Re: Odd jumpers on a XT 2190 drive.

[Chuck Guzis via cctalk]

On 2/5/22 17:13, Jerry Wright via cctalk wrote:
> I'm going through  a few of my ESDI  and MFM hard drives  and ran across 2 
> Maxtor  XT 2190 drives with  all of the Drive Id's (1-4) tie together with 1 
> long 
> jumper and the drives have the write protect jumper is installed.  Not sure 
> what theywould have been used for ??? Both are the same.
> 
> Jerry

Seems to me that this would be a read-only drive accessible on any unit.
 Why?  Maybe holding diagnostic software?

--Chuck

Re: More switchmode power supply grief - Cisco IGS router

[Maciej W. Rozycki via cctalk]

On Sat, 5 Feb 2022, Peter Coghlan via cctalk wrote:

> >  This PSU seems to have been used across various Cisco devices and I had 
> > one fail several years ago in a WS-C1202 Ethernet/FDDI switch, also having 
> > suffered from leaking caps.  Back then RS still had it in stock at a hefty 
> > price of £489.60: , so I 
> > chose to recap the failed one and thanfully it has continued working ever 
> > since.  You may try to enquire with the manufacturer.
> > 
> >  Good luck with bringing yours back to life!
> >
> 
> Thanks Maciej.  I'll be surprised if the manufacturer has records of
> what they used for the chopper in power supplies 30 years ago - who
> knows if their design has changed between then and now.  I'll be even
> more suprised if they will talk to me about it but I guess it's worth
> a try.

 I've checked their web site and they continue to offer a MAP80-4000G, 
which I suppose is just a minor update from the original, and is visually 
the same, as it seems from the datasheet dated 2021.  So I'm fairly sure 
they have all the data.  Those discrete semiconductor components do not 
change much, I was able to order exact replacements for another faulty 
device from 1990s a few years ago.

 They may offer you a paid repair or replacement service or if you're kind 
enough and they are reasonable, they may identify the single part for you.

 NB Mouser has the MAP80-4000G in stock actually, so if all else fails and 
you are determined to get the IGS running, you can pick a brand new one: 
.

 Good luck!

  Maciej

Odd jumpers on a XT 2190 drive.

[Jerry Wright via cctalk]

I'm going through  a few of my ESDI  and MFM hard drives  and ran across 2 
Maxtor  XT 2190 drives with  all of the Drive Id's (1-4) tie together with 1 
long 
jumper and the drives have the write protect jumper is installed.  Not sure 
what theywould have been used for ??? Both are the same.

Jerry

Re: More switchmode power supply grief - Cisco IGS router

[Jonathan Chapman via cctalk]

Mean-Well is a maker of drop in power supplies. They sell a wide variety of 
sizes and output configurations. The supplies are (mostly) not expensive, 
though not as cheap as something you might dig up on e.g. AliExpress. They also 
won't burn your house down :)

The name is rather unfortunate.

All of the big part suppliers carry them. I have had better luck hitting the 
Mean-Well site and figuring out what I need, then searching the model # on e.g. 
Mouser. Often, it is cheaper to use two modules rather than finding one do-all 
with the current ratings you need, but the IGS should have fairly 
straightforward power requirements.

Sounds like we have the same kind of IGS!

Thanks,
Jonathan

--- Original Message ---

On Saturday, February 5th, 2022 at 17:17, Peter Coghlan via cctalk 
 wrote:

> What's a "Mean-Well module"? I somehow find myself imagining:
>
> "I put a new module in my router. It blew up. At least it meant well" :-)
>
> (My IGS has the rather heavy and over-engineered divider shelf with the
>
> main board underneath and the fan and power supply above.)
>
> Regards,
>
> Peter Coghlan
>
> Jonathan Chapman via cctalk wrote:
>
> > With that much carnage, I'd probably drop a Mean-Well module in there. I
> >
> > believe there would be enough room for one or two in the IGS I have
> >
> > (taller white box, divider "shelf" over the mainboard, I don't know if
> >
> > there was a lower profile model).
> >
> > Thanks,
> >
> > Jonathan
> >
> > --- Original Message ---
> >
> > On Saturday, February 5th, 2022 at 09:17, Phil Blundell via cctalk 
> > cctalk@classiccmp.org wrote:
> >
> > > On Thu, Feb 03, 2022 at 06:06:10PM +, Peter Coghlan via cctalk wrote:
> > >
> > > > Today I finally managed to check it out. The ceramic F4A mains input 
> > > > fuse
> > > >
> > > > beside the power switch on the back panel had blown. When I opened it 
> > > > up,
> > > >
> > > > I found a POWER-ONE MAP80-4000 power supply. The main chopper transistor
> > > >
> > > > labelled Q1 on the PCB is almost a dead short. It is a large plastic
> > > >
> > > > packaged FET mounted on a piece of aluminium which is in turn screwed to
> > > >
> > > > the case for heatsinking. Unfortunately, there are no markings on it so
> > > >
> > > > I have no idea what to replace it with :-(
> > > >
> > > > As Q1 is shorted across all three terminals, whatever drives it may be
> > > >
> > > > damaged too :-(
> > >
> > > Does that PSU have a PWM controller IC, or is it built entirely from 
> > > discretes?
> > >
> > > If there is an IC driving the chopper transistor then you may be able to 
> > > get
> > >
> > > some clues about the likely characteristics of the transistor from the IC
> > >
> > > datasheet. Is it definitely a FET? Some, particularly older, designs used
> > >
> > > bipolar transistors there.
> > >
> > > As you say there is a fairly high likelihood that other components on the
> > >
> > > primary side will have blown up as well so you might be looking at a 
> > > fairly
> > >
> > > extensive repair. Are there any other obscure, unmarked devices or is this
> > >
> > > the only one?
> > >
> > > p.

