UPDATE: Nakamichi BX-300 Repair - NEW Problem

[EADGBE]

Hello Everyone:

Here is an update on my Nakamichi BX-300. This is the same tape deck
that has flickering
digits in its counter and keeps resetting its counter back to "0000"
AND keeps
putting itself back into PLAY mode - even when there is no tape in the
machine.

I have solved a couple of problems but caused another.

First of all, I have narrowed it down to IC701 on the counter PC
board. This IC
chip (microprocessor) apparently was faulty.

In the Nakamichi service manual, this chip is listed as LM6416E-106

I found an LM6416E at an online parts source that caters to repair
techs. There was no suffix of any kind
after the "E". It is just a "regular" LM6416E. I thought this IC was
the same
as the faulty one in the BX-300, but it's not.

FIRST THE GOOD NEWS: After I installed the new LM6416E chip, the deck
no longer
has flickering numbers in the counter and the deck no longer puts
itself into
PLAY mode, so I'm happy about that....

NOW THE BAD NEWS: THE COUNTER NO LONGER WORKS.

Instead of "0000" when you first turn the deck on, you see "88_
_" (the
underlines represent the two missing digits).

When you press PLAY the counter DOES NOT change.

When you press REW or FF, the counter briefly shows this:
"8_8_" ...and then
changes to this: "8_ _8" ...and DOES NOT change.

Unless someone has any ideas, I am either going to have to find a
parts deck to
get the proper LM6416E-106 chip, or I am going to have to live without
the counter.

I really wouldn't bother with this deck as I have other Naks that are
much
nicer, but this BX-300 has great sentimental value because it was my
very first
piece of Nak equipment.

DOES ANYONE HAVE ANY IDEAS HOW I CAN CORRECT THE PROBLEM - OR DOES
ANYONE HAVE
ANY SPARE NAKAMICHI IC CHIPS?

THE CHIP THAT CAME OUT OF MY BX-300 HAS THESE MARKINGS ON IT: 106
B-6368A 4F2

Thanks in advance to all who can help me with this!

[William Sommerwerck]

Naive response...

Is it possible that the -106 version (if that, indeed, is what the number
represents) has custom ROM that handles the counter? This is unlikely, but
who knows?

There's also the possibility that, in making repairs, you damaged something
related to counter operation.

[EADGBE]

William:

Not a naive response at all! It turns out that the -106 version does
seem to be a customized version of the LM6416E chip. I did some online
searching, and a couple of electronics wholesalers list part number
LM6416E-106 with manufacturer listed as Nakamichi. So either
Nakamichi manufactured the chip themselves, or the more likely
scenario is that this chip was custom manufactured for Nakamichi.
Aaargh!

On May 27, 12:21 pm, "William Sommerwerck"
> wrote:
> Naive response...
>
> Is it possible that the -106 version (if that, indeed, is what the number
> represents) has custom ROM that handles the counter? This is unlikely, but
> who knows?
>
> There's also the possibility that, in making repairs, you damaged something
> related to counter operation.

[Bob Urz]

EADGBE wrote:
> William:
>
> Not a naive response at all! It turns out that the -106 version does
> seem to be a customized version of the LM6416E chip. I did some online
> searching, and a couple of electronics wholesalers list part number
> LM6416E-106 with manufacturer listed as Nakamichi. So either
> Nakamichi manufactured the chip themselves, or the more likely
> scenario is that this chip was custom manufactured for Nakamichi.
> Aaargh!
>
> On May 27, 12:21 pm, "William Sommerwerck"
> > wrote:
>
>>Naive response...
>>
>>Is it possible that the -106 version (if that, indeed, is what the number
>>represents) has custom ROM that handles the counter? This is unlikely, but
>>who knows?
>>
>>There's also the possibility that, in making repairs, you damaged something
>>related to counter operation.
>
>
>
The LM6413 is just a general purpose 4 bit microprocessor with on board
ram and rom (PDF's are on line). Without the onboard rom programmed, its
totally stupid with no directions to follow. Unless you find the -106
version which has the rom preprogrammed, you would need the firmware and
a programmer to program a blank LM6413 (if that's even possible).

http://www.datasheetarchive.com/pdf/lm6416-datasheet/lm6416-datasheet.html


Before you changed the chip, did you check for proper power supply rail
voltage, ripple, and that any filter caps were not defective?



Bob

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[EADGBE]

Bob:

Thanks for your very informative response. It explained a lot!

