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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 19th Jan 2019, 5:49 pm   #1
nmooney
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Default Akai 4000DS Mk2 right channel going crazy.

I have bought an Akai 4000DS mk2 that has not been looked after. It has obviously been stored somewhere damp. I did manage to get it working and sounding great playing prerecorded stereo 7.5ips tapes. But the right channel starts to make big crackling noises and the uv meter starts moving back and forth violently. The channel still works inbetween, and it has been intermittent. Any ideas where i should start with this or what could be causing it. If it's going to be a capacitor I'm up for trying to recap it myself. But would be good to know where to start. See this video of the uv meter. This is with no tape playing across the heads.

https://youtu.be/wkSHUuLsUZo
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Old 20th Jan 2019, 2:52 pm   #2
Michael Maurice
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Default Re: Akai 4000DS Mk2 right channel going crazy.

The problem is usually caused by the now obsolete LD3141 IC. Some people sell replacements.
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Old 21st Jan 2019, 12:01 am   #3
electroanorak
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Default Re: Akai 4000DS Mk2 right channel going crazy.

I have a few LD3141's. I could part with one FOC of course?

It will be that, I have had this fault before.

I am away until Sunday, so I can post one next week.

Daniel.
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Old 21st Jan 2019, 1:40 pm   #4
monaro0162
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Default Re: Akai 4000DS Mk2 right channel going crazy.

LD 3141 were only used in the 4000DS MK1, the MK2 switched back to using discreet components.
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Old 21st Jan 2019, 4:02 pm   #5
julie_m
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Default Re: Akai 4000DS Mk2 right channel going crazy.

The track select switch on these machines can cause all manner of problems .....
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Old 21st Jan 2019, 10:39 pm   #6
nmooney
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Default Re: Akai 4000DS Mk2 right channel going crazy.

I'll open it up again and have a look. Now that i have had a read about the LD3141 ill have a look and see if they are in there. I had ever read conflicting information on whether they are in the mk2.
I saw a couple off people were replacing them with small circuit boards with the components on them, rather than integrated chip.
I had thought about the track selector switch. When i switch it between sterio and the 1&3 and 2&4 mono tracks the popping and cracking noises still come through. So it had raised my suspicions. Should i get some contact cleaner in there?
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Old 22nd Jan 2019, 12:57 am   #7
dave walsh
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Default Re: Akai 4000DS Mk2 right channel going crazy.

Yes... my machine has these problems with the switch and [so-far] I've kept it going [for transcription purposes only]. But then, I'm not expecting to record or play back on it regularly, as in the 1970's! Luckily the "monkey metal" cam hasn't disintegrated [yet] either. If it does my Tandberg 3300X seems to play back the archived tapes just as well

Wholesale recapping without fore-thought is not recommended on here as it's seen as a form of counter productive guess work. There are [or should be] very many 4000D threads available to read.

Dave W

Last edited by dave walsh; 22nd Jan 2019 at 1:06 am.
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Old 26th Jan 2019, 10:47 pm   #8
nmooney
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Default Re: Akai 4000DS Mk2 right channel going crazy.

Messing with the track selector switch has not improved things. The right channel is almost completely dead now. UV meter only moves a fraction. Opened it up and think i have identified the offending LD3141. Looks like there is a place in the Netherlands selling them.


https://www.electro-andijk.nl/index....category_id=10
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