Bob Roberts is mistaken
ra...@randyfromm.com
Once again, dear friends, I find that I must defend myself from the rantings
of the misinformed. I am referring to the following question from TNS30 and
the response from Bob Roberts. Since I really haven't a clue as to how the
"thread" thingie works with usenet, I have copied the messages below:
-------------------------------------------------------------
Subject: Re: Tech: Switching PS repair
From: Bob Roberts <bob...@bellsouth.net>
Date: 1998/02/26
Message-ID: <34F4E6...@bellsouth.net>
Newsgroups: rec.games.video.arcade.collecting
TNS30 wrote:
>
> I have a couple of used switching PS, both test high on DC volts and one has
> noise. I have read Randy Fromm's article but am a amateur at electronics
and
> am not sure what to look for. I checked for bad solder joints, fried
resitors
> and bulging caps but can't see anything visually. Anyone have any ideas
what I
> should check? Thanks everyone!
>
> Thanks,
>
> tn...@aol.com
*******************************
I think Randy is nuts on this one. Let me rephrase, when Randy
wrote those articles in the 80's when switchers were $75 & up
apiece they were worth fooling with. As cheap as they are today
on the market, I say chuck them for the potential damage they could
cause your board and buy a new one. I did them for years, till
I figured out it was costing on average $25 to repair a $25
power supply. All my parts were bought by the hundreds of each
item with manufacturers discounts, so what's it cost someone
to buy the parts individually.
Kind of reminds me of "The New Yankee Workshop" on PBS tv.
Everything is so easy to make, but look at the $100,000 shop
that he has to work with.
--
Big Bear...bob147@bellsouth.net...Thanks...Bob Roberts
------------------------------------------------------------
Bob, you are SO WRONG about this. First of all, the article on switching
regulator power supply repair was published in November of 1994, not in the
80's as you suggest. Prices for power supplies were about the same then as
they are now.
If it cost you $25.00 in parts, you're buying them from the wrong source or
replacing WAY too many components. We fix hundreds of power supplies during
the hands-on power supply lab that is a part of the Arcade School I teach.
Students bring in boxes of bad power supplies and I bring the replacement
components. I trade them good parts for bad. At the end, we tally-up the total
cost of the components we used and divide by the number of power supplies we
repaired. The average cost to repair a power supply is $1.60. This figure is
remarkably constant from class to class. The average time required to repair a
power supply is about an hour for first-timers and half that once you've done
a dozen or so. Well worth the effort to repair them, not to mention the fun
and personal satisfaction of doing so.
Your comment about the $100,000.00 shop is WAY off base and as wrong as it can
possibly be. Those who know me, know that I am a strong proponent of field
service with as little equipment as possible. I do almost all of my repair
with my Fluke model 11 digital multimeter. It costs a whopping $79.95 (plus
tax.)
Bob, please refrain from making these uninformed comments. Just for the sake
of being thorough, I looked at some of your hundreds of RGVAC posts. You
present yourself as an authority and while I do not dispute that you may be a
decent (maybe even damned good)game tech, you seem to have overlooked your
responsibility to be accurate in what you post. Your comments about me are
especially bothersome.
Thanks to all in the RGVAC newsgroup for reading this. As usual, if I can help
any of you, do not hestate to contact me.
See you at the Arcade School!
RF
randyfromm.com
1944 Falmouth Dr.
El Cajon, CA 92020-2827
United States of America
tel.+619.593.6131
fax.+619.593.6132
ra...@randyfromm.com
P.S. For more technical fun, you might consider attending the ASI show and the
Technical Olympics. See my website for details
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/ Now offering spam-free web-based newsreading
ra...@randyfromm.com
Bob Roberts
ra...@randyfromm.com wrote:
>
> Once again, dear friends, I find that I must defend myself from the rantings
> of the misinformed. I am referring to the following question from TNS30 and
> the response from Bob Roberts. Since I really haven't a clue as to how the
> "thread" thingie works with usenet, I have copied the messages below:
Sorry that my rantings are hurting your business, Randy.
