it only achieved a very low level of light. This suggested to me the batteries are not the issue, and made me question again the LED as you suggested Texas_Ace.

So I dug around in the spare parts box and came up with a spare 12v MT-G2 just lying around. I wired it up to the driver on the bench, added a heat sink, plugged in the 3s LIPO (around 12v) and …. boom. Ramping mode goes up and up and up way past the dim brightness achieved on my XHP70’s.

I think this is finally solved… I should have listened to you from the beginning Texas_Ace. It also makes sense to me now with the relacement LED going super bright for a fraction of a second and then reverting to super dim mode. I really didn’t think it would have overheated and fried in that fraction of a second. I’ll have to chalk it up to experience.

I guess I’ll have to speak to Lumintop and try to get another emitter. They were so slow getting me the driver I’m really not looking forward to waiting another 2 months for a replacement emitter…

I hope my next update is with a new emitter and the light finally working again.

Thanks again everyone for your input. Hopefully the headaches are now over.

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

ThembaFatsani, what type of emitters did you get from MTN? Xhp70.2 and not xhp70, right?

Was it already mounted to a mcpcb? I didn’t think MTN had boards large enough for the GT. Did you buy just the emitter and reflow it yourself?

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

Texas_Ace wrote:

Overheating the LED could cause something like this, but then so could over current.

Wow, I didn’t know this. I’m gonna have to add it to my mental troubleshooting list.

So too much heat or current (only on 70.2 or other leds?) can cause it to function normally, but only up to a certain brightness level, then it just stops there?

What do you think causes this?

ThembaFatsani
ThembaFatsani's picture
Offline
Last seen: 5 days 19 hours ago
Joined: 10/25/2018 - 03:41
Posts: 33
Location: Australia, Western NSW.

I got this one http://www.mtnelectronics.com/index.php?route=product/product&path=60_11...

Already on an MCPCB. I just squashed it down into the thermal paste left after removing the original MCPCB and emitter, I didn’t screw it down. Which would explain why it died in a fraction of a second of full blast.

Having had a little practice reflowing that FET, now I’m thinking I’m probably able to reflow my own LED’s now.

Not a skill I was planning on acquiring but I guess it will be useful … haha. I’m an idiot.

Pic of the LED itself https://imgur.com/i4SYQle

JasonWW
JasonWW's picture
Offline
Last seen: 1 hour 26 min ago
Joined: 10/22/2016 - 11:41
Posts: 10924
Location: Houston Texas

ThembaFatsani wrote:

Already on an MCPCB. I just squashed it down into the thermal paste left after removing the original MCPCB and emitter, I didn’t screw it down. Which would explain why it died in a fraction of a second of full blast.

Oh, so you didn’t have any pressure pushing the mcpcb onto the flashlight shelf. Yeah, it won’t last long like that. Normally the reflector/centering ring presses it down nice and uniform around the led.

The screws are for anti-rotation. They might work decent for heat transfer, but I wouldn’t trust full power to them. Not with a FET driver and a 70.2.

Over heating explains the 2nd led going bad. I wonder why the first one went bad? Maybe it’s reflow onto the mcpcb was not so good. The middle pad of the xhp70/70.2 is just for heat transfer. If they didn’t have enough solder there it may not have transferred the heat quick enough.

Reflowing the emitter is not too hard. You just need something to hold the mcpcb while you blow the hot air up from the bottom. I hold the hot air gun between my legs and hold the mcpcb with some pliers. I raise and lower the mcpcb to change the temperature. My free hand can use tweezers to remove the led.

Then I use my solder iron to remove the old solder and apply new solder. Then you heat it up again over a minute or two with the new led sitting on top of the solder and a dab of extra flux. This will preheat the new led slowly avoiding thermal shock. Once the solder goes liquid I make sure it’s centered and push it down so any excess solder comes out the sides. Then remove from heat and let it solidify.

Nev
Offline
Last seen: 28 min 55 sec ago
Joined: 04/06/2017 - 07:50
Posts: 715
Location: U.K.

ThembaFatsani wrote:
Thanks for all the input fellas. Had me very confused and annoyed for a while there.

Due to doubting the 18650’s I have I grabbed a spare 3s LIPO which was sitting about 11.9v , not a full charge but has massive discharge ability. I soldered it up to the old driver I removed from the light (the one with the replacement FET). I again tried to fire up the replacement XHP70 and again it only achieved a very low level of light. This suggested to me the batteries are not the issue, and made me question again the LED as you suggested Texas_Ace.

So I dug around in the spare parts box and came up with a spare 12v MT-G2 just lying around. I wired it up to the driver on the bench, added a heat sink, plugged in the 3s LIPO (around 12v) and …. boom. Ramping mode goes up and up and up way past the dim brightness achieved on my XHP70’s.

I think this is finally solved… I should have listened to you from the beginning Texas_Ace. It also makes sense to me now with the relacement LED going super bright for a fraction of a second and then reverting to super dim mode. I really didn’t think it would have overheated and fried in that fraction of a second. I’ll have to chalk it up to experience.

I guess I’ll have to speak to Lumintop and try to get another emitter. They were so slow getting me the driver I’m really not looking forward to waiting another 2 months for a replacement emitter…

I hope my next update is with a new emitter and the light finally working again.

Thanks again everyone for your input. Hopefully the headaches are now over.


It would have been much quicker & a lot less work to send it back for a refund & buy a new one Tired

Pages