Digest for sci.electronics.repair@googlegroups.com - 25 updates in 7 topics

Tim R <timothy42b@aol.com>: Dec 29 03:25PM -0800

I've often run a stereo miniplug out to two RCA plugs into a stereo amp for an iPod, boombox, laptop, without problems. My main system runs that way, with a miniplug into the headphone out on a Win10 machine, into a decent stereo amp and floor speakers. I have another system running the USB out into an M-Audio interface, then RCA cables into that stereo. Both work great.
 
I just tried putting speakers on the rec room laptop where the wifi reaches.
 
Only one speaker works. So here was my troubleshooting order:
 
swapped the speakers, left for right. Nope, they both work, but only on the one side.
 
Swapped the stereo amp for a different one. Same results.
 
Okay, maybe it's the laptop port. Put in earbuds from my phone, both sides work.
 
Aha! It's the cable. Got two more miniplug to RCA cables, still only one side audio. Not the cable, unless I have 3 bad ones.
 
Then and only then went to google: common problem, adjust the speaker volume and balance settings and it goes away. Nope, still doesn't work.
 
Still could be the laptop jack. Carry it upstairs to the system known to work. Works fine up there. Great, it's fixed, carry it back down and ............... nope, won't work on the amp down there.
 
What am I missing? I've tried speakers, amps, cables, and software, I don't know where to go next. Oh, maybe should mention, this is an older laptop. It came with System 7 but when the harddrive crashed we couldn't get another 7 without paying the cost of another laptop so we put on XP.
jurb6006@gmail.com: Dec 29 04:32PM -0800

You can almost always download a replacement disk fro the manufacturer, or Microsoft. You will get an ISO file, this is needed top make the disk bootable. It takes a special burning program to actually burn the CD. I use Power to go. Freeware and n0t invasive.
 
I say this because you probably have a compatabiity issue. Windows XP has been out for a log time, there was no bluetooth. There was wireless but not bluetooth.
 
It's nice how they get you to pay to get something that is for free.
Tim R <timothy42b@aol.com>: Dec 29 04:42PM -0800

> You can almost always download a replacement disk fro the manufacturer, or Microsoft. You will get an ISO file, this is needed top make the disk bootable. It takes a special burning program to actually burn the CD. I use Power to go. Freeware and n0t invasive.
 
> I say this because you probably have a compatabiity issue. Windows XP has been out for a log time, there was no bluetooth. There was wireless but not bluetooth.
 
> It's nice how they get you to pay to get something that is for free.
 
Yes. I called the manufacturer. They asked for the product code from the box, which I'd saved. I read it to them and they said sorry, that was installed by the retailer, you'll have to pay full price for a new system.
mike <ham789@netzero.net>: Dec 29 06:43PM -0800

On 12/29/2017 3:25 PM, Tim R wrote:
 
> Then and only then went to google: common problem, adjust the speaker volume and balance settings and it goes away. Nope, still doesn't work.
 
> Still could be the laptop jack. Carry it upstairs to the system known to work. Works fine up there. Great, it's fixed, carry it back down and ............... nope, won't work on the amp down there.
 
> What am I missing? I've tried speakers, amps, cables, and software, I don't know where to go next. Oh, maybe should mention, this is an older laptop. It came with System 7 but when the harddrive crashed we couldn't get another 7 without paying the cost of another laptop so we put on XP.
 
WE have no idea the laptop details or the OS version.
Some random thoughts:
If you have a windows 7 COA on the laptop, you can download the bits
to make it work. I'm too lazy to look it up if you don't need it.
 
Did you update XP to SP3? They made a lot of changes over the years.
 
Did you try to find a better sound card driver for the laptop?
 