Yes, I did thoroughly check all power supply voltages, both at the
power supply circuit and at the IC itself. I checked DC voltage and
AC ripple. All numbers were stable and well within spec. Didn't
check any filter capacitors, though.

On May 27, 2:04 pm, Bob Urz > wrote:
>
> The LM6413 is just a general purpose 4 bit microprocessor with on board
> ram and rom (PDF's are on line). Without the onboard rom programmed, its
> totally stupid with no directions to follow. Unless you find the -106
> version which has the rom preprogrammed, you would need the firmware and
> a programmer to program a blank LM6413 (if that's even possible).
>
> http://www.datasheetarchive.com/pdf/lm6416-datasheet/lm6416-datasheet...
>
> Before you changed the chip, did you check for proper power supply rail
> voltage, ripple, and that any filter caps were not defective?
>
> Bob

[Phil Allison]

"EADGBE"
>
> Not a naive response at all! It turns out that the -106 version does
> seem to be a customized version of the LM6416E chip. I did some online
> searching, and a couple of electronics wholesalers list part number
> LM6416E-106 with manufacturer listed as Nakamichi. So either
> Nakamichi manufactured the chip themselves, or the more likely
> scenario is that this chip was custom manufactured for Nakamichi.
> Aaargh!
>


** The LM6416 is a programmable micro-computer - aka a microcontroller.

Equipment makers purchase them as "blanks" and then program them with the
code needed to do the task in a particular product. The code is invariably
kept secret - so only the equipment maker can supply spare ones.

If the supply of spares dries up or the maker goes out of business like Naka
did, there is no way to get a replacement.




....... Phil

[EADGBE]

I thought as much, Phil. Thanks!

It's funny...I went and Googled "LM6416E-106" and there are TONS of
these sitting around. Unfortunately, they are all in Hong Kong, it
seems! I can get them for $10-$20 apiece plus shipping to the USA,
which brings the price up to 50 or 60 bucks.

I think I'll just wait and get a friend's Nak parts donor deck. His
deck has a digital counter in it as well, very likely powered by the
same IC. And even if it isn't, I'm sure there is something in there I
can use at another time.

[Trevor Wilson]

"EADGBE" > wrote in message
ups.com...
>
> I thought as much, Phil. Thanks!
>
> It's funny...I went and Googled "LM6416E-106" and there are TONS of
> these sitting around. Unfortunately, they are all in Hong Kong, it
> seems! I can get them for $10-$20 apiece plus shipping to the USA,
> which brings the price up to 50 or 60 bucks.

**Good luck with that. Last timne I tried to get some oddball parts, I was
presented with some company in China who ONLY wanted payment via Western
Union (there's a scam right there), or they wanted minimum orders totalling
US$300.00 - $500.00.

>
> I think I'll just wait and get a friend's Nak parts donor deck. His
> deck has a digital counter in it as well, very likely powered by the
> same IC. And even if it isn't, I'm sure there is something in there I
> can use at another time.

**Depends on the deck.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Trevor Wilson]

"EADGBE" > wrote in message
ups.com...
>
> I thought as much, Phil. Thanks!
>
> It's funny...I went and Googled "LM6416E-106" and there are TONS of
> these sitting around. Unfortunately, they are all in Hong Kong, it
> seems! I can get them for $10-$20 apiece plus shipping to the USA,
> which brings the price up to 50 or 60 bucks.

**Good luck with that. Last time I tried to get some oddball parts, I was
presented with some company in China who ONLY wanted payment via Western
Union (there's a scam right there), or they wanted minimum orders totalling
US$300.00 - $500.00.

>
> I think I'll just wait and get a friend's Nak parts donor deck. His
> deck has a digital counter in it as well, very likely powered by the
> same IC. And even if it isn't, I'm sure there is something in there I
> can use at another time.

**Depends on the deck.


--
Trevor Wilson
www.rageaudio.com.au




--
Posted via a free Usenet account from http://www.teranews.com

[Mark]

On May 27, 1:34 pm, EADGBE > wrote:
> Bob:
>
> Thanks for your very informative response. It explained a lot!
>
> Yes, I did thoroughly check all power supply voltages, both at the
> power supply circuit and at the IC itself. I checked DC voltage and
> AC ripple. All numbers were stable and well within spec. Didn't
> check any filter capacitors, though.
>
> On May 27, 2:04 pm, Bob Urz > wrote:
>
>
>
>
>
> > The LM6413 is just a general purpose 4 bit microprocessor with on board
> > ram and rom (PDF's are on line). Without the onboard rom programmed, its
> > totally stupid with no directions to follow. Unless you find the -106
> > version which has the rom preprogrammed, you would need the firmware and
> > a programmer to program a blank LM6413 (if that's even possible).
>
> >http://www.datasheetarchive.com/pdf/lm6416-datasheet/lm6416-datasheet...
>
> > Before you changed the chip, did you check for proper power supply rail
> > voltage, ripple, and that any filter caps were not defective?
>
> > Bob- Hide quoted text -
>
> - Show quoted text -

