Marantz PMD-430 replacement motor availability?

To draft off of the "Apocalypse Now" trope: "The Motor...The MOTOR..."

Or another favorite from my young years:

"It's dead, Jim".

I've never seen a cassette deck motor so (sorry, I'm in a silly mood today) "bereft of life". Doesn't turn, doesn't vibrate, doesn't even want to think about having a rotational aspiration. I tested it at the board and it's getting voltage. Are there sources or drop in substitutes? TIA, everyone and thanks for the warm welcome.

 

These are beautiful machines and worth saving. You might be able to search for the part number or just pick up a spare non-working unit (where the motor works of course). I did see one on eBay for about $200 untested- but includes the cover which is pretty rare in itself. You can ask the fella to at least power the unit to see if he can hear the motor spin. Maybe offer a lower price too? And oh, have you tried banging on the motor with some pliers? You know, CPR stuff?

 

Yeah, I appreciate your suggestion, but no amount of "Emmet's Fix It Shop" deep tissue massage appears to be helping. I'm in mourning about it...I'm looking for a substitute. Any help or advice is appreciated. BTW, I don't see any fuses anywhere. I have downloaded the SM but I'm not seeing any jump out there yet either. I'll take a second look.

 

I would suspect it's a Mabuchi as nearly all Japanese tape decks of that vintage are. The SM part number is MM 071 and the MM00450020. If you can turn something up that will fit that space (it's recessed down into the plastic frame of the front part of the deck, IIRC) I'd wager that it can be speed corrected at the closely located variable resistor. I believe I saw it marked as being for just that purpose. Thanks so much!

 

Hi, there are two motors for the Marantz, the early one is "unbranded" and mounted directly on the metal bracket, the later one is mounted on rubber bushin and it's a RF-330T-13250 Mabuchi, you can find the second, brand new, on eBay from many vendors. They should be electrically interchangeable but the holes pattern is different, so some reworking of the bracket is needed if you have the older motor. Here a picture of the Mabuchi with his bracket .

 

Also, https://www.ebay.com/usr/samscellar13 this seller has acquired the remaining stock of spares from superscope (marantz US distributor) he might also have it in stock and maybe with the bracket. He has way more stuff that what is on the eBay store, so you should ask directly

 

Thank you gmac34! Much appreciated advice.
I think I bought some Mabuchis many years ago. I need to go through them and make sure I don't have one on hand already.
There was no marking on the exterior of the motor I took out. I believe there was a spring like coil surrounding it in the bracket, but the bracket and screw holes looked identical to this photo, including the shock mounts.

I put everything back together with the intention of returning it, but I think I'll hang onto it for a bit yet.

I'll update you as soon as there's more to know.

 

Update: The (biggish) 10v 2200uf PS cap is bulging, but the deck appears to be getting power. The Battery level shows full strength.

I noticed that the record circuit did power up when I first got the unit but doesn't now, but there's no telling how long it's been since any power was last applied.
I'm pretty certain nothing untoward happened in disassembly, but it doesn't make sense that part of the unit would be responsive while the rest of it isn't.

I'll see if I can find a replacement cap in my parts stash.

 

the caps in these often leak, take a good inspection around for any sign of corrosion. In mine the capacitor near the dc dc converter (metal can) leaked and made a mess, it took me a while to notice as I it is tucked under a wiring harness.
A Bulging cap could also mean that someone powered it with a reverse voltage, I would also check the dc dc converter, that would go bad quickly with a reverse voltage applied, do you get 14-15v out of it?

 

No, it's 4.5vdc/.3A center Negative. (Edited for accuracy.) I know that's .4 amp low, compared to the original DA-36. It has to be returned to the online seller. The area around the cap is fine. The cap didn't leak. But when I started cleaning the deck up I noticed it had been in a high humidity environment. I had to clean some crud off a circuit board (no corrosion, though) and some surface rust off of one corner bracket. The motor never did power up. But now the audio circuits are partially down. You can hear the noise floor of the machine but it doesn't pass audio.

 

It should be center negative!

 

Yeah, I was away from it when I posted and fumble fingered it. It's correct, as you specified. The adaptor still isn't supplying enough current, I suspect. The vendor said they'd refund it and I can keep it. So maybe I can use it elsewhere. The motor won't function on batteries either, so that never was the problem. I'm waiting on caps to arrive. It's turning out to have more unpleasant surprises than I thought there'd be. I'd like to have a working 430, but the main reason I chose it was because the Sony alternatives are soup to nuts crazy in terms of prices now.

 

That's also the reason I picked up a few "parts" TCS-430's. I wound up with two using parts from the (annoyingly) most expensive third. One functions perfectly, post alignment, the second works perfectly except for the speaker output (so low, as to be useless-which isn't much of a liability really) and the third is now being stored in the parts cornfield. I swapped the speaker, and they both were fine. (I couldn't imagine how one could be blown in circuit, honestly.) But the amplifier chip might be a different matter altogether. I know they're no WM-D6C, but it's close enough for large scale Orchestral Classical Music, lol. I looked at the 5 Pro II's and got a pretty bad case of sticker shock from those, too.

 

I see what you mean about the DC to DC converter now. It's the little silver box close to that bad cap? (Again, typing from memory...)

It seems like that's a likely culprit. That or what I read elsewhere as being a fusible resistor, RL51. I believe you were a big help with that thread also. I'll take readings. Thanks!