Sometimes the audio jack detects what's on there and sets itself up
accordingly. Try a 32 ohm resistor to ground on each audio line to see
if that helps.
Probably can be a lot bigger resistors, I just have no idea what the
threshold might be.
Ralph Mowery <rmowery28146@earthlink.net>: Dec 29 11:03PM -0500

In article <5f76f859-64dd-477a-9048-b6e3d8acee3e@googlegroups.com>,
jurb6006@gmail.com says...
 
> You can almost always download a replacement disk fro the manufacturer, or Microsoft. You will get an ISO file, this is needed top make the disk bootable. It takes a special burning program to actually burn the CD. I use Power to go. Freeware and n0t invasive.
 
> I say this because you probably have a compatabiity issue. Windows XP has been out for a log time, there was no bluetooth. There was wireless but not bluetooth.
 
> It's nice how they get you to pay to get something that is for free.
 
I am not sure how old my netbook is,but it has win XP on it and has
Bluetooth.
"Paul Hovnanian P.E." <paul@hovnanian.com>: Dec 29 08:24PM -0800

Tim R wrote:
 
[snip]
> don't know where to go next. Oh, maybe should mention, this is an older
> laptop. It came with System 7 but when the harddrive crashed we couldn't
> get another 7 without paying the cost of another laptop so we put on XP.
 
Old laptop may have a slightly recessed audio jack. So a standard mini plug
won't seat fully and make connection with left and right channel contacts in
the jack.
 
--
Paul Hovnanian mailto:Paul@Hovnanian.com
------------------------------------------------------------------
I bet the human brain is a kludge. -- Marvin Minsky
Tim R <timothy42b@aol.com>: Dec 30 08:04AM -0800

On Friday, December 29, 2017 at 9:43:43 PM UTC-5, mike wrote:
> to make it work. I'm too lazy to look it up if you don't need it.
 
> Did you update XP to SP3? They made a lot of changes over the years.
 
> Did you try to find a better sound card driver for the laptop?
 
Sorry, I didn't include any system details because I was looking hardware first.
 
Because hardware is less frustrating to fix, not because of inherent logic.
 
If it matters, it is an ASUS K501, running XP Professional 2002 with Service Pack 3. CPU is a Pentium dual core T4400@2.2 Ghz. 2.96 Gb RAM. All this from clicking on the system folder. It doesn't describe the sound card but says there is VIA HD Audio, and Legacy Audio Driver. I tried to update, it told me it couldn't find any better driver.
N_Cook <diverse@tcp.co.uk>: Dec 30 01:12PM

GFS and WRF both have the heavy winds passing between Brest and Nantes,
then continuing over northern France.
But WRF has the secondary low curving more and breaking out in the St
Malo, Channel Islands area of sea. Then over Cherbourg peninslar going
along the north coast of France.
But who would bet on that track instead of continuing out to mid
channel? 1987 in back of mind.
N_Cook <diverse@tcp.co.uk>: Dec 30 01:14PM

On 30/12/2017 13:12, N_Cook wrote:
> along the north coast of France.
> But who would bet on that track instead of continuing out to mid
> channel? 1987 in back of mind.
 
ignore ,should have gone to
uk.sci.weather
Fox's Mercantile <jdangus@att.net>: Dec 30 07:34AM -0600

On 12/30/17 7:14 AM, N_Cook wrote:
>> channel? 1987 in back of mind.
 
> ignore ,should have gone to
> uk.sci.weather
 
It's ok Nigel, it still makes more sense than the idiots arguing over
smoke machines for testing BMWs and Apple batteries.
 
Jeff
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Mike Coon <gravity@mjcoon.plus.com>: Dec 30 03:25PM

In article <p283f3$g8c$2@dont-email.me>, diverse@tcp.co.uk says...
> > channel? 1987 in back of mind.
 
> ignore ,should have gone to
> uk.sci.weather
 
Or Specsavers? ;-)
 
Mike.
oldschool@tubes.com: Dec 29 11:02PM -0600

I have one of these USB hubs with several USB connectors, which plugs
into a single USB port on a computer. It dont work. If I plug in a flash
drive directly to the computer, I can access that drive. But if I plug
it into the hub, the drive never shows up. I tried this on 3 computers.
 
