Tascam MS-16 diode

Tascam MS-16 diode
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My Tascam MS-16 seems to have the zener diode problem perfectly
described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


I'd like to replace the diode to see if that fixes the problem,

but I
don't have a service manual yet. Does anyone have a manual for

sale,
or know someplace that will sell one? Otherwise, if there are

other
MS-16 owners who already know the proper diode value (for R15,

with a
marking of 1961R) I'd love a little advice if you can spare it!

I've
searched the web for that marking and come up empty. That may

very
well be due to my lack of skill and familiarity with electronics.

Thanks for any help or leads you can provide!

-Chris

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JP Gerard View profile
More options Jan 14 2007, 10:50 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Wed, 14 Jan 2007 17:51:03 +0100
Local: Wed, Jan 14 2007 10:51 am
Subject: Re: Tascam MS-16 diode prob. (?)
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D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes the erase

head
circuit (one side of the relay to erase head neg. terminal, one

side to
ground) so unless it's closed, you can't have any current flowing

through
the erase head.
After I replaced all the relays with Omrons, no more funky

erasure...


But if the circuit driving the relay starts acting funky, it can

indeed be a
problem.


After about 10 years, you should consider replacing all the parts

that are
prone to aging issues.
I recapped the whole tyhing which took a lot of time and sweat,

but it was
worth it.


I'm now going to remove all the cards again and float those

Zeners above the
PCB surface, thanks for the tip!


JP


"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le message

de news:
a513981.0401140753.75be4...@posting.google.com...

My Tascam MS-16 seems to have the zener diode problem perfectly
described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...
tput=gplain


- Hide quoted text -
- Show quoted text -

I'd like to replace the diode to see if that fixes the problem,

but I

don't have a service manual yet. Does anyone have a manual for

sale,

or know someplace that will sell one? Otherwise, if there are

other

MS-16 owners who already know the proper diode value (for R15,

with a

marking of 1961R) I'd love a little advice if you can spare it!

I've

searched the web for that marking and come up empty. That may

very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

Reply Reply to author Forward Rate this post:

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JP Gerard View profile
More options Jan 14 2007, 10:52 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Wed, 14 Jan 2007 17:54:41 +0100
Local: Wed, Jan 14 2007 10:54 am
Subject: Re: Tascam MS-16 diode prob. (?)
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Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!


JP


"JP Gerard" <jpgerard@skynet> a écrit dans le message de news:

....



- Hide quoted text -
- Show quoted text -

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes the

erase head

circuit (one side of the relay to erase head neg. terminal, one

side to

ground) so unless it's closed, you can't have any current

flowing through

the erase head.
After I replaced all the relays with Omrons, no more funky

erasure...

But if the circuit driving the relay starts acting funky, it

can indeed be
a

problem.

After about 10 years, you should consider replacing all the

parts that are

prone to aging issues.
I recapped the whole tyhing which took a lot of time and sweat,

but it was

worth it.

I'm now going to remove all the cards again and float those

Zeners above
the

PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de news:

a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


- Hide quoted text -
- Show quoted text -

tput=gplain

I'd like to replace the diode to see if that fixes the

problem, but I

don't have a service manual yet. Does anyone have a manual

for sale,

or know someplace that will sell one? Otherwise, if there

are other

MS-16 owners who already know the proper diode value (for

R15, with a

marking of 1961R) I'd love a little advice if you can spare

it! I've

searched the web for that marking and come up empty. That

may very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

Reply Reply to author Forward Rate this post:

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JP Gerard View profile
More options Jan 14 2007, 11:18 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Wed, 14 Jan 2007 18:20:30 +0100
Local: Wed, Jan 14 2007 11:20 am
Subject: Re: Tascam MS-16 diode prob. (?)
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And the D15 diodes in my MS16 are marked:

19 - 61R


The 6V Zeners are marked:


06 - 61R


So... Is D15 a 19V zener after all?


Help?