If I were you, I would put the original chip back in with the correct
programming, then check ALL the input pins for glitches, especilly the
ones that sense the tape movement, how does that part work, is there
an optical sensor or what, check the logic signals from these sensors,
maybe try a 0.1uF cap to ground on each one to remove any glitches,
the switches might be dirty causing the software based counter to
misbehave if it was not designed to have some debouncing feature...

Mark

[William Sommerwerck]

> It's funny... I went and Googled "LM6416E-106" and there are
> TONS of these sitting around. Unfortunately, they are all in
> Hong Kong, it seems! I can get them for $10-$20 apiece plus
> shipping to the USA, which brings the price up to 50 or 60 bucks.

Why should shipping cost so much? This would be shipped as a small packet,
which is only a few dollars.

[Mike Rivers]

On May 28, 10:31 am, "William Sommerwerck"
> wrote:

> Why should shipping cost so much? This would be shipped as a small packet,
> which is only a few dollars.

It's how they make their money on small items, using the excuse that
it's not just the postage, it's the time it takes to prepare the
paperwork, pack it, put a label on it, get it to the post office, and
so on. It's as bad with corporations as it is with home sellers. They
have to account for every penny and every minute.

Haven't you ever bought anything through eBay? A $10 item that weighs
3 ounces ships "anywhere in the US" for $7.49. You could buy it
locally for $14 IF you could buy it locally. But stores ain't what
they used to be and there are so many items that you can only get
through mail order today.

[EADGBE]

Mark:

Your suggestion to put the original chip back in sounds good, but I am
inclined to think that the chip is indeed defective, because when I
installed the "generic" LM6416E chip, two of the main problems went
away: namely, 1) the problem of the deck always returning itself to
PLAY mode even when no tape is inserted (this was the main problem),
and 2) the constantly flickering counter digits.

Even though the generic LM6416E chip could not properly count (due to
lack of Nak-specific programming), the chip DID control the tape
transport functions and counter display voltage perfectly. Thus, I
have to conclude that the original chip is indeed bad.

On May 27, 11:58 pm, Mark > wrote:
>
> If I were you, I would put the original chip back in with the correct
> programming, then check ALL the input pins for glitches, especilly the
> ones that sense the tape movement, how does that part work, is there
> an optical sensor or what, check the logic signals from these sensors,
> maybe try a 0.1uF cap to ground on each one to remove any glitches,
> the switches might be dirty causing the software based counter to
> misbehave if it was not designed to have some debouncing feature...
>
> Mark

[Scott Dorsey]

EADGBE > wrote:
>First of all, I have narrowed it down to IC701 on the counter PC
>board. This IC
>chip (microprocessor) apparently was faulty.
>
>In the Nakamichi service manual, this chip is listed as LM6416E-106

This is a microcontroller that has Nakamichi software in it.

>I found an LM6416E at an online parts source that caters to repair
>techs. There was no suffix of any kind
>after the "E". It is just a "regular" LM6416E. I thought this IC was
>the same
>as the faulty one in the BX-300, but it's not.

It has different software in it.

>Unless someone has any ideas, I am either going to have to find a
>parts deck to
>get the proper LM6416E-106 chip, or I am going to have to live without
>the counter.

The counters on these decks aren't really very accurate anyway, to be honest.

>I really wouldn't bother with this deck as I have other Naks that are
>much
>nicer, but this BX-300 has great sentimental value because it was my
>very first
>piece of Nak equipment.
>
>DOES ANYONE HAVE ANY IDEAS HOW I CAN CORRECT THE PROBLEM - OR DOES
>ANYONE HAVE
>ANY SPARE NAKAMICHI IC CHIPS?

It may be possible to clone the firmware if you can borrow a good one
from another machine.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[EADGBE]

On May 29, 10:56 am, (Scott Dorsey) wrote:
>
> It may be possible to clone the firmware if you can borrow a good one
> from another machine.
> --scott

Scott:

Actually, a friend has a CR3a deck that has the exact same IC chip in
it. How would I clone the firmware from his chip to re-program my
faulty chip?

