Author Topic: Eden Nemesis NA320 - Blown Fuse  (Read 127 times)

Offline neurotic

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Eden Nemesis NA320 - Blown Fuse
« on: May 12, 2019, 06:17:51 AM »
Hey everyone,

First post here and unfortunately it's for a tech issue.

I have a Nemesis NA320 head which seems to have an important issue because it keeps blowing the mains fuse. This happened during a rehearsal. I changed the fuse the next day and since then it keeps blowing.

I opened the chasis to see if there's anything obvious. I did various trial n errors and realized that removing the power amp section from the PSU card, didn't blow the fuse. So, I guess the problem is somewhere there.

Did anyone have a similar issue? Any suggestion? Any part that is suspect for similar issues?

Thanks in advance!

Offline Rip Van Dan

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #1 on: May 13, 2019, 02:49:20 PM »
Welcome to the Garden!

Sorry to hear about your problem.  A simple question before the real gurus check in, did you replace the fuse with a SLO-Blow fuse.  If not, you need to do so.  Standard fuses will blow as various peaks in current pass through them.  Slo-blows will blow sometimes due to age, but usually because there's a real problem.

Dan
Rip Van Dan
Dan Gracia
'82 US-made Fender Jazz Bass with maple neck
5-string Rogue LX405 Pro (Surprisingly good "no-name" bass)
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Offline neurotic

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #2 on: May 13, 2019, 03:26:07 PM »
Hey Dan,

Thanks so much for the reply. Yes, unfortunately it was a slow blow fuse.

Takis

Offline Rip Van Dan

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #3 on: May 13, 2019, 08:26:42 PM »
Nuts, so much for the quick fix.  Perhaps Armin can help you figure it out.  He's Bassmann1968 here on the forum.

Dan
Rip Van Dan
Dan Gracia
'82 US-made Fender Jazz Bass with maple neck
5-string Rogue LX405 Pro (Surprisingly good "no-name" bass)
WT500/800 Highwayman (signature model)
D.N.S 410-8, Eden EX112 x2
Line6 G10s wireless
==
spares:
Eden RS400, GK BK250, BPX115 cab, acoustic B410 cab, Sunn Beta 202 (2x12)

Offline Bassmann1968

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #4 on: May 14, 2019, 06:56:01 AM »
Hi Takis and welcome to the Garden!

Sorry for the late reply.
Do you have a picture of the inside?
Which plug did you remove to avoid blowing the fuse?
What is your HV+/-?
Rock on!
« Last Edit: May 15, 2019, 12:25:53 AM by Bassmann1968 »
Armin

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Offline neurotic

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #5 on: May 14, 2019, 09:40:15 AM »
Hi Armin,

Nice to e-meet you!

Thanks for your reply. Yes, I can send you a picture of the inside.

FYI I removed the HV┬▒ cables.

Offline Bassmann1968

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #6 on: May 15, 2019, 12:32:57 AM »
Ok, then I would check/change the MOSFETs.
I think there are 6 of them?
Armin

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Offline neurotic

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #7 on: May 15, 2019, 01:23:47 AM »
Hi Armin,

Thanks! Yes, there are 3x 2sk1058 and 3x 2sj162. I have already tested their on/off state with my multimeter. One of them looked faulty and I replaced it. However, problem perists. I'm going to do an extra check on Friday in case I have missed something.

If you have any other suggestion, I would really apreciate it.

Thanks for the help anyway.  :)

Offline Bassmann1968

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #8 on: May 17, 2019, 08:35:29 AM »
Which of the 6 do you think is not ok?
Speaker was disconnected?
Armin

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Offline neurotic

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #9 on: May 21, 2019, 03:46:45 PM »
Hi Armin,

Thanks so much for the follow-up. Here's an update.

Today I replaced the previous FETs. Now all FETs are brand new. I cannot remember which one wasn't ok, because I did that really quick, but I think the first 1058 was faulty. But really cannot remember. I'm really sorry!

Anyway, after replacing the FETs today, the fuse unfortunately was blown again. :(

Yes, I had a speaker connected. I think that I listened a DC like sound before it got blown. I start thinking the capacitors between gate and drain should be responsible for it, but they look fine. Is it possible to verify their capacitance/voltage for each one of them?

Offline Bassmann1968

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Re: Eden Nemesis NA320 - Blown Fuse
« Reply #10 on: Today at 12:21:52 AM »
Hi,
disconnect the speaker with the switch. Still blows the fuse?
Disconnect HV+/- from the power amp section and measure dc voltage between Gate N and Gate P (SCN401).
Armin

PLEASE LIKE EDEN ON FACEBOOK!!!
No schematics available!!! Don't ask for it.
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WTP-Pre,1350,WTX260,WT300/400,WT1000,WTX1000N,NAV,WTDI
D112XLT,D210XST,D410XLT,D810RP,DNS410,DNS112