JP


"JP Gerard" <jpgerard@skynet> a écrit dans le message de news:
40058184$0$6084$ba620...@news.skynet.be...



- Hide quoted text -
- Show quoted text -

Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de news:

....

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes the

erase head

circuit (one side of the relay to erase head neg. terminal,

one side to

ground) so unless it's closed, you can't have any current

flowing
through

the erase head.
After I replaced all the relays with Omrons, no more funky

erasure...

But if the circuit driving the relay starts acting funky, it

can indeed
be

a
problem.

After about 10 years, you should consider replacing all the

parts that
are

prone to aging issues.
I recapped the whole tyhing which took a lot of time and

sweat, but it
was

worth it.

I'm now going to remove all the cards again and float those

Zeners above

the
PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de
news:

a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


- Hide quoted text -
- Show quoted text -

tput=gplain

I'd like to replace the diode to see if that fixes the

problem, but I

don't have a service manual yet. Does anyone have a manual

for sale,

or know someplace that will sell one? Otherwise, if there

are other

MS-16 owners who already know the proper diode value (for

R15, with a

marking of 1961R) I'd love a little advice if you can spare

it! I've

searched the web for that marking and come up empty. That

may very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

Reply Reply to author Forward Rate this post:

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Chris Lynch View profile
More options Jan 14 2007, 9:17 pm

Newsgroups: rec.audio.pro
From: ch...@choochoolarouge.com (Chris Lynch)
Date: 14 Jan 2007 19:17:57 -0800
Local: Wed, Jan 14 2007 9:17 pm
Subject: Re: Tascam MS-16 diode prob. (?)
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Hi JP,

That's great info, thanks! I'm really not sure how to test if

it's
the relays, so I figured it's cheaper to swap the diode first,

and if
it still erases I'll hit the relays next.


As for the voltage:

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

....does that come from the service manual? If so, do we need to

worry
about the voltage as long as we get the right part#? I just

checked
jameco.com and mouser.com and I'm having no luck, and I can't

even
find components on tascam.com, so I clearly don't know what I'm

doing.

-Chris



- Hide quoted text -
- Show quoted text -

"JP Gerard" <jpgerard@skynet> wrote in message

<news:400579cf$0$1156$ba620e4c@news.skynet.be>...

And the D15 diodes in my MS16 are marked:

19 - 61R

The 6V Zeners are marked:

06 - 61R

So... Is D15 a 19V zener after all?

Help?

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de news:
40058184$0$6084$ba620...@news.skynet.be...
Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news: ...

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes the

erase head

circuit (one side of the relay to erase head neg. terminal,

one side to

ground) so unless it's closed, you can't have any current

flowing

through
the erase head.
After I replaced all the relays with Omrons, no more funky

erasure...

But if the circuit driving the relay starts acting funky,

it can indeed

be
a
problem.

After about 10 years, you should consider replacing all the

parts that

are
prone to aging issues.
I recapped the whole tyhing which took a lot of time and

sweat, but it

was
worth it.

I'm now going to remove all the cards again and float those

Zeners above

the
PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de

news:
a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...

tput=gplain

I'd like to replace the diode to see if that fixes the

problem, but I

don't have a service manual yet. Does anyone have a

manual for sale,

or know someplace that will sell one? Otherwise, if

there are other

MS-16 owners who already know the proper diode value (for

R15, with a

marking of 1961R) I'd love a little advice if you can

spare it! I've

searched the web for that marking and come up empty.

That may very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

Reply Reply to author Forward Rate this post:

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JP Gerard View profile
More options Jan 15 2007, 10:19 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Thu, 15 Jan 2007 17:21:45 +0100
Local: Thurs, Jan 15 2007 10:21 am
Subject: Re: Tascam MS-16 diode prob. (?)
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That's great info, thanks! I'm really not sure how to test if

it's

the relays, so I figured it's cheaper to swap the diode first,

and if

it still erases I'll hit the relays next.