[William Sommerwerck]

> A friend has a CR3A deck that has the same chip.
> How would I clone the firmware from his chip to
> re-program my faulty chip?

With a PROM burner (or similar product) designed for that purpose. Good luck
finding one.

If I still worked for Data I/O, I'd try to help you -- that's what they
make.

By the way, you'd probably need a new, clean chip. It's unlikely the
microprocessor is re-programmable.

[Scott Dorsey]

EADGBE > wrote:
>
>Actually, a friend has a CR3a deck that has the exact same IC chip in
>it. How would I clone the firmware from his chip to re-program my
>faulty chip?

You'll need to get the manufacturer's data sheet for the microcontroller,
which will tell you. Odds are you can get a blank microcontroller, and a
PROM burner with the correct pod on it. Some manufacturers make special
microcontrollers for prototyping purposes, which take a piggyback EPROM.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Phil Allison]

"EADGBE" = top posting IDIOT

> Your suggestion to put the original chip back in sounds good, but I am
> inclined to think that the chip is indeed defective, because when I
> installed the "generic" LM6416E chip,


** There is no such thing - you fool.

It is either a blank and so does NOTHING at all or it has a specific
purpose programmed in.


> two of the main problems went
> away: namely, 1) the problem of the deck always returning itself to
> PLAY mode even when no tape is inserted (this was the main problem),
> and 2) the constantly flickering counter digits.


** So it was simply not working.


> Even though the generic LM6416E chip could not properly count (due to
> lack of Nak-specific programming), the chip DID control the tape
> transport functions and counter display voltage perfectly.


** ******** - it simply did nothing.


> Thus, I
> have to conclude that the original chip is indeed bad.


** Like a hee hawing ass makes a conclusion.



....... Phil

[Phil Allison]

"Scott Dorsey" <
> EADGBE
>>
>>Actually, a friend has a CR3a deck that has the exact same IC chip in
>>it. How would I clone the firmware from his chip to re-program my
>>faulty chip?
>
> You'll need to get the manufacturer's data sheet for the microcontroller,
> which will tell you.


** ROTFL !!

Dorsey is a brain dead ASS !!



......... Phil

[Gareth Magennis]

"EADGBE" > wrote in message
oups.com...
> On May 29, 10:56 am, (Scott Dorsey) wrote:
>>
>> It may be possible to clone the firmware if you can borrow a good one
>> from another machine.
>> --scott
>
> Scott:
>
> Actually, a friend has a CR3a deck that has the exact same IC chip in
> it. How would I clone the firmware from his chip to re-program my
> faulty chip?
>
>


You would need to make a substantial investment in a Programming system -
several hundred dollars - it would be a lot cheaper to buy another used
Nakamichi.

Also, some uControllers have one time programmable Program Memory so you
would need to buy a new blank chip, some have protection systems that
prevent the code being read so you may not be able to clone it anyway (this
is an optional programming tool that can be used at will). You won't know
that til you've spent your several hundred dollars and given it a go, though
the datasheet might give you more info on whether this particular chip has
this facility, the one I found has little detailed information.





Gareth.

[EADGBE]

"Phil Allison" = childish, name-calling troll - one of millions who
fire off what they think are clever

On May 29, 11:28 pm, "Phil Allison" > wrote:
> "Phil Allison" = top posting IDIOT
>
> > Your suggestion to put the original chip back in sounds good, but I am
> > inclined to think that the chip is indeed defective, because when I
> > installed the "generic" LM6416E chip,
>
> ** There is no such thing - you fool.

That is why I used the word "generic" in QUOTATION MARKS - you fool.
If your reading comprehension skills had been above primary-school
level, you would have been able to comprehend that I was contrasting
the purpose-programmed LM6416E chip that was factory installed into my
BX-300, and the regular-issue LM6416E I had purchased, which did not
have the tape counter programming specific to my deck's application.


> It is either a blank and so does NOTHING at all or it has a specific
> purpose programmed in.
>
> > two of the main problems went
> > away: namely, 1) the problem of the deck always returning itself to
> > PLAY mode even when no tape is inserted (this was the main problem),
> > and 2) the constantly flickering counter digits.
>
> ** So it was simply not working.

Don't jump to a conclusion so fast, lest you find yourself compared to
a "hee-hawing ass" -- whoops, too late.