I did not mean to attack you and I am certainly not misinformed.
> I think Randy is nuts on this one!
Well.....this may be a little offensive, but it is after all an
exclaimation!
> Let me rephrase, when Randy
> wrote those articles in the 80's when switchers were $75 & up
> apiece they were worth fooling with.
> As cheap as they are today
> on the market, I say chuck them for the potential damage they could
> cause your board and buy a new one. I did them for years, till
> I figured out it was costing on average $25 to repair a $25
> power supply. All my parts were bought by the hundreds of each
> item with manufacturers discounts, so what's it cost someone
> to buy the parts individually.
Hello, I'd like to order 2 3039 transistors please. Yeah right!
> Kind of reminds me of "The New Yankee Workshop" on PBS tv.
> Everything is so easy to make, but look at the $100,000 shop
> that he has to work with.
> --
> Big Bear...bob147@bellsouth.net...Thanks...Bob Roberts
> ------------------------------------------------------------
>
> Bob, you are SO WRONG about this. First of all, the article on switching
> regulator power supply repair was published in November of 1994, not in the
> 80's as you suggest.
Geez...Randy...Those 88/89 articles I read, must have been written by
someone
before you and using your name, at that. You must must be catching up
with me
in age, I guess. Would you like me to provide you with your own articles
as
written in 1988/89 for Playmeter Magazine?
> Prices for power supplies were about the same then as
> they are now.
Since you forgot what you wrote before, I'll let you slide to the year
1994.
1994 ...lot prices on average $34 retail $70 at distributors.
1998....lot prices on average $18 retail $75 at distributors.......
Wow!!!!!!!!!Have I been been unpricing!!!!!!!! I just picked 4
distributors
at random, and cannot dispute you on retail pricing end, but I don't
think
that you'll find anyone here paying that for them. Let me get my plug
in...
Peter Chou power supplies/$25 shipped to your door/USA and you don't
have
to buy 50...1 is probably all you need.
> If it cost you $25.00 in parts, you're buying them from the wrong source or
> replacing WAY too many components.
Geez......Randy... I guess you do not charge people in any way for your
time.
All this training /tapes /books they are free, right?
I put too many parts in?....I guess you don't have ops that that hook
the 110
AC to the wrong terminals.
I never said it cost me $25 for components. Unlike you, I cannot afford
to
give all my time away. My last hourly rate increase was in July of 1994
to
$30 per hour with a minimum $10 charge. Again, at random and using your
home
state, as well, I got rates from $45 to $90 per hour with $20 minimums
and
of all things some had storage charges, if you did not pick up
immediately
upon repair you pay daily storage charge. What's up there?
Again, since you say you did not say it, I won't quote you, but someone
in articles suggested taking all those cheap capacitors out and
replacing
"all those way too many parts" with more expensive ESR capacitors.
Wrong sources? You suggested them...oh I forgot you did not write those
articles.
> We fix hundreds of power supplies during
> the hands-on power supply lab that is a part of the Arcade School I teach.
> Students bring in boxes of bad power supplies and I bring the replacement
> components. I trade them good parts for bad. At the end, we tally-up the total
> cost of the components we used and divide by the number of power supplies we
> repaired. The average cost to repair a power supply is $1.60. This figure is
> remarkably constant from class to class. The average time required to repair a
> power supply is about an hour for first-timers and half that once you've done
> a dozen or so. Well worth the effort to repair them, not to mention the fun
> and personal satisfaction of doing so.
If y'all don't see the seven flaws in this statement, I certainly cannot
afford
to point them all out to you, but I will ask you the people, who
comprise the
group...RGVAC...this question, would you rather be admiring your
collection or
playing them as opposed to getting dozens of old power supplies to play
with?