Absolutely, actually I'm looking forward to having all the D15

replaced.
Having a hard time finding high dissipation 19V Zener diodes

though... up to
18, no prob, then it's 20, 22, 24V etc. It's a reference voltage

so it has
to be a 19V zener for proper operation.

As for the voltage:
D15: EQA01-09R 9V Zener Tascam P/N 5143174000
...does that come from the service manual? If so, do we need

to worry

about the voltage as long as we get the right part#? I just

checked

jameco.com and mouser.com and I'm having no luck, and I can't

even

find components on tascam.com, so I clearly don't know what I'm

doing.

-Chris

Sure, you should order a copy from Tascam. I got my MS16 in shape

but
without the manual it would've taken so much guess work...
Ordering the part from tascam is a solution, but I usually overdo

things and
I'm thinking about a 5W Zener here... why not?
Call your local Tascam rep., if I was able to ask my local rep.

(I'm in
Belgium) about parts for my 38 and my MS16, you should be able to

as well.

JP

"JP Gerard" <jpgerard@skynet> wrote in message

<news:400579cf$0$1156$ba620e4c@news.skynet.be>...


- Hide quoted text -
- Show quoted text -

And the D15 diodes in my MS16 are marked:

19 - 61R

The 6V Zeners are marked:

06 - 61R

So... Is D15 a 19V zener after all?

Help?

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news:

40058184$0$6084$ba620...@news.skynet.be...
Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news: ...

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes

the erase
head

circuit (one side of the relay to erase head neg.

terminal, one side
to

ground) so unless it's closed, you can't have any current

flowing

through
the erase head.
After I replaced all the relays with Omrons, no more

funky
erasure...

But if the circuit driving the relay starts acting funky,

it can
indeed

be
a
problem.

After about 10 years, you should consider replacing all

the parts
that

are
prone to aging issues.
I recapped the whole tyhing which took a lot of time and

sweat, but
it

was
worth it.

I'm now going to remove all the cards again and float

those Zeners
above

the
PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de

news:
a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


- Hide quoted text -
- Show quoted text -

tput=gplain

I'd like to replace the diode to see if that fixes the

problem,
but I

don't have a service manual yet. Does anyone have a

manual for
sale,

or know someplace that will sell one? Otherwise, if

there are
other

MS-16 owners who already know the proper diode value

(for R15,
with a

marking of 1961R) I'd love a little advice if you can

spare it!
I've

searched the web for that marking and come up empty.

That may
very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

Reply Reply to author Forward Rate this post:

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Justin Ulysses Morse View profile
JP Gerard <jpgerard@skynet> wrote: > Absolutely, actually I'm

looking forward to having all the D15 replaced. > Having a hard

time finding high dissipation 19V Zener diodes though... up to >

18, no prob, then it's 20, 22, 24V etc. It's a reference voltage

so it has > to be a 19V zener for proper operation. > > As for

the voltage: > > > > > D15: EQA01-09R 9V Zener Tascam P/N

5143174000 > > ...does that come from the service manual? If so,

do we need to worry > > about the voltage as long as we get the

right part#? > Sure, you should order a copy from Tascam. I got

my MS16 in shape but > without the manual it would've taken so

much guess work... > Ordering the part from tascam is a solution,

but I usually overdo things and > I'm thinking about a 5W Zener

here... why not? > Call your local Tascam rep., if I was able to

ask my local rep. (I'm in > Belgium) about parts for my 38 and my

MS16, you should be able to as well. You should look for a

replacement zener that has the same package size and the same

power rating as the original. The same package size will assure

that it'll still fit on the circuitboard, and the same power

rating will assure that the voltage is spot on. Zener voltage is

specified at some particular reference current, and larger diodes

would presumably have a higher reference current. So using a 5W

zener in place of a 0.5W zener could, theoretically, have some

impact on the effective reference voltage. I don't know the

circuit you're dealing with so I don't know how important it is.

