Nakamichi RX-505

[ppeterso2]

I did a search and couldn't find an answer to this question, so I'm takin' it to the new post arena!

I have 2 Nakamichi RX-505's (never could afford a used Dragon...LOL). One works great and the other one I have currently disassembled, replaced the belts and trying to re-sync the autoload tray(URRRGG!!--driving me crazy!) .

I noticed that the cassette "lid lamp" is out on both decks (the cassette lid lamp never worked on either of mine--so I never really thought about them). On the disassembled one I pulled the PCB with the light bulb in it but can't find out, even with the service manual, what replacement bulb I need.

Help!! Anyone have the specs on this funny axial bulb? I have posted some pics from the SM: The lid lamp is diagram 5-10

 

[perryinva]

I replaced the bulb on one of my 505s with a 12VDC one from Radio Shack that was about the same size. Fit in the same little holder and everything. Cheap, easy, fast. Doncha just LOVE trying to line up the gears and keep the belt attached at the same time...what a blast!

 

[ppeterso2]

I replaced the bulb on one of my 505s with a 12VDC one from Radio Shack that was about the same size. Fit in the same little holder and everything. Cheap, easy, fast. Doncha just LOVE trying to line up the gears and keep the belt attached at the same time...what a blast!

Thanks for the tip! I will stop at RS on the way home! (glad it's not a 15v or 18v like Philips used to use!).

In regards to that wretched door--I was about to go through that whole process of seting the VR Pots to this voltage and all that other ridiculous stuff in the service manual when all I had to do was 1. point the cassette holder vertically and slightly lift that plate w/the gears and align the arrow straight down. The first time last night by snatching, I shot the new belt out of the back of the deck and had to look for it (I do stupid stuff sometimes).

Now I found out the left (take up) pinch roller assembly is seized on the shaft--ugggg!!! I took the arm off and then the actual roller and have the shaft soaking in alcohol--this thing is a bear!
Thanks again!

 

[Nakdoc]

And to boot, the service manual instructions have an error somewhere.

 

[diepbtt]

I did a search and couldn't find an answer to this question, so I'm takin' it to the new post arena!

I have 2 Nakamichi RX-505's (never could afford a used Dragon...LOL). One works great and the other one I have currently disassembled, replaced the belts and trying to re-sync the autoload tray(URRRGG!!--driving me crazy!) .

I noticed that the cassette "lid lamp" is out on both decks (the cassette lid lamp never worked on either of mine--so I never really thought about them). On the disassembled one I pulled the PCB with the light bulb in it but can't find out, even with the service manual, what replacement bulb I need.

Help!! Anyone have the specs on this funny axial bulb? I have posted some pics from the SM: The lid lamp is diagram 5-10

lid lamp 12 V, 60-70mA

 

[ppeterso2]

lid lamp 12 V, 60-70mA

Thanks diepbtt! At first I put in a red 12v-60mA lamp (trying to be custom), but it wasn't bright at all. So I heated up the soldering iron and put in a 12v-25mA clear bulb (radial leads--ran the lead wires through the holder). It lights up fine now--then I read your post. Should I be concerned about the 25mA's?

Put it all back together (at least 3 times...sometimes, I swear...it takes me forever..LOL!) Deck sounds very very good!!! But, I Noticed another bad issue: Master fader is stuck on down and when I try to enter record I get "rec mute" on all the time. I thought maybe one of the buttons were stuck during reassembly, but they're all fine--problem seems logic. This really my first time using this spare 505--so something could have been wrong with it before....

 

[diepbtt]

Thanks diepbtt! At first I put in a red 12v-60mA lamp (trying to be custom), but it wasn't bright at all. So I heated up the soldering iron and put in a 12v-25mA clear bulb (radial leads--ran the lead wires through the holder). It lights up fine now--then I read your post. Should I be concerned about the 25mA's?

25mA means the resistance of the lamp or the brightness of the lamp. it may not enough bright as original lamp(60-70mA for much brighter) but when you find it OK then do not be concernd about it.

You can use a white or blue LED added a resitor of appr. 390 ohm to the (+) anode leg(longer leg of the LED) if you can not find a replacement lamp.

 

[perryinva]

The 25mA will give less heat and less light, but enough that it works to see the label. Rare is the seldom used 505 that doesn't have siezed pressure roller arms. Of the 5 505s I've worked on only 2 arms out of ten were not stuck, siezed or too stiff. You have to be carefull when you put pressure in the split on the brass holder with the fine screwdriver blade to not bend it or the shaft. Since the tape quide is attached to the pressure roller arm, you have to have either a Nak tape guide jig or an IT-300, or Willy Hermans WHS-300 alignment jig to set the arm back on the shaft with the correct spacing. It is virtually impossible to get correct tape guide alignment without one. The tolerance is very small. Hopefully, you measured the exposed shaft carefully before pulling the arm off, and will get it in the same place, but even then you will find some tapes play fine, but others get eaten or skew too much. Hopefully you know someone local that has one to borrow for the 5 minutes you need it. They aren't cheap.

