N313 09 Transistor  - Page 1
Forum section: electronics / repair

author: Steve T
author_rank: Contributor
timestamp: April 05, 2024, 02:08:49 am
content: HelloIam working on a Hakko 850 hot air station and need help finding a transistor. It is marked “N313” with “09” below it. It is a through hole component with 3 legs and has a half cylinder shape (I’m new to electronics repair). I have searched online but I cannot find a definite part or substitute. Some sites call it a NPN transistor others call it a mosfet or a triac. Thanks in advance for any help.Steve

author: floobydust
author_rank: Super Contributor
timestamp: April 05, 2024, 03:04:07 am
content: I did find this schematic for Hakko 850B and see a unijunction transistor PUT1 as "N13T1" (NEC) in the TO-92 packagepicor 2N6027 as a substitute. That might be what you are looking at. It would also test weird even though good.other picshttps://www.eevblog.com/forum/reviews/hakko-850-hot-air-rework-station/Usually the triac gets cooked in these, heater shorts out etc.

author: Steve T
author_rank: Contributor
timestamp: April 05, 2024, 01:14:22 pm
content: Thank you for the reply.I have seen the 850B schematic but it looks different from the 850 that I have.I have attached a picture of the board and the component being tested on my Peak DCA75.The transistor fits in the spot marked D11, between the blue and green capacitors.Could the transistor be a small signal thyristor (I’m not sure what that is)?? Or maybe the transistor is good but cannot be tested on the analyzer?Steve

author: floobydust
author_rank: Super Contributor
timestamp: April 05, 2024, 04:41:25 pm
content: Not an 850Bor 850B-3but the early version. It's a bit of a mystery. Can you give a pic of the other side of the board, to figure what the part does. I can find no data on N313. Japanese discrete or thyristor databooks i.e. NEC never made it to the Internet.The PCB is labelled as if it's a small triac - A1, G, A2. Typical parts areMAC97or BT131 series or Z0106, all in TO-92 package.Small chance it could be a DIAC, if only 2 terminals are used. That makes more sense for pump speed control and would likely test open circuit as they don't do anything below ~30V. But you never know, Hakko was a bit unusual with their electronics designs of that era. So I thought to trace out the circuit a bit. Conn. VH3 is to the air potentiometer?I'm guessing bigger triac TH2 is for the pump, and H1 on the heatsink is for the heater.

author: Steve T
author_rank: Contributor
timestamp: April 05, 2024, 05:50:20 pm
content: I have attached a photo of the back of the board and drew a boarder around N313. You are correct that the middle pin is not used. If I test the two outer pin on the tester, the screen indicates that it is a diode?Also, I found some broken traces where a plug inserts and have soldered some wire leads to repair the. The heat now works.When I plug the unit in, the air pump works for a minute, then shuts off, which is normal. When I turn the unit on, I get heat and airflow, but cannot adjust the speed and the LED indicator does not light up. If I power off the unit, the air continues for a minute then shuts off, which is normal.Steve

author: Steve T
author_rank: Contributor
timestamp: April 05, 2024, 09:03:00 pm
content: I believe that I solved the problem. There was a broken trace where the diode connects to the wires post for the LED at the pump speed control.

author: Steve T
author_rank: Contributor
timestamp: April 05, 2024, 11:18:59 pm
content: Nope…..still having trouble with air speed. Seems to be stuck on maximum.

author: fzabkar
author_rank: Super Contributor
timestamp: April 05, 2024, 11:40:03 pm
content: TVSN13T1 and N13T1 are both substituted by NTE6402:https://www.nteinc.com/specs/6400to6499/pdf/nte6402.pdf

author: Steve T
author_rank: Contributor
timestamp: April 06, 2024, 04:59:04 pm
content: Thanks fzabkar. Could the N313 be the.reason 5hat I can’t control the speed of the airflow?Stev

author: floobydust
author_rank: Super Contributor
timestamp: April 06, 2024, 06:55:26 pm
content: OP what you describe does not make sense to me. D11 is now in-circuit? Connector VH3 to the air pump?The mystery part D11 connects to the triac TH2 gate, so I expect nothing happening, no power to VH3-3 if the part is out of circuit.The PC board has a lot of lifted pads and traces so I would suggest improving the desoldering skills. It is a cheaper phenolic board.

author: Steve T
author_rank: Contributor
timestamp: April 06, 2024, 10:03:59 pm
content: Hi floobydustYes it is back in circuit and the air pump is working but only at full speed. The pads were lifted when I got the unit. Actually, one of the capacitor legs was popped off of the board and the unit’s cool down function wasn’t working at all. At least I fixed that. Also, I didn’t realize that phenolic boards were more subject to damage.It’s true that am new to this hobby (my background is in healthcare) and am trying to learn as I go. Sometimes I buy old electronics that no longer work just to learn from them. Many times they end up worse than when I started, LOL. I’ll keep at it though and hopefully improve.Thanks for everyone’s help.Steve

author: floobydust
author_rank: Super Contributor
timestamp: April 07, 2024, 03:06:26 am
content: If the air pump is stuck at full speed, check triac TH2 for being shorted: T1-T2 open, T2-G open, T1-G 150-250ΩNEC AC05D 400V 5A TO-202 package, I'd go for a BT137-600E.Check the resistance of the Heater potentiometer (yellow wires VH3) to see if it is OK. Air "1" is 300kΩ, "8" is 0Ω.Found this, never used nitrogen before:Hakko 850 Modification for Nitrogen Supply

author: Steve T
author_rank: Contributor
timestamp: April 07, 2024, 03:26:42 pm
content: Got it! The VH3 resistance at position 1 was too low. I rotated several times while pulling on the control knob. It now reads 287 k ohms.Thanks for your help!Steve