Digi-Key lists 19V zeners in DO-35 (0.5W), DO-41 (2W), and T-18

(5W) packages I would bet you want the DO-41. It's Digikey part

# 2EZ19D5MSCT-ND and they cost $0.75 apiece. ulysses - Hide

quoted text -- Show quoted text -
More options Jan 16 2007, 12:40 am

Newsgroups: rec.audio.pro
From: Justin Ulysses Morse <ulyssesnos...@rollmusic.com>
Date: Fri, 16 Jan 2007 00:40:46 -0600
Local: Fri, Jan 16 2007 12:40 am
Subject: Re: Tascam MS-16 diode prob. (?)
Reply to author | Forward | Print | Individual message | Show

original | Report this message | Find messages by this author


- Hide quoted text -
- Show quoted text -

JP Gerard <jpgerard@skynet> wrote:

Absolutely, actually I'm looking forward to having all the D15

replaced.

Having a hard time finding high dissipation 19V Zener diodes

though... up to

18, no prob, then it's 20, 22, 24V etc. It's a reference

voltage so it has

to be a 19V zener for proper operation.

As for the voltage:
D15: EQA01-09R 9V Zener Tascam P/N 5143174000
...does that come from the service manual? If so, do we need

to worry

about the voltage as long as we get the right part#?

Sure, you should order a copy from Tascam. I got my MS16 in

shape but

without the manual it would've taken so much guess work...
Ordering the part from tascam is a solution, but I usually

overdo things and

I'm thinking about a 5W Zener here... why not?
Call your local Tascam rep., if I was able to ask my local rep.

(I'm in

Belgium) about parts for my 38 and my MS16, you should be able

to as well.



You should look for a replacement zener that has the same package

size
and the same power rating as the original. The same package size

will
assure that it'll still fit on the circuitboard, and the same

power
rating will assure that the voltage is spot on. Zener voltage is
specified at some particular reference current, and larger diodes

would
presumably have a higher reference current. So using a 5W zener

in
place of a 0.5W zener could, theoretically, have some impact on

the
effective reference voltage. I don't know the circuit you're

dealing
with so I don't know how important it is.

Digi-Key lists 19V zeners in DO-35 (0.5W), DO-41 (2W), and T-18

(5W)
packages I would bet you want the DO-41. It's Digikey part #
2EZ19D5MSCT-ND and they cost $0.75 apiece.


ulysses




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JP Gerard View profile
More options Jan 16 2007, 4:12 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Fri, 16 Jan 2007 11:14:14 +0100
Local: Fri, Jan 16 2007 4:14 am
Subject: Re: Tascam MS-16 diode prob. (?)
Reply to author | Forward | Print | Individual message | Show

original | Report this message | Find messages by this author

You should look for a replacement zener that has the same

package size

and the same power rating as the original. The same package

size will

assure that it'll still fit on the circuitboard, and the same

power

rating will assure that the voltage is spot on. Zener voltage

is

specified at some particular reference current, and larger

diodes would

presumably have a higher reference current. So using a 5W

zener in

place of a 0.5W zener could, theoretically, have some impact on

the

effective reference voltage. I don't know the circuit you're

dealing

with so I don't know how important it is.

But wouldn't you expect the manufaturer specified Zener V to be

spot on,
regardless of the power rating?
But sure, a 2W would probably be plenty. I'm still trying to find

the
original diode's power rating though.
The diode will be floating about 1/2" off the PCB so size is not

too
important.

Digi-Key lists 19V zeners in DO-35 (0.5W), DO-41 (2W), and T-18

(5W)

packages I would bet you want the DO-41. It's Digikey part #
2EZ19D5MSCT-ND and they cost $0.75 apiece.

Cool, thanks!

JP




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JP Gerard View profile
More options Jan 16 2007, 9:33 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Fri, 16 Jan 2007 16:35:41 +0100
Local: Fri, Jan 16 2007 9:35 am
Subject: Re: Tascam MS-16 diode prob. (?)
Reply to author | Forward | Print | Individual message | Show

original | Report this message | Find messages by this author
And I was just told by my local rep. that a 3W Zener floating

around 1/2"
from the board will work well.