 

I want to add some information: this unit (as most devices made in Japan at the time) has a center negative plug (contrary to some statement above) and being powered with reversed polarity is common.
The first thing that will fry in this scenario is the motor governor IC (AN6612) which will need to be replaced. This will cause the motor not to run at all as it won't receive voltage.
It is not to be assumed motor is bad if unit powers on, but motor doesn't run. Motors can be worn and have play in the upper bushing, causing the belt to slip, but that's an entirely different issue.

If unit was powered with reversed polarity, the CD4011 in the VU-meter backlight timing circuit can also fry, resulting in no backlight. IC is readily available as it's an off-the-shelf part.
Depending on how high the voltage was when unit was powered on, caps on the power supply line can also buldge and possibly the DC-DC convertor can be damaged (although I have not seen or heard of DC-DCs going bad on these).
Measure the voltage at the DC-DC converter output, it should be around 15V if it's working. The design is very similar to SONY devices like D6C (built with discrete components only), so it can be repaired if faulty.

Note that a faulty DC-DC converter will NOT cause motor not to run, as motor governor IC is powered directly from input voltage (4.5V).

In the mono version (PMD221), the power audio amplifier IC will also fry if unit is powered with reversed polarity.

As for the unit itself, I have one in my collection (fully restored) and I like it especially because it's a 3 head design (which you don't really see in portables), it has dbx NR and fine bias adjustment (also very rare on a portable).
Apart from that, the TC-D5M (or any other version of TC-D5) outperforms it in terms of audio quality: noise floor is high on the PMD430 and wow&flutter (despite good for what it is) is nowhere near the 0.05% WRMS the D5 obtains.
Then the plasticky construction and the odd number of batteries are another 2 aspects I don't really like about the unit.

 

The DC DC converter provides 14v most of the audio circuit except from the headphone/speaker amplifier. The motor controller is powered directly from the battery/ac adaptor. I did you check if the motor IC QM01 gets power on pin 4 and 5?

The 430 is worth restoring, it took month for me to get mine working well, especially to get the wow and flutter under control. Now I think it can put up a good competition against any Sony, in particular if you record live music, wow and flutter will never be as good as the Sony but the dynamic range that DBX gives you is very useful when recording uncompressed (dynamically) material and much greater than a D5 with dolby B could ever hope to do.

https://mega.nz/file/EqYyQI4b#YG_ChRX5Gupu9NQsHG4G8rW7R9LQ5K54MAalH2RN_tU

here a recent recording made with my 430, maybe it can help keep you motivated.

 

It seems you replied as I was typing.. I agree on most points regarding the motor, not sure what RTM has tried, but a definitive test would just be to power it for a moment with a AA battery and see if it spins

 

There seems to be an ESL or some other issue regarding the meaning of what I've posted. I've tried to make this CLEAR:

The voltage and DC polarity of my AC/DC adaptor is CORRECT. However the amperage is too low. I wasn't physically WITH the AC adaptor (OR the 430) at the time of my AC adaptor reply and incorrectly stated the polarity in that post. Again, it is CORRECT. It also exhibited the same behavior before I acquired the AC adaptor. The AC adaptor is a Red Herring, except for its being rated 400mA too low.

I appreciate everyone's thoughts on the 430. While I'm a relative newcomer to portables, I have experience avocationally servicing cassette decks and reel to reel recorders. I've been doing those since the '80s. This started when an Aiwa HS-JS415 I bought in 1995 finally began to have belt issues about a month ago.

I thought now was as good a time as there'll ever be to become familiar with portables. I found a few that looked potentially worth getting to know, at (for me) not completely outrageous prices. At those prices of acquisition, I expected them to need attention. (But in the case of the 430, not THIS much attention.)

I picked up a second HS-JS 415 (the jury's still out on it, but I suspect replacing the belts on it will be all it needs, I cleaned the unit up and it appears to function except for the belts), the aforementioned Sony TCS-430s (Two out of three ain't bad, and I'm still under $50.00-relatively cheap thrills) and this 430.

I'll repost that I see voltage being passed to the meters, battery check, and parts of the audio circuit, but NOT the record bias circuit and it doesn't pass audio. The auto-stop solenoid works like the day it was new, and you can hear it through the headphones and see it on the meters (very small movement) when it actuates.

So SOME voltage is getting through the DC/DC converter. I have a replacement cap now and I'll take measurements after I install it. Thanks again, GMAC34 and Mister X for your advice and Valentin for his observations and opinions. I'm a little discouraged about the PMD430 but time will tell.

 

The new to me HS-JS415 is completed and working 100%. One less thing. The "1995 Circuit City demo" not new to me at all 415 is reverting back to some of the flaky chip sort of behavior that I knew it to have off and on over the years. Motor runs-when it wants to-doesn't when it doesn't want to. The power LED stays on regardless of the mode of operation. I've tried to reset it, but sometimes it takes and sometimes it doesn't. Mostly, right now, it doesn't. So it may become a future parts donor for the "new" HS-JS415. I used it to record performances (I'm a retired professional musician/teacher) for years before I bought a Sony TCD-D8 in around 1998 or so. But the 415 worked pretty reliably every time I pulled it out over the last ten or so years. I replaced the belts about that time, IIRC.

Weird. I'll pull the batteries out and let all the chips lose whatever residual charge they might have retained. Back to the 430. That cap is up next.