Re: More switchmode power supply grief - Cisco IGS router

[Peter Coghlan via cctalk]

What's a "Mean-Well module"?  I somehow find myself imagining:

"I put a new module in my router.  It blew up.  At least it meant well"  :-)

(My IGS has the rather heavy and over-engineered divider shelf with the
main board underneath and the fan and power supply above.)

Regards,
Peter Coghlan

Jonathan Chapman via cctalk wrote:
>
> With that much carnage, I'd probably drop a Mean-Well module in there. I
> believe there would be enough room for one or two in the IGS I have
> (taller white box, divider "shelf" over the mainboard, I don't know if
> there was a lower profile model).
>
> Thanks,
> Jonathan
>
> --- Original Message ---
>
> On Saturday, February 5th, 2022 at 09:17, Phil Blundell via cctalk 
>  wrote:
> 
> > On Thu, Feb 03, 2022 at 06:06:10PM +, Peter Coghlan via cctalk wrote:
> >
> > > Today I finally managed to check it out. The ceramic F4A mains input fuse
> > >
> > > beside the power switch on the back panel had blown. When I opened it up,
> > >
> > > I found a POWER-ONE MAP80-4000 power supply. The main chopper transistor
> > >
> > > labelled Q1 on the PCB is almost a dead short. It is a large plastic
> > >
> > > packaged FET mounted on a piece of aluminium which is in turn screwed to
> > >
> > > the case for heatsinking. Unfortunately, there are no markings on it so
> > >
> > > I have no idea what to replace it with :-(
> > >
> > > As Q1 is shorted across all three terminals, whatever drives it may be
> > >
> > > damaged too :-(
> >
> > Does that PSU have a PWM controller IC, or is it built entirely from 
> > discretes?
> >
> > If there is an IC driving the chopper transistor then you may be able to get
> >
> > some clues about the likely characteristics of the transistor from the IC
> >
> > datasheet. Is it definitely a FET? Some, particularly older, designs used
> >
> > bipolar transistors there.
> >
> > As you say there is a fairly high likelihood that other components on the
> >
> > primary side will have blown up as well so you might be looking at a fairly
> >
> > extensive repair. Are there any other obscure, unmarked devices or is this
> >
> > the only one?
> >
> > p.
>

Re: More switchmode power supply grief - Cisco IGS router

[Peter Coghlan via cctalk]

Phil Blundell wrote:
>
> Does that PSU have a PWM controller IC, or is it built entirely from 
> discretes?
> If there is an IC driving the chopper transistor then you may be able to get
> some clues about the likely characteristics of the transistor from the IC
> datasheet.
>

It's all discretes.  There are only about five or six TO-92 thingies in there
which are likely to be small signal transistors plus a few TO-220 style items
mounted on the heatsink that could be drivers and/or output rectifiers.  Come
to think of it, I suppose a FET is unlikely to need a driver on a heatsink?

>
> Is it definitely a FET?  Some, particularly older, designs used
> bipolar transistors there.
>

Even though there are no markings visible on the transistor, it's marked
S,D,G on the PCB!

If it was a bipolar, I'd probably chance a BU208A from the TV spares box.
What could go wrong :-)

>
> As you say there is a fairly high likelihood that other components on the
> primary side will have blown up as well so you might be looking at a fairly
> extensive repair.  Are there any other obscure, unmarked devices or is this
> the only one?

I've been a bit reluctant to handle the thing much to examine it closely,
between dust from the fan, stray electrolyte and heatsink compound where the
internal heatsinking used to be screwed to the case, it's very messy :-(

Except for the two main reservoir capacitors which seem to be sound, the
other electrolytics all seem to be Nichicon units and they all seem to have
leaked :-( I think lots of components are going to need to be desoldered
from the board to clean it.  That's going to get smelly :-( At least access
is very straightforward compared to a H7821 and way better than a H7816 :-)
No live heatsinks in this thing!

The bridge rectifier doesn't seem to be shorted.  The other heatsinked
components and small signal components seem to have markings on them so
it might not be too difficult to find replacements for those where needed,
provided I don't manage to swipe the numbers off them when cleaning the
up the leaked electrolyte...