I'm definitely doing the mod ASAP.


JP


"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le message

de news:
a513981.0401141917.263d4...@posting.google.com...



- Hide quoted text -
- Show quoted text -

Hi JP,

That's great info, thanks! I'm really not sure how to test if

it's

the relays, so I figured it's cheaper to swap the diode first,

and if

it still erases I'll hit the relays next.

As for the voltage:

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

...does that come from the service manual? If so, do we need

to worry

about the voltage as long as we get the right part#? I just

checked

jameco.com and mouser.com and I'm having no luck, and I can't

even

find components on tascam.com, so I clearly don't know what I'm

doing.

-Chris

"JP Gerard" <jpgerard@skynet> wrote in message

<news:400579cf$0$1156$ba620e4c@news.skynet.be>...


- Hide quoted text -
- Show quoted text -

And the D15 diodes in my MS16 are marked:

19 - 61R

The 6V Zeners are marked:

06 - 61R

So... Is D15 a 19V zener after all?

Help?

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news:

40058184$0$6084$ba620...@news.skynet.be...
Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news: ...

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes

the erase
head

circuit (one side of the relay to erase head neg.

terminal, one side
to

ground) so unless it's closed, you can't have any current

flowing

through
the erase head.
After I replaced all the relays with Omrons, no more

funky
erasure...

But if the circuit driving the relay starts acting funky,

it can
indeed

be
a
problem.

After about 10 years, you should consider replacing all

the parts
that

are
prone to aging issues.
I recapped the whole tyhing which took a lot of time and

sweat, but
it

was
worth it.

I'm now going to remove all the cards again and float

those Zeners
above

the
PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de

news:
a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


- Hide quoted text -
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tput=gplain

I'd like to replace the diode to see if that fixes the

problem,
but I

don't have a service manual yet. Does anyone have a

manual for
sale,

or know someplace that will sell one? Otherwise, if

there are
other

MS-16 owners who already know the proper diode value

(for R15,
with a

marking of 1961R) I'd love a little advice if you can

spare it!
I've

searched the web for that marking and come up empty.

That may
very

well be due to my lack of skill and familiarity with

electronics.

Thanks for any help or leads you can provide!

-Chris

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JP Gerard View profile
More options Jan 16 2007, 9:34 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Fri, 16 Jan 2007 16:37:01 +0100
Local: Fri, Jan 16 2007 9:37 am
Subject: Re: Tascam MS-16 diode prob. (?)
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Ahem, meant a 20V 3W Zener...

But 19V will work too, of course...


JP


"JP Gerard" <jpgerard@skynet> a écrit dans le message de news:
4008043a$0$778$ba620...@news.skynet.be...



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And I was just told by my local rep. that a 3W Zener floating

around 1/2"

from the board will work well.

I'm definitely doing the mod ASAP.

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans le

message de news:

a513981.0401141917.263d4...@posting.google.com...
Hi JP,

That's great info, thanks! I'm really not sure how to test

if it's

the relays, so I figured it's cheaper to swap the diode

first, and if

it still erases I'll hit the relays next.

As for the voltage:

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

...does that come from the service manual? If so, do we need

to worry

about the voltage as long as we get the right part#? I just

checked

jameco.com and mouser.com and I'm having no luck, and I can't

even

find components on tascam.com, so I clearly don't know what

I'm doing.

-Chris

"JP Gerard" <jpgerard@skynet> wrote in message
news:400579cf$0$1156$ba620e4c@news.skynet.be>...
And the D15 diodes in my MS16 are marked:

19 - 61R

The 6V Zeners are marked:

06 - 61R

So... Is D15 a 19V zener after all?

Help?

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news:

40058184$0$6084$ba620...@news.skynet.be...
Ah, the schemo says 19V Zener...

Must be a 9V though, the rail is 15V!

JP

"JP Gerard" <jpgerard@skynet> a écrit dans le message de

news: ...

