Electronic component for Epilog Laser tube Circuite board

[Ivica Vasic]

Hello everyone!
I have Epilog LAser Helix 40w for 10 years... I had problems before which some of them I have solved with the help of this forum so I ask for your help once more!

The thing is my Epilog has stopped working in 2013 and after a detailed search on the internet I have found this forum and on one of the threads was the solution to my problem!
The customer support and main distributors in my country have been adviced me to just get the repaired tube from Epilog and pay more than 4000$ and lose the whole month to get one because I live in Serbia!
But I have found that if u take the tube out and get it to some experienced electrician that he will make tube work again..s it was the case with me.

The broken part was this one :
The 300w 50v VHF POWER MOSFET
388684


and now again the same part broke but i cant find it anywhere except AliExpress!

So, does anyone knows or have someone who can find this part or knows where I can find it..... except the AliExpress of course!

Thank you in advance!


P.S. If your Epilog does "ran outa CO2" find some good electrician that knows the stuff and check it with me... it saved me 4k $ !!

[Jamie Buxton]

I don't know anything about lasers, but googling with BLF278 gives a hit. (Mouser is a respectable electronics parts supplier in the US.) https://www.mouser.com/Search/Refine.aspx?Keyword=BLF278

And https://www.rfparts.com/rftransistors/transistors-blf/blf278-nxp.html Somewhat lower price.

[Ivica Vasic]

I don't know anything about lasers, but googling with BLF278 gives a hit. (Mouser is a respectable electronics parts supplier in the US.) https://www.mouser.com/Search/Refine.aspx?Keyword=BLF278

And https://www.rfparts.com/rftransistors/transistors-blf/blf278-nxp.html Somewhat lower price.

The thing is mouser in Europe is diferent .. these guys here will refunt amount for the part i purchase but they wouldnt refund a custom duties! They even said that they will left that amount (which is about 110$ ) for my next purchase on mouser.com but i dont hink ill buy anything form them.

The part was defect and he did not give full power..
For example instead of 290 w or so it gave 30w on output!

:( first time i bought form them and it was bad :(

[Paul F Franklin]

Digikey lists the BLF278 as being obsolete and discontinued, but lists a microsemi VRF1516G-ND as a direct replacement, and they have them in stock. Digikey is a big distributor here in the states, I've bought thousands of dollars of parts from them with no issues, for what it's worth.

Keep in mind that if the FET keeps failing, there may some other problem with the board.

[Ivica Vasic]

Digikey lists the BLF278 as being obsolete and discontinued, but lists a microsemi VRF1516G-ND as a direct replacement, and they have them in stock. Digikey is a big distributor here in the states, I've bought thousands of dollars of parts from them with no issues, for what it's worth.

Keep in mind that if the FET keeps failing, there may some other problem with the board.

Thank you for the fast reply!

I will tell the to repairguy that u have warned me about the board!

Anyway i tried to search but I tried and cannot find that part on Digikey site...
I tried a search by the manufacturer also but no results!

Can u copy link or something or i have to call them?

Thnak you

[Paul F Franklin]

Not sure why search doesn't find it! Here is link:

https://www.digikey.com/product-detail/en/microsemi-corporation/VRF151G/VRF151G-ND/2053300

[Ivica Vasic]

Because number 6 instead of G... lol u put VRF1516 instead of VRF151G
Now is ok! So I can replace BLF278 with VRF151G without any worries??? :)
:)

[Paul F Franklin]

Oops, sorry. All I can say is Digikey says it's a direct replacement, and all the important specs seem to match. There is always some risk in substituting parts, but this seems straightforward.

[Ivica Vasic]

It's ok! Thank you for the advice! :) I'm shure gonna talk to my electrician and consider this! :)