> Your comment about the $100,000.00 shop is WAY off base and as wrong as it can
> possibly be. Those who know me, know that I am a strong proponent of field
> service with as little equipment as possible. I do almost all of my repair
> with my Fluke model 11 digital multimeter. It costs a whopping $79.95 (plus
> tax.)
Geeeez..Randy......I must ask, I feel it's my duty after that statement.
Do you think the world revolves around you? I did not direct that at
you,
but more as an observation of a scenario.
You are paying way too much for your meters. I get mine at the shack for
$39.95 (plus tax). Also, the period goes on the outside of the
parenthesis.
> Bob, please refrain from making these uninformed comments.
EXCUSE ME!!! I have been a lisenced tech in the state of Louisianna
since
1979 and before that in New Hampshire begining in 1966. I have dedicated
my life to coin op repair and was working on Bally Sea Islands while you
were in grammar school at best.
> Just for the sake
> of being thorough, I looked at some of your hundreds of RGVAC posts. You
> present yourself as an authority and while I do not dispute that you may be a
> decent (maybe even damned good)game tech, you seem to have overlooked your
> responsibility to be accurate in what you post. Your comments about me are
> especially bothersome.
I'm sorry that you are bothered by something so trivial, but accurate,
I think you just presented a VERY good case for who is the accurate one.
If I didn't have to worry about copyrights...I'd retape your first tape
on power supplies and give it away free!
Sorry, but I must go back to the real-world repairing now, to support
my family. I apologize to the group...but I didn't take the gloves off
first! Now I must go check my blood pressure before returning to work.
Sept 2000 seems along way away today.
> Thanks to all in the RGVAC newsgroup for reading this. As usual, if I can help
> any of you, do not hestate to contact me.
>
********
Ditto ...and who was it that said a good defense is a strong offense?
Randy, it takes a real man to do what you did in your opening paragraph.
****paste***I really haven't a clue***paste***
There, now you made me take my gloves off:)...and any time you wish to
take
back your remarks about this ranting/misinformed person, feel free to do
so.
I can be friendly, too! Check...your move!
--
Big Bear...bob147@bellsouth.net...Thanks...Bob Roberts
Lance K.
So does anyone think Randy is going to open his mouth again, or do you
think he has learned to shut-up?
Jess Askey
TNS30 wrote:
>
> All this and Tns30 still can't get a good reading on -5v, although +5v and +12
> check out fine. :)
> Sorry Guys! I didn't mean to instigate a war here - I just wanted to know if I
> could be cheap and fix my P.S.
> If anyone does have any ideas tho' please let me know. I already replaced all
> the caps and it still don't workie.
Okay, I'll throw in my .02 here.
If you do have -5V then that means that the primary side oscillator is
running and transformer
okay (primary at least). Do you have an o-scope? What brand is the Power
supply? Or if there is no
noticable brand name, what color is it?
Strange that both the +5 AND +12 are down, they are usually (and most
likely in this case as well)
on seperate windings of the transformer. Are you getting these readings
with the Game PCB, etc
connected to the PS? Try pulling off all the connections to the outputs
(+5V, -5V, +12V) keep note where
they came off. Now see what you have, report back and we will get this
sucker fixed.
It may not be worth repairing in the end... timewise, but at least you
will learn how a switching power supply
works. :-)
jess
--
Jess M. Askey *** Coming Soon - The Game Archive ***
Game Spot/Audio Analyst * Pinball, Video, Parts, Collecting *
509 S. 2nd Street Unit B * http://www.gamearchive.com *
Laramie WY 82070 **************************************
Crazy Frazee's LLC
TNS30 wrote:
>
> All this and Tns30 still can't get a good reading on -5v, although +5v and +12
> check out fine. :)
> Sorry Guys! I didn't mean to instigate a war here - I just wanted to know if I
> could be cheap and fix my P.S.
> If anyone does have any ideas tho' please let me know. I already replaced all
> the caps and it still don't workie.