D15: EQA01-09R 9V Zener Tascam P/N 5143174000

Unless K2 is activated, you're safe. Half of K2 closes

the erase

head
circuit (one side of the relay to erase head neg.

terminal, one
side

to
ground) so unless it's closed, you can't have any

current flowing

through
the erase head.
After I replaced all the relays with Omrons, no more

funky

erasure...

But if the circuit driving the relay starts acting

funky, it can

indeed
be
a
problem.

After about 10 years, you should consider replacing all

the parts

that
are
prone to aging issues.
I recapped the whole tyhing which took a lot of time

and sweat,
but

it
was
worth it.

I'm now going to remove all the cards again and float

those Zeners

above
the
PCB surface, thanks for the tip!

JP

"Chris Lynch" <ch...@choochoolarouge.com> a écrit dans

le message
de

news:
a513981.0401140753.75be4...@posting.google.com...
My Tascam MS-16 seems to have the zener diode problem

perfectly

described in this post:

http://groups.google.com/groups?selm=3rtdhs%24psc%40newsbf02.news

..aol...


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tput=gplain

I'd like to replace the diode to see if that fixes

the problem,

but I
don't have a service manual yet. Does anyone have a

manual for

sale,
or know someplace that will sell one? Otherwise, if

there are

other
MS-16 owners who already know the proper diode value

(for R15,

with a
marking of 1961R) I'd love a little advice if you can

spare it!

I've
searched the web for that marking and come up empty.

That may

very
well be due to my lack of skill and familiarity with
electronics.

Thanks for any help or leads you can provide!

-Chris

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Discussion subject changed to "Tascam MS-16 diodes found, still

need gas relays" by Chris Lynch








Chris Lynch View profile
More options Jan 16 2007, 11:49 am

Newsgroups: rec.audio.pro
From: ch...@choochoolarouge.com (Chris Lynch)
Date: 16 Jan 2007 09:49:40 -0800
Local: Fri, Jan 16 2007 11:49 am
Subject: Re: Tascam MS-16 diodes found, still need gas relays
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I finally found out how to contact Tascam after fumbling around

their
website for a while, here's the info:

Mark V Electronics, Inc. ,
8019 E. Slauson Avenue , Montebello, CA 90640 , ,

http://www.markvelectronics.com , Tel: 800-423-FIVE (orders

outside Canada) , 800-521-MARK (orders in Canada) , 213-888-8988

(catalog/info) Fax: 213-888-6868 ,

They responded to my e-mail with this:


"The diodes, part number 5224544601, is available at $.55 cents

each.
The relays, p/n 5290010400, is available at $13.40 each. Please

add $4
for postage/freight per order for UPS ground service within
CONTINENTAL USA plus local and state sales taxes where

applicable.
Prices quoted are only for SHIPMENT WITHIN THE U.S. or its
territories."


I bought the diodes and a service manual and the whole thing is

around
$60 USD from Tascam because I just don't trust myself to use a
different diode, and this'll just be easier. I asked if those

relays
were the gas filled ones, but he didn't think so. Where would I

find
those? Note that the diode part number has changed.


Thanks for all the info, and I hope this helps!


-Chris



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"JP Gerard" <jpgerard@skynet> wrote in message

<news:4007b8e0$0$321$ba620e4c@news.skynet.be>...

You should look for a replacement zener that has the same

package size

and the same power rating as the original. The same package

size will

assure that it'll still fit on the circuitboard, and the same

power

rating will assure that the voltage is spot on. Zener

voltage is

specified at some particular reference current, and larger

diodes would

presumably have a higher reference current. So using a 5W

zener in

place of a 0.5W zener could, theoretically, have some impact

on the

effective reference voltage. I don't know the circuit you're

dealing

with so I don't know how important it is.

But wouldn't you expect the manufaturer specified Zener V to be

spot on,

regardless of the power rating?
But sure, a 2W would probably be plenty. I'm still trying to

find the

original diode's power rating though.
The diode will be floating about 1/2" off the PCB so size is

not too

important.

