Author Topic: Tascam 424 mk3 not recording on channel 4  (Read 49 times)

Stefan Paul psychboy86

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Tascam 424 mk3 not recording on channel 4
« on: November 16, 2018, 10:51:53 AM »
Jay,
I wanted to ask you about this 424 I picked up on ebay recently for a pretty good midnight bidding price. It showed up and I was so excited to upgrade from my 414 (this only has a low and hi EQ on the mixer, but those two midrange knobs on the 424 are where it's at!) but it turns out this 424 doesn't record on channel 4, although I can get a line level signal. I've tried to route all the inputs and still nothing records onto Channel 4. I cleaned the tape head and all those surrounding parts, like Mike's cleaning video shows.

I work with a few electronics gurus at my job, and when I explained to them what the problem was they said it's definitely the tape head that needs to be replaced. I just wanted to get your input on this since you know a lot about 4-track recorders and my co-workers are coming from more of a general electronics perspective.

thanks,
Stefan

mike

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Re: Tascam 424 mk3 not recording on channel 4
« Reply #1 on: November 24, 2018, 12:42:11 PM »
I remember asking Jay about this because mine had a similar problem. Audio cutting in and out on 4. On mine it's def something wrong with the channel on the mixer. I would venture to guess it's something wrong with your channel 4 as well. Jay made a great point when we were discussing mine; the head on the 4-track is like an 1/8" wide; it's highly unlikely for that small strip to "go bad". You'd think the entire head would be bad at that point. Esp for channel 4 which would most likely be used the least.

I think I'm going to swap channel 5 or 6 with the 4th channel at some point. I rarely use 6. I'd rather have channel 4 fully functioning.
Mike

Stefan Paul psychboy86

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Re: Tascam 424 mk3 not recording on channel 4
« Reply #2 on: December 05, 2018, 03:32:02 PM »
Thanks Mike! I just re-watched the "How to fix a broken 4-track" video again. While I don't have a test tone device like Jay does, I do know some electronics wizards who have worked on a few things. I'll inform them that it's not likely to be the record head. I'll have them check of the solder joints and cross my fingers that it's an easy fix. I'm still a little peeved at the seller on ebay for burning me on a "fully working" machine that doesn't work on one channel. They offered me a refund or partially pay for getting it fixed, and it was purchased at a pretty good price, but it still seems like a slimy thing to sell a product that doesn't match the description.

mike

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Re: Tascam 424 mk3 not recording on channel 4
« Reply #3 on: December 06, 2018, 09:35:42 AM »
Yeah, that sucks. I think it may be a case of people not knowing how to test them properly. But also, they are easy to con off on someone because by the time novice users learn to use it, they may realize too late that its busted. The 424s are not resilient at all.

I would take them up on the partial refund. Messed up to say "fully functioning" but then it's not.
Mike

Stefan Paul psychboy86

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Re: Tascam 424 mk3 not recording on channel 4
« Reply #4 on: December 06, 2018, 02:56:01 PM »
I'm going to try a few more things. I had a friend take it apart and hook up a multi-meter to the lead wires coming off the record head. He disconnected lead wires from the circuit board and stuck the multi-meter on the end of each wire to check resistance. The results: three of the leads read about 25 mega-ohms (that's 1 million ohms) and one of the leads measured at about 25 kilo-ohms (that's 1,000 ohms). I cleaned the head some more and channel 4 does record now, but it's at about one fourth the volume of all the other channels. I know another electronics wiz who can take it and check it out on his oscilloscope, but it'll be about a month or more until he can even look at it. Both the guys I talked to are still convinced it's the record head, and they've worked on similar equipment before, so I'll take their word for it since I don't know much about being an electronics technician.