I opened that hub, and there is a circuit board, with each output port
connected to a trace on the board which goes to a black dot on the
board. I dont know what that "dot" is, but I assume it's a chip of some
sort, and it looks like the dot itself was some sort of epoxy placed in
the board.
 
This was a gift, and it's going to get returned to the store, but I am
just wondering what kind of circuit this is?
 
Until looking at the innards, I thought that these hubs were just a
direct connection to the input (from computer) USB. But I see there is
more to it....
mike <ham789@netzero.net>: Dec 29 10:33PM -0800


> Until looking at the innards, I thought that these hubs were just a
> direct connection to the input (from computer) USB. But I see there is
> more to it....
 
Which version of which operating system?
How old is the computer?
What happens when you try it on a different computer?
What does device manager say?
What happens when you boot a linux live CD?
Make/model of the hub? Somebody may have one and actually have
a direct answer.
There were hubs that required you to install a driver,
but that was a LONG time ago.
But "oldschool tubes" suggests you might have really old stuff ;-)
rickman <gnuarm@gmail.com>: Dec 30 03:03AM -0500


> Until looking at the innards, I thought that these hubs were just a
> direct connection to the input (from computer) USB. But I see there is
> more to it....
 
USB is a point to point interface unlike some versions of Ethernet (using
coax) or an RS-485 multipoint interface. To connect more than one device to
a USB port requires a hub. The hub has a chip which receives packets sent
from the computer as well as packets received from any of the down stream
ports, buffers them and retransmits them on the appropriate other port.
That multiport interface chip is what is under the blob of epoxy on your
board. They use a chip directly with no package because it saves a few
pennies.
 
When you plug the hub into your computer it should show up as a hub. Under
windows you can go into the device manager and find it there. If the driver
did not install correctly it will show with a yellow error symbol next to it
and be listed as an unidentified device. If it doesn't show in the device
manager list at all while the flash drive works in the PC port, the hub is
defective. If it shows up but with the driver error, you may need to search
the Internet to find a driver.
 
--
 
Rick C
 
Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998
Rob <nomail@example.com>: Dec 30 11:04AM


> Until looking at the innards, I thought that these hubs were just a
> direct connection to the input (from computer) USB. But I see there is
> more to it....
 
There are hubs that come with a power supply so they can deliver more
power to the connected devices than can be supplied by a single port
at the computer, and there are hubs without powersupply.
 
It may be that yours has the powersupply misplaced and won't work
without it. Look for an extra connector on the case that is not a
USB input or output.
Jasen Betts <jasen@xnet.co.nz>: Dec 30 11:37AM

> the board.
 
> This was a gift, and it's going to get returned to the store, but I am
> just wondering what kind of circuit this is?
 
The blob conceals an silicon chip mounted on the board this type of
construction is called "Chip On Board" or "COB" the chip does the
signal routing, translation, and forwarding and needed to support
USB hubbing
 
> Until looking at the innards, I thought that these hubs were just a
> direct connection to the input (from computer) USB. But I see there is
> more to it....
 
Yeah, somehow they call it USB but electrically it's not what I would
consider to be a bus.
 
--
This email has not been checked by half-arsed antivirus software
"pfjw@aol.com" <pfjw@aol.com>: Dec 30 04:39AM -0800


> This was a gift, and it's going to get returned to the store, but I am
> just wondering what kind of circuit this is?
>>SNIP<<
 
The moment you opened the device, you lost the right to return it. Full stop.
 