Oh, there's a couple of RIFA capacitors with cracked cases in there too
but they're not input filters so no magic smoke escaped yet...

Regards,
Peter Coghlan.

>
> p.
>

Re: More switchmode power supply grief - Cisco IGS router

[Jonathan Chapman via cctalk]

With that much carnage, I'd probably drop a Mean-Well module in there. I 
believe there would be enough room for one or two in the IGS I have (taller 
white box, divider "shelf" over the mainboard, I don't know if there was a 
lower profile model).

Thanks,
Jonathan

--- Original Message ---

On Saturday, February 5th, 2022 at 09:17, Phil Blundell via cctalk 
 wrote:

> On Thu, Feb 03, 2022 at 06:06:10PM +, Peter Coghlan via cctalk wrote:
>
> > Today I finally managed to check it out. The ceramic F4A mains input fuse
> >
> > beside the power switch on the back panel had blown. When I opened it up,
> >
> > I found a POWER-ONE MAP80-4000 power supply. The main chopper transistor
> >
> > labelled Q1 on the PCB is almost a dead short. It is a large plastic
> >
> > packaged FET mounted on a piece of aluminium which is in turn screwed to
> >
> > the case for heatsinking. Unfortunately, there are no markings on it so
> >
> > I have no idea what to replace it with :-(
> >
> > As Q1 is shorted across all three terminals, whatever drives it may be
> >
> > damaged too :-(
>
> Does that PSU have a PWM controller IC, or is it built entirely from 
> discretes?
>
> If there is an IC driving the chopper transistor then you may be able to get
>
> some clues about the likely characteristics of the transistor from the IC
>
> datasheet. Is it definitely a FET? Some, particularly older, designs used
>
> bipolar transistors there.
>
> As you say there is a fairly high likelihood that other components on the
>
> primary side will have blown up as well so you might be looking at a fairly
>
> extensive repair. Are there any other obscure, unmarked devices or is this
>
> the only one?
>
> p.

Re: More switchmode power supply grief - Cisco IGS router

[Phil Blundell via cctalk]

On Thu, Feb 03, 2022 at 06:06:10PM +, Peter Coghlan via cctalk wrote:
> Today I finally managed to check it out.  The ceramic F4A mains input fuse
> beside the power switch on the back panel had blown.  When I opened it up,
> I found a POWER-ONE MAP80-4000 power supply.  The main chopper transistor
> labelled Q1 on the PCB is almost a dead short.  It is a large plastic
> packaged FET mounted on a piece of aluminium which is in turn screwed to
> the case for heatsinking.  Unfortunately, there are no markings on it so
> I have no idea what to replace it with :-(
> 
> As Q1 is shorted across all three terminals, whatever drives it may be
> damaged too :-(

Does that PSU have a PWM controller IC, or is it built entirely from discretes?
If there is an IC driving the chopper transistor then you may be able to get
some clues about the likely characteristics of the transistor from the IC
datasheet.  Is it definitely a FET?  Some, particularly older, designs used
bipolar transistors there.

As you say there is a fairly high likelihood that other components on the
primary side will have blown up as well so you might be looking at a fairly
extensive repair.  Are there any other obscure, unmarked devices or is this
the only one?

p.

Re: More switchmode power supply grief - Cisco IGS router

[Peter Coghlan via cctalk]

"Maciej W. Rozycki" wrote:
> On Thu, 3 Feb 2022, Peter Coghlan via cctalk wrote:
>
>> Today I finally managed to check it out.  The ceramic F4A mains input fuse
>> beside the power switch on the back panel had blown.  When I opened it up,
>> I found a POWER-ONE MAP80-4000 power supply.  The main chopper transistor
>> labelled Q1 on the PCB is almost a dead short.  It is a large plastic
>> packaged FET mounted on a piece of aluminium which is in turn screwed to
>> the case for heatsinking.  Unfortunately, there are no markings on it so
>> I have no idea what to replace it with :-(
>> 
>> As Q1 is shorted across all three terminals, whatever drives it may be
>> damaged too :-(
>> 
>> After finding screw heads hidden under the label, I managed to extract
>> the PCB from the case and found some corrosion underneath, possibly from
>> leaking electrolytic capacitors :-(
>
>  This PSU seems to have been used across various Cisco devices and I had 
> one fail several years ago in a WS-C1202 Ethernet/FDDI switch, also having 
> suffered from leaking caps.  Back then RS still had it in stock at a hefty 
> price of £489.60: , so I 
> chose to recap the failed one and thanfully it has continued working ever 
> since.  You may try to enquire with the manufacturer.
> 
>  Good luck with bringing yours back to life!
>

Thanks Maciej.  I'll be surprised if the manufacturer has records of
what they used for the chopper in power supplies 30 years ago - who
knows if their design has changed between then and now.  I'll be even
more suprised if they will talk to me about it but I guess it's worth
a try.

Regards,
Peter.

> 
>  FWIW,
> 
>   Maciej