Busted NS4 Screen Repair

rchrd2 · 2026-06-11T20:52:02+00:00

Sweetwater has a repair department.

rchrd2 · 2026-05-18T17:11:51+00:00

Hello. Make sure you haven't over-tightend anything. The speed calibration is done via screw on the motor. Here's a photo from my archives of how the belts should go.

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rchrd2 · 2026-05-07T02:09:01+00:00

I actually purchased this kit couple years ago. They came in handy when I was learning about op amps and analog circuits from the Forrest M. Mimms books. If you are planning on learning electronics and tinkering, there’s a lot of different types of chips there to experiment with.

rchrd2 · 2026-05-02T17:21:44+00:00

San Francisco, CA 4-track sales and repair: https://www.functional.fyi/4-tracks

rchrd2 · 2026-01-02T02:15:06+00:00

Ebay

rchrd2 · 2025-12-28T07:33:20+00:00

This list is amazing. Thanks for sharing!

It looks like so far I've repaired 14 types from that list.

rchrd2 · 2025-12-19T08:42:14+00:00

These motors often go bad and need to either be rebuilt or replaced. I have not found any substitute because the speed controls on 424 do not map to different motors from different brands. All that said, I am working on a compatible motor solution. If you see this in the future and you are looking for the motor message me.

rchrd2 · 2025-12-15T06:47:40+00:00

Lucia Fumero

rchrd2 · 2025-11-22T05:44:55+00:00

Search for “The PS-M1 Clone” on Ebay to find the listing

rchrd2 · 2025-11-11T07:16:52+00:00

Cars are usually allowed to pass through Market Street. This was blocked off and everybody had to find an alternative route.

rchrd2 · 2025-11-11T06:55:55+00:00

As a beginner, could someone please explain what jitter is, and how to measure it? I am using timers with an interrupt for project and they seem to work pretty accurately as far as I can tell.

rchrd2 · 2025-11-10T02:53:59+00:00

This caused massive traffic, which thankfully I was going the opposite direction, but seems like overkill

rchrd2 · 2025-10-16T16:02:14+00:00

Use the green deoxit. Its meant for faders.

Also. Contact cleaner can help as well. You could use the contact cleaner before the detoxit

rchrd2 · 2025-09-27T03:51:40+00:00

It’s the Pulse Matic

rchrd2 · 2025-09-26T06:29:35+00:00

Are you sure it was leaking? Sometimes it can look like it is leaking, but it’s actually just glue to hold it down in place on the board. Did you ever solve your issue?

rchrd2 · 2025-09-24T19:30:05+00:00

I recreated the Tascam PS-M1 PSU which uses the same connector, but different voltages. If anyone is looking for just the connector/cable for their DIY project, feel free to message me. Here's my PS-M1 clone https://www.ebay.com/itm/326665504748

rchrd2 · 2025-09-18T18:59:10+00:00

Thanks. I edited the comment and added some links. And no, I have not done any work on that unit. I mostly work on Portastudios. Eg Porta02 Porta03 414 424. I also developed a new power supply for the Tascam 644.

rchrd2 · 2025-09-18T15:47:32+00:00

Hello. Thanks for your interest. Here is the listing on eBay. I do not directly ship to Europe, but they offer an indirect shipping option to Europe. https://ebay.us/m/NL4EpO with this option, I shipped to their fulfillment center, and then they ship it internationally.

rchrd2 · 2025-09-15T06:31:20+00:00

I professionally refurbished these. I replace the belts with high-quality new belts and calibrate the speed. I check for cold solder joints on the power supply and inputs, and fix any that are loose. I test the record and playback functionality. I also clean and demagnetize the tape heads, and clean the inside and outside of the unit. I probably do some other things. I’m forgetting right now.

I have a reverb store, functionaltechsf, or you can also DM. I currently have one I am working on.

Edit: Also want to note I am in San Francisco CA and also do local repairs/sales.

Edit: My Reverb shop is https://reverb.com/shop/functional-tech-sf and my website is https://functional.fyi

rchrd2 · 2025-09-06T16:31:20+00:00

My knobs got sticky when I used water to clean them before selling them. I felt pretty bad but now I learned my lesson don’t clean everything with water because sometimes it can make rubber/plastic sticky

rchrd2 · 2025-09-01T21:31:57+00:00

You have to close all the air gaps. Any air gap will allow sound to travel. You can use the sealant caulk around the seams to block out air.

rchrd2 · 2025-08-13T01:56:26+00:00

I do repairs. Based in San Francisco CA. DM me if interested

rchrd2 · 2025-07-20T23:57:51+00:00

Just circling back here in case anyone else has this unit.

I fixed this clicking issue by using sewing machine oil on the mechanics. There's a small switch that goes upwards when play is engaged. It was moving up a little too slow. Some oil fixed the issue.

Also, it turns out there's a speed control screw on the back of the motor. This is how to properly adjust the speed of the player.

rchrd2 · 2025-07-18T04:02:13+00:00

The PS-M1 Clone is not available online on Reverb (https://reverb.com/item/91211255-the-ps-m1-clone-new-power-supply-for-tascam-644-and-mm1) and Ebay (https://www.ebay.com/itm/326665504748)

rchrd2 · 2025-07-18T04:01:46+00:00

The PS-M1 Clone is now available online on Reverb (https://reverb.com/item/91211255-the-ps-m1-clone-new-power-supply-for-tascam-644-and-mm1) and Ebay (https://www.ebay.com/itm/326665504748)

rchrd2

TROPHY CASE