The deck's original LM6416E did work most of the time, but at certain
times worked intermittently. Most of the time, it worked flawlessly,
but at certain random times when the deck was left on for more than 30
minutes, it would not operate the tape counter properly, and it would
also return the deck to PLAY mode at random times, no matter what
other operation mode was in effect (RW, FF, STOP). So it was not a
clear-cut case of outright failure, as you seem to think. In fact,
the deck could still work well enough -- the only real reason I want
to replace the original chip at all is down to getting rid of a
nuisance situation. (Wish I could get rid of ALL nuisances....hint,
hint)


> > Even though the generic LM6416E chip could not properly count (due to
> > lack of Nak-specific programming), the chip DID control the tape
> > transport functions and counter display voltage perfectly.
>
> ** ******** - it simply did nothing.

Here is where your tendency to fling yourself toward a conclusion has
really screwed you up. Do you know anything about the circuitry of
the Nakamichi BX-300, or any other Nakamichi deck...or possibly even
any electronic device at all?

The LM6416E chip controls the counter and works with the Logic circuit
on the main PCB to control the deck's tape transport functions. When
I replaced the LM6416E chip, two of the deck's problems (always
returning to PLAY mode, flickering digits in the counter display) were
cured. Therefore, the new LM6416E actually DID do something. The
empirical evidence is right there. I was once again able to control
the deck's tape transport functions with absolutely no problems
whatsoever.

I can't really see why you have a problem with that...or did you just
want to pretend to be a grown-up and use the word "********" in a
post? Careful now, don't let Mum see you use that language! LOL


> > Thus, I
> > have to conclude that the original chip is indeed bad.
>
> ** Like a hee hawing ass makes a conclusion.
>
> ...... Phil

The irony of your attempt to be clever here should be evident to
everyone (except yourself, of course).

I will waste no more time with you. Go ahead and conjure up some more
childish retorts from the safety of your parent's cellar. I won't
take the bait. Good riddance, and have a nice day!

[Phil Allison]

"EADGBE" = Top Posting ****ing IDIOT


> Your suggestion to put the original chip back in sounds good, but I am
> inclined to think that the chip is indeed defective, because when I
> installed the "generic" LM6416E chip,


** There is NO such thing - you fool.

It is either a *blank * and so does ** NOTHING ** at all or it has a
specific purpose programmed in.

YOU have no comprehension of what a micro-controller IS !!!!!



> two of the main problems went
> away: namely, 1) the problem of the deck always returning itself to
> PLAY mode even when no tape is inserted (this was the main problem),
> and 2) the constantly flickering counter digits.


** So it was simply not working.


YOU have no comprehension of what a micro-controller IS !!!!!


> Even though the generic LM6416E chip could not properly count (due to
> lack of Nak-specific programming), the chip DID control the tape
> transport functions and counter display voltage perfectly.


** ******** - it simply did nothing.

YOU have no comprehension of what a micro-controller IS !!!!!


> Thus, I
> have to conclude that the original chip is indeed bad.


** Like a hee hawing ass makes a conclusion.

**** OFF !!!!!



....... Phil

[No Name]

In rec.audio.pro Gareth Magennis > wrote:
>
> "EADGBE" > wrote in message
> oups.com...
>> On May 29, 10:56 am, (Scott Dorsey) wrote:
>>>
>>> It may be possible to clone the firmware if you can borrow a good one
>>> from another machine.
>>> --scott
>>
>> Scott:
>>
>> Actually, a friend has a CR3a deck that has the exact same IC chip in
>> it. How would I clone the firmware from his chip to re-program my
>> faulty chip?
>>
>>
>
>
> You would need to make a substantial investment in a Programming system -
> several hundred dollars - it would be a lot cheaper to buy another used
> Nakamichi.

You can buy used PROM burners cheap as all get out.

--
Aaron

[Scott Dorsey]

> wrote:
>
>You can buy used PROM burners cheap as all get out.

Right, it's the programming pods that are the issue these days. Unless you
want to burn 2716s or something.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Gareth Magennis]

"Scott Dorsey" > wrote in message
...
> > wrote:
>>
>>You can buy used PROM burners cheap as all get out.
>
> Right, it's the programming pods that are the issue these days. Unless
> you
> want to burn 2716s or something.
> --scott
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."




Yes, this is not a common part like a PIC or an 8051 based device, where you
could get a programmer and maybe read and write to it. PROM burners have to
know exactly which device they are dealing with, and have the hardware and
software capable of doing so. Its a bit like saying "I've got a computer so
I should be able to connect it to my BMW and reset the mileage".



Gareth.