Digi-Key lists 19V zeners in DO-35 (0.5W), DO-41 (2W), and

T-18 (5W)

packages I would bet you want the DO-41. It's Digikey part

#

2EZ19D5MSCT-ND and they cost $0.75 apiece.

Cool, thanks!

JP

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JP Gerard View profile
More options Jan 16 2007, 12:11 pm

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Fri, 16 Jan 2007 19:13:51 +0100
Local: Fri, Jan 16 2007 12:13 pm
Subject: Re: Tascam MS-16 diodes found, still need gas relays
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original | Report this message | Find messages by this author

"The diodes, part number 5224544601, is available at $.55 cents

each.

The relays, p/n 5290010400, is available at $13.40 each. Please

add $4

for postage/freight per order for UPS ground service within
CONTINENTAL USA plus local and state sales taxes where

applicable.

Prices quoted are only for SHIPMENT WITHIN THE U.S. or its
territories."

Wow, buy Omron Relays, they're cheaper and much better.

I bought the diodes and a service manual and the whole thing is

around

$60 USD from Tascam because I just don't trust myself to use a
different diode, and this'll just be easier. I asked if those

relays

were the gas filled ones, but he didn't think so. Where would

I find

those? Note that the diode part number has changed.

Sounds about right.
You'll learn a LOT from that manual.
The big electronics parts suppliers will have 24V Relays in

stock, no prob.

Thanks for all the info, and I hope this helps!
-Chris

Hey, thanks for pointig out the problem.
I'll do the mod next week and keep you posted, but I don't expect

anything
spectacular.
Just solid, reliable operation would be good...

JP

"JP Gerard" <jpgerard@skynet> wrote in message

<news:4007b8e0$0$321$ba620e4c@news.skynet.be>...


- Hide quoted text -
- Show quoted text -

You should look for a replacement zener that has the same

package size

and the same power rating as the original. The same

package size will

assure that it'll still fit on the circuitboard, and the

same power

rating will assure that the voltage is spot on. Zener

voltage is

specified at some particular reference current, and larger

diodes
would

presumably have a higher reference current. So using a 5W

zener in

place of a 0.5W zener could, theoretically, have some

impact on the

effective reference voltage. I don't know the circuit

you're dealing

with so I don't know how important it is.

But wouldn't you expect the manufaturer specified Zener V to

be spot on,

regardless of the power rating?
But sure, a 2W would probably be plenty. I'm still trying to

find the

original diode's power rating though.
The diode will be floating about 1/2" off the PCB so size is

not too

important.

Digi-Key lists 19V zeners in DO-35 (0.5W), DO-41 (2W), and

T-18 (5W)

packages I would bet you want the DO-41. It's Digikey

part #

2EZ19D5MSCT-ND and they cost $0.75 apiece.

Cool, thanks!

JP

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Discussion subject changed to "Tascam MS-16 diode prob. (?)" by

Justin Ulysses Morse








Justin Ulysses Morse View profile
More options Jan 16 2007, 4:59 pm

Newsgroups: rec.audio.pro
From: Justin Ulysses Morse <ulyssesnos...@rollmusic.com>
Date: Fri, 16 Jan 2007 16:59:06 -0600
Local: Fri, Jan 16 2007 4:59 pm
Subject: Re: Tascam MS-16 diode prob. (?)
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JP Gerard <jpgerard@skynet> wrote:

But wouldn't you expect the manufaturer specified Zener V to be

spot on,

regardless of the power rating?

It'll only be spot-on if it has the specified amount of current

going
through it. It'll probably be very close anyway though.

But sure, a 2W would probably be plenty. I'm still trying to

find the

original diode's power rating though.
The diode will be floating about 1/2" off the PCB so size is

not too

important.

