[Solved] Help identify this transistor - Page 1
Forum section: electronics / repair

author: spilihps
author_rank: Regular Contributor
timestamp: December 28, 2019, 06:34:21 pm
content: Hello!Currently trying to diagnose a control board for a AC unit.Found a transistor marked 6060V5 that is short between all it's legs.However my Google skills ain't good enough to find a datasheet or compatible replacement!Any idea?Thanks!

author: wraper
author_rank: Unknown
timestamp: December 28, 2019, 06:44:23 pm
content: Seem to be IGBT according to various sources, some say MOSFET. You can order exact part from China though.One source says:Quote

author: wraper
author_rank: Unknown
timestamp: December 28, 2019, 06:52:39 pm
content: Apparently can be replaced with something like thishttps://www.mouser.com/datasheet/2/149/FGH60N60SFD-962300.pdf

author: spilihps
author_rank: Regular Contributor
timestamp: December 28, 2019, 08:32:18 pm
content: Thank you!Yes IGBT seams about right since the legs is marked with ECG?Would you thinkhttps://www.electrokit.com/uploads/productfile/40324/FGH80N60FD.pdfwould be OK?They don't have 60N60 on hand, and this is a little bit of a time sensitive project..These are the IGBT that I can receive quickly:https://www.electrokit.com/produkt-kategori/transistorer/igbt/(Sorry swedish only)Then of course it is the matter of what may have caused this, and if something else broke or did cause this to fail. Will probe around a bit more on the board..

author: wraper
author_rank: Unknown
timestamp: December 28, 2019, 08:42:43 pm
content: QuoteI guess it should be fine. Not that we know exact specs of original anyway.QuoteThere is high chance that whatever drives it's gate was damaged by current flowing from collector into gate..

author: spilihps
author_rank: Regular Contributor
timestamp: December 28, 2019, 08:51:33 pm
content: Yeah! I'll have to try to check that out in the morning.A fast glance, it seems that gate is driven from an IC marked 9506 / NT520If that makes any sense

author: spilihps
author_rank: Regular Contributor
timestamp: December 29, 2019, 12:25:12 pm
content: So gate is connected to pin 6 on the IC attached.This one does not give any Google results either..Edit! It seems to be a Phototransistor.. The symbol name on the board is "PC"Found a partnumber named PS9506 and it sugests to be for a IGBT gate driver..Probably would be best to replace it or at least try to test it..

author: SpecialK
author_rank: Regular Contributor
timestamp: December 29, 2019, 01:51:25 pm
content: Quote from: spilihps on December 29, 2019, 12:25:12 pmLooks like one of these:https://www.renesas.com/us/en/doc/YOUSYS/document/003/r08ds0018ej0100_nepoc.pdfOptocoupler/gate driver.

author: spilihps
author_rank: Regular Contributor
timestamp: December 29, 2019, 02:00:54 pm
content: Yep, it sure does..I think that is pretty good.. That should have isolated the rest of the circuit pretty good..It may even have survived? My local distributor dont have a IGBT specific optocoupler in stock..

author: spilihps
author_rank: Regular Contributor
timestamp: January 01, 2020, 05:11:09 pm
content: I have digged a bit more in this circuit now.The gate is connected via a 1K resistor to Vo pin on the optocoupler. That resistor checks out fine.Is there a good way to do some basic tests on this kind of optocoupler with a DMM in circuit?The best thing would ofcourse be to replace this with a new one just in case. However that will currently set us back about a week with shipping right now.

author: magic
author_rank: Super Contributor
timestamp: January 01, 2020, 05:28:34 pm
content: There is only one thing you can do with a DMM and it should be obviousDisconnect the LED, apply power, verify that the output is low.Send a few mA through the LED (see the datasheet for how much), verify that the output is high.

author: spilihps
author_rank: Regular Contributor
timestamp: January 01, 2020, 05:34:17 pm
content: Hehe, yes, well, there is also a "signal processing circuit" that they specify in the datasheet.I guess that is in the "block" connecting the two transistor symbols on the top view diagram.Ill guess i pull it and hook it up outside of the circuit then

author: magic
author_rank: Super Contributor
timestamp: January 01, 2020, 05:38:05 pm
content: If you are lucky, the circuit will do half of the job for you and attempt to drive it permanently low or high.The other half could perhaps be realized by shorting something or connecting a temporary resistor to VCC/VEE somewhere.

author: spilihps
author_rank: Regular Contributor
timestamp: January 01, 2020, 07:01:17 pm
content: Pulled it and tested it outside, works great! So i guess the optocoupler is ok.Now, i did not test it with a real world load though. Could that make a difference?

author: magic
author_rank: Super Contributor
timestamp: January 01, 2020, 08:50:06 pm
content: Dunno, you could add a pullup resistor to the output and see if it can drive it down. Be mindful of power dissipation, because gate drivers normally charge/discharge capacitances and don't drive continuous loads. Also dissipation in the resistor will be nontrivial for any significant test current. Perhaps you shouldn't go too far with that testing.

author: spilihps
author_rank: Regular Contributor
timestamp: January 01, 2020, 10:19:22 pm
content: Yeah, i feel a little more confident that its OK now atleast. So i will re-mount it and hope for the best.Will report back!

author: spilihps
author_rank: Regular Contributor
timestamp: January 11, 2020, 12:03:31 am
content: Update! The transistor arrived, the card is back in the unit and everything works again!Special thanks to wraper for the invaluable information about the transistor. Still don't know we're you got hold of it!Also magic thank for some brainstorming regarding the gate driver. It had magically survived though.