 

[ppeterso2]

The 25mA will give less heat and less light, but enough that it works to see the label. Rare is the seldom used 505 that doesn't have siezed pressure roller arms. Of the 5 505s I've worked on only 2 arms out of ten were not stuck, siezed or too stiff. You have to be carefull when you put pressure in the split on the brass holder with the fine screwdriver blade to not bend it or the shaft. Since the tape quide is attached to the pressure roller arm, you have to have either a Nak tape guide jig or an IT-300, or Willy Hermans WHS-300 alignment jig to set the arm back on the shaft with the correct spacing. It is virtually impossible to get correct tape guide alignment without one. The tolerance is very small. Hopefully, you measured the exposed shaft carefully before pulling the arm off, and will get it in the same place, but even then you will find some tapes play fine, but others get eaten or skew too much. Hopefully you know someone local that has one to borrow for the 5 minutes you need it. They aren't cheap.

Yes, I marked/measured the shaft before I removed it and so far no skewing or krinkled tapes--yet--but I've only tried 3 different tapes thus far! Just that the Master Fader is electrically stuck on down and the Rec Mute key comes on as soon as I enter record standby. It plays and erases fine though. My other 505 works correctly and I see the fader should be up when powered on. I have to find out which caps I need to replace to restore operation--but hey, this was a spare, parts 505 and the fact that it plays is a bonus.

I wasn't so lucky with my LX-5--it won't play a tape because when I tried to pull off the nut the whole wretched Pinch roller arm shaft came out...I will have to find the jig to handle that one.

Thanks for the info--btw Naks and Teac X reel to reels--that congealed grease issue is a royal pain in the neck!

 

[perryinva]

Where are you located?

That was why I mentioned being careful when you spread the brass collar to remove it from the shaft. The SS shaft will pull right out of the nylon if it is pulled to hard and bent or on an angle. It can be reinserted and a little heat will seal it back in place, it just has to be square/plumb when done. Whatever grease they used during that era is worse than most cements. If you remove th ewhole transport, it is much easier to work on than in the deck. Then you can also use acetone without fear of dissolving any black plastic.

 

[ppeterso2]

Where are you located?

That was why I mentioned being careful when you spread the brass collar to remove it from the shaft. The SS shaft will pull right out of the nylon if it is pulled to hard and bent or on an angle. It can be reinserted and a little heat will seal it back in place, it just has to be square/plumb when done. Whatever grease they used during that era is worse than most cements. If you remove th ewhole transport, it is much easier to work on than in the deck. Then you can also use acetone without fear of dissolving any black plastic.

I'm in Hampton VA: my poor LX5 lol! It worked fine if you could wait 2-3 mins for the supply roller to engage--but noooooo, I had to be in a fixin mode...lol! I should have removed the transport on it first... Now it garbles--dragging btw slow and stop. I fixed the supply roller arm--but had to free up the take up roller too....

 

[perryinva]

Well, I'm in Richmond, and have all the Nak gauges and cal tapes. PM me, and maybe I can help.

 

[okzt]

Rec Mute key comes on as soon as I enter record standby. It plays and erases fine though.

Hi there.
I found that my RX-505 have the same issue with rec mute key being activated as soon I'm starting to enable record function. The REC MUTE LED lights all the time and button have no any reaction and doesn't work.
I did all what I can. first of all checked the tact button on control pcb, then replaced all orange caps on WIMA, checked two transistors (Q632, Q633) in oscillator circuit on logic pcb and then checked transistors(Q302, Q304-308) in recmute circuit on main pcb.
It all seems good, but the issue still here. I'm out of ideas maybe anyone can help me. Thanx.

 

[perryinva]

IIRC, it is typically a failed transistor not directly in the recmute circuit that causes this issue, assuming the CdS photoresistor is still good. The key was to trace where the signal was grounded (or high, I cannot recall) on the rec mute line. It has been a long time since I fixed that issue on a different deck.

 

[okzt]

Thanx for you answer. I'm still in searching of the key. I checked all transistors in mute line and all of them are seems good.

assuming the CdS photoresistor is still good.

May the failed CdS calling this issue? So I have the audio signal in source mode and the fader up & down functions works properly during record mode activated.
Thanx

UPD: CdS301 is good.