Marantz PMD-430 replacement motor availability?

The war horse HS-JS415 isn't resetting as I've gotten it to do in the past. As for the PMD-430, the 2200uF/10V (as opposed the 16v next door, I just examined) is replaced and made no difference. I've double-checked, double cleaned all the spring loaded contacts and the record enable switch. I did find two of the conductors on the motor feed (black wire) line that were left too long at the factory and had been bent together and were touching, (the two on the left side) so that's not a good sign. I clipped the excess length and renewed the connection. I'll take voltages at the motor again and see what happens.

 

Thanks for the suggestions, everyone. Nothing's fixed yet. The only news is the motor tested good. One less thing.
It still seems like part of the unit is getting power (the DC-DC converter at least SEEMS to be okay) as parts of the audio circuits are getting power, but the motor (obviously) and the heads aren't. Either that or there's a muting circuit that won't disengage.
I bought a belt kit for it, but frankly the belts that are in it are "okay" if not "new". Tight enough to function, at least.

I'm welcoming suggestions, as always. TIA!

 

Did you check if the motor driver ic is getting voltage? there are a bunch of expected voltages noted around QM01 on the SM, some are going to the IC like the 4.5 battery voltage, and some are generated by the ic like the reference voltage going to the sped adjustment, that should give an idea if that is ok or not

 

Thanks, gmac34!
I'll take a look as soon as I can get back to it.

In the meantime I did find a fairly reasonably priced second 430.
What comparing the two taught me is there are either two very different production runs or the first (my original) machine is missing a surface mount transistor on the main circuit board.

The second machine needed belts (installed), had one meter grounded out (fixed), one knob had come unglued (the LC record) and had numerous floating ground issues.

But it going great guns, now.

The belt replacement was a lot more trouble prone than I thought it would be.

Bob (Vintage Electronics) sent a fast wind belt that was entirely too thick. That's the first time I've ever had that happen.

I had to pull one out of my "generic belt" stash.

Getting those things to seat correctly so the rewind would work like it was supposed to work was deceptively tough.

(Newbie griping, I realize.)

I put it on my Leader W&F meter and it's well under spec. I did have to recalibrate the Right meter (somebody had jacked it up to maximum) and recalibrate the speed.

I now see why people have great affection and loyalty for them. That's what I had hoped would happen with the first machine. Not sure if I should keep trying to ressurect it

or just use it as a future parts donor.

Just thinking out loud. I'd like to have a functioning backup. One has the white printing and the first has gold colored printing on it.

 

I remember seeing a service manual with a service bulletin attached mentioning a revised board, with a different part for the headphone amplifier and revise EQ values (to fit updated IEC standards), but I'm not sure if that justifies the missing transistor. The gold printing and motor on rubber mounts should indicate a later machine.
I measured the "original" belts kit I got from super scope when I got them, but it seems you have put together a set already https://www.tapeheads.net/threads/marantz-cp-pmd-430-221-420-230-etc-belt-sizes.96067/

I would recommend calibrating the record levels and bias for the tape you wish to use, especially if you wish to use dbx, it can give quite weird results otherwise.

 

Thanks for that link! I'll put together another set from your specifications. Another very weird thing about the first (gold print) machine is the belts on it are good, if not new.

Agreed. Historically, DBX breathes and pumps a bit much for me, but that was based on my experiences with that rebranded NX-40 Type II DAK Industries outboard unit from the late '80s. It performed better with the vinyl that came with it. Now I wish I'd kept those LP's and bought a better processor.

The earlier (white lettered) machine is the second (100% now) restored example.

The "problem" child is the one with the gold lettering. It lived a much harder life. It had surface rust on the interior that I buffed out. The seller refunded most of the price, so I'm still under my target outlay. But ancillaries and parts may push past it.

I'm going to take a closer look at it.

Cosmetically, the gold lettered (#1) is the lesser of the two, based mostly on a few scuffs on the door. Most have buffed out, but there are a few stubborn marks left. The case cover is (I now realize) missing the front fold down cover.

The highs are quite extended and clean. The deep bass may not be quite as ruler flat as my TOTL Naks and Pioneers. I might need to raise the overall PB level and raise the internal bias a bit. It's pretty input/output close as it is now, though.

One thing I haven't gotten a lot of feedback on is that unbranded AC adaptor. Two things: It appears to work fine in spite of being specced (on the exterior) as 400mA low as compared to the Marantz DA-36.

It reads higher on the battery level indicator than fresh Alkaline Energizers do. I'm trying to use what I have up, I won't leave them in the machine, that's what the AC adaptor's for. Some of them I've had NOS since about 2016.

The only (other) things I have that uses them are a couple of classic portable transistor multi-band radios. (Zenith Transoceanic 7000-2 and a Realistic DX-440)

 

I made a few usb to Center negative barrel plug cables and use some old iPhone chargers(5v 1A), they work fine. Still, I think 400mah is enough and you would need more only if you tried to recharge batteries inside the machine while playing. I made a lithium battery pack that charges inside the unit for mine, that’s part of the reason to use the iPhone charger rather than the original.
But overall the marantz is not particularly picky about adaptors. The original says 4.5v but it’s a unregulated power supply, and will put out more than 6v without load, the recorder will also work fine down to almost 3v (discharged lithium battery) thanks to the dc dc converter/booster.

I hight recommend dbx for live recordings but it’s kind of useless for mixtapes. It is delicate system that will magnify any defect in the recording. The fine bias on the marantz is far from enough to tune the machine for a different tape to use dbx. You have to use the internal pots. If you do that the results are great, but I see why it got “bad press” as it is not user friendly and probably should have remained a technology for the professional market.

 

Just to clarify, the AC adaptor (the same one that Samscellar sells on eBay, I think) is 400mA LOW, compared to the DA-36, as I read it. It's rating is 300mA and the DA-36 is 700mA.

I'm going to send you a PM, if that's okay. That Lithium battery pack is just the thing I was thinking about. Making one's own takes some soldering skill and nerve. Congrats on that...

 

300mA might be low on paper, but if the battery indicator still indicates higher than fresh batteries it still means it's providing enough voltage (maybe 5v?) to make things work, I would not worry about it unless the adapter gets significantly hot.

 

Epilogue: I called in the "heavy artillery" (James Lane) and as it turns out, the motor IC and some corrosion on the board were the culprits. Those hit me exactly where I have visual acuity and fine motor control (LH, I had a titanium neck plate put in after ignoring an injury from a traffic accident and then played trumpet professionally on the injury for about a decade without knowing why I was starting to drop stuff) issues. James really came through and at a VERY reasonable fee. I can't recommend him HIGHLY ENOUGH. On top of that, he's a truly NICE person.

I do appreciate everyone's help. Now that I've stuck my toe in the portable audio restoration water, I think (apart from a Sony TCD-D8 that's a little sleepy) I'm about where I want to be, which is USING my newfound collection rather than working on it.

Best to everyone, stay safe and happy listening!

 

Good, so now you have two 430, better start recording something!