Peter Wieck
Melrose Park, PA
bruce2bowser@gmail.com: Dec 30 02:12AM -0800

Mr. Man-wai Chang wrote:
 
> https://www.google.com.hk/search?q=computer+chassis+screw+thread+size
 
> And don't forget about Amazon:
 
> https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=screws+computer+chassis
 
Are you measuring in trade or metric? There's a conversion chart here:
 
-- http://elginfasteners.com/resources/metric-bolt-conversion-metric-to-standard-bolt-conversion/
Jeff Liebermann <jeffl@cruzio.com>: Dec 29 08:57AM -0800

On Fri, 29 Dec 2017 11:32:05 -0500, bitrex
>> an enzyme that regulates activity in your eyes.
 
>Interesting, never knew about that side effect. I'll report back my
>empirical findings after the upcoming New Year's weekend
 
At this point, I would normally scribble a variety of sexually
explicit observations and suggestions. However, this is a family
newsgroup and such things are unfortunately deemed unacceptable.
 
Technical details: I'm told that it's not a "blue shift" but rather a
"blue tint". Also, the color varies but is generally considered to be
cyan (between blue and green) and not blue.
 
Full disclosure: I've never noticed the blue tint effect, probably
because I was too busy and distracted at the time.
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Harry Newton <harryne_wton@AlliOSusersJustGiveUp.com>: Dec 30 10:07AM

On Fri, 29 Dec 2017 08:57:24 -0800, Jeff Liebermann wrote:
 
> Full disclosure: I've never noticed the blue tint effect, probably
> because I was too busy and distracted at the time.
 
And all this time I thought I was looking through the world with
rose-tinted glasses!
Sofa Slug <sofaslug@invalid.invalid>: Dec 29 10:21AM -0800

On 12/28/2017 9:58 AM, Michael A Terrell wrote:
>> converters (for an AM radio) out of my Volkswagen bus. Whoever stole
>> it left a dollar bill in it's place.
 
>    Did they ever come back for their change? ;-)
 
Ha Ha ...no, but later while in college, I had a 4 track car stereo that
I hated. it didn't sound very good and was always eating tapes - a real
POS. Instead of throwing it away, I took it out of the dash and left it
on the passenger seat in a box with all the tapes.
 
When I returned from class later that day, the box was gone.
Michael A Terrell <mike.terrell@earthlink.net>: Dec 29 08:18PM -0500

Sofa Slug wrote:
> a real POS. Instead of throwing it away, I took it out of the dash
> and left it on the passenger seat in a box with all the tapes.
 
> When I returned from class later that day, the box was gone.
 
 
That's almost as good as wrapping up a box of dog crap, and leaving
it out as a trap. :)
Fox's Mercantile <jdangus@att.net>: Dec 29 11:02AM -0600

On 12/29/17 10:39 AM, David Farber wrote:
> That being said, I think you were implying it's still better to use the
> metal tabbed package and use insulating hardware which will improve the
> thermal transfer. Is that correct?
 
Just a wild guess here...
But I suspect the epoxy coating may have less thermal resistance
than a mica washer with the bare metal tab.
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
"David Farber" <farberbear.unspam@aol.com>: Dec 29 10:40AM -0800

Fox's Mercantile wrote:
 
> Just a wild guess here...
> But I suspect the epoxy coating may have less thermal resistance
> than a mica washer with the bare metal tab.
 
I suspect the difference will have minimal effect on the operation of the
mixer. I'll opt for the epoxy coated device.
 
Thanks for your reply.
--
David Farber
Los Osos, CA
John-Del <ohger1s@gmail.com>: Dec 29 04:35PM -0800

On Friday, December 29, 2017 at 12:02:38 PM UTC-5, Fox's Mercantile wrote:
> Jeff-1.0
> WA6FWi
> http:foxsmercantile.com
 
 
 
Fullpack transistors generally have a much lower wattage rating than their metal backed counterparts for that very reason.
You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page.
To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

1 Response to Digest for sci.electronics.repair@googlegroups.com - 25 updates in 7 topics

March 20, 2020 at 12:11 AM

Thanks for this helpful information shared in this blog.

Post a Comment