It's the length that you have to look at. A DO-35 package uses a

pin
spacing of 0.3" while a DO-41 package uses 0.4". Those 5W T-18
packages are probably longer. You can pretty much tell the power
rating by the package size, too. 500mW zeners are in a DO-35

package
while 2W zeners are DO-41. So measure the pin spacing on the
circuitboard and you'll know which diode to order.

ulysses




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Discussion subject changed to "Tascam MS-16 diodes found, still

need gas relays" by Scott Dorsey








Scott Dorsey View profile
Chris Lynch <ch...@choochoolarouge.com> wrote: >"The diodes, part

number 5224544601, is available at $.55 cents each. >The relays,

p/n 5290010400, is available at $13.40 each. Please add $4 >for

postage/freight per order for UPS ground service within

CONTINENTAL USA plus local and state sales taxes where

applicable. >Prices quoted are only for SHIPMENT WITHIN THE U.S.

or its >territories." Don't use the original replacement relays!

They will just go bad again... I think there is an Omron in the

Digi-Key catalogue with gold contacts and an identical pinout.

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


More options Jan 19 2007, 9:32 pm

Newsgroups: rec.audio.pro
From: klu...@panix.com (Scott Dorsey)
Date: 19 Jan 2007 22:32:19 -0500
Local: Mon, Jan 19 2007 9:32 pm
Subject: Re: Tascam MS-16 diodes found, still need gas relays
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Chris Lynch <ch...@choochoolarouge.com> wrote:

"The diodes, part number 5224544601, is available at $.55 cents

each.

The relays, p/n 5290010400, is available at $13.40 each. Please

add $4

for postage/freight per order for UPS ground service within
CONTINENTAL USA plus local and state sales taxes where

applicable.

Prices quoted are only for SHIPMENT WITHIN THE U.S. or its
territories."

Don't use the original replacement relays! They will just go bad

again...
I think there is an Omron in the Digi-Key catalogue with gold

contacts and
an identical pinout.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."



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JP Gerard View profile
So, I have 20V 5W Zeners in there and all is well. Works like it

should... but I need a good sessions with a bunch of punch ins to

really put it to the test. I know, 5W is overkill but that's all

I could get on short notice. So there, I think I replaced most

things now except resistors, coils, (most) ICs, transistors and

FETs. An IC upgrade is of course a possibility. Then no more

tweaking. Or perhaps I'll change the gain structure, I think

there's too much signal loss in the PB amps. Hmmm... JP
More options Jan 20 2007, 10:06 am

Newsgroups: rec.audio.pro
From: "JP Gerard" <jpgerard@skynet>
Date: Tue, 20 Jan 2007 17:08:31 +0100
Local: Tues, Jan 20 2007 10:08 am
Subject: Re: Tascam MS-16 diodes found, still need gas relays
Reply to author | Forward | Print | Individual message | Show

original | Report this message | Find messages by this author
So, I have 20V 5W Zeners in there and all is well.
Works like it should... but I need a good sessions with a bunch

of punch ins
to really put it to the test.
I know, 5W is overkill but that's all I could get on short

notice.
So there, I think I replaced most things now except resistors,

coils, (most)
ICs, transistors and FETs.
An IC upgrade is of course a possibility. Then no more tweaking.
Or perhaps I'll change the gain structure, I think there's too

much signal
loss in the PB amps.
Hmmm...

JP




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Chris Lynch View profile
More options Feb 18 2007, 2:10 pm

Newsgroups: rec.audio.pro
From: ch...@choochoolarouge.com (Chris Lynch)
Date: 18 Feb 2007 12:10:05 -0800
Local: Wed, Feb 18 2007 2:10 pm
Subject: Re: Tascam MS-16 diodes found, still need gas relays
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I'm afraid I don't know how to spec out a new relay. I've been

to
digikey, but there are thousands of Omron relays and I don't know
where to start! Do you have the digikey part number? Well, as

lame
as I am with electronics, I seem to have successfully fixed the

diode
problem, so thanks for everyone's help! Score one for the slow

guy!

-Chris

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