>
Are you sure going to all this trouble is worth fixing it when $29
will get you a brand new PS that will last longer?
When a PS goes out in my shop- I throw it straight into the dumpster
and pop in a new one in 5 minutes- end of story- game fixed.
PauL F.
CRAZY FRAZEE'S LLC Operator/retailer/distributor of
7748 TROOST AVE. new/used amusement devices,old
KANSAS CITY ,MO 64131 parts, and related equipment.
(816)361-8898/374-5848 Quarterly Amusement Auctions held.
TNS30
All this and Tns30 still can't get a good reading on -5v, although +5v and +12
check out fine. :)
Sorry Guys! I didn't mean to instigate a war here - I just wanted to know if I
could be cheap and fix my P.S.
If anyone does have any ideas tho' please let me know. I already replaced all
the caps and it still don't workie.
Al Kossow
From article <19980317020...@ladder01.news.aol.com>, by tn...@aol.com (TNS30):
> All this and Tns30 still can't get a good reading on -5v, although +5v and +12
> check out fine. :)
1) if you are doing the testing on the bench make sure you have a load on
the 5V supply (an amp or so..)
3) if you have a scope handy, take a look at the output of the step down
transformer for the -5v Is the winding open?
2) check any of the other components in the -5v supply (rectifier diode?)
4) does the -5v supply use a 3 terminal regulator off of some other supply?
(sometimes PC supplies would just regulate -5 down from the -12 supply)
Paul Swan
Dear All,
I look at this from a slightly different point of view. I could spend half an
hour or so tracing a switched mode PS fault, identify the component, find a
supplier, order a replacement, wait for it to arrive, fit it and then test it
again. The component may cost only a couple of pounds but since a new PSU's
can be got for 10 to 20 pounds, it's not worth my time or the risk of killing
myself.
Second hand JAMMA or Electrocoin cabs are so cheap (25 pounds direct scrap
value) that so far I haven't even bothered with monitors, either.
Regards,
Paul.
--
**************************************************
* V I D E O A R C A D E G A M E W W W *
**************************************************
* http://easyweb.easynet.co.uk/~swan/arcade.htm *
**************************************************
The Retrodaddy
On Mon, 16 Mar 1998 23:08:21 -0600, Crazy Frazee's LLC
<crzy...@swbell.net> wrote:
>> the caps and it still don't workie.
>will get you a brand new PS that will last longer?
>When a PS goes out in my shop- I throw it straight into the dumpster
>and pop in a new one in 5 minutes- end of story- game fixed.
and check for a blown fuse. Half the time, that fixes them, the other
half are in the landfill.
My Web Page for arcade machine sales
http://arcade.hypermart.net/
Emulation Pages
http://www.geocities.com/SiliconValley/Bay/7268/
My ICQ Pager Number is 169923
spamt...@usa.net
bob...@bellsouth.net wrote:
>
> ra...@randyfromm.com wrote:
> >
<snip>
> > If it cost you $25.00 in parts, you're buying them from the wrong source
or
> > replacing WAY too many components.
>
> Geez......Randy... I guess you do not charge people in any way for your
> time.
> I never said it cost me $25 for components. Unlike you, I cannot afford
> to
> give all my time away.
Well, guys, I think there is a little confusion about the target audience
here. I don't think the original poster, a collector who was aking if it
is feasible to fix his own power supply, was charging anybody for his
time.
I, for one, enjoy working on electronics and just recently spent an hour
or two (this was my first power supply repair) trying to fix a power supply
that I had already replaced. If I was charging somebody $50/hr to fix it,
it wouldn't be worth it, but for me, when I had nothing better to do anyway,
it cost me nothing to troubleshoot it. Now if I can find a couple of C3040
transistors cheap and local I'll be set. (I haven't really looked for them
yet.)
Even if you are charging $30/hr, if you can fix most in 30 min for $1.60
in parts, that's only $16.60. I'd say it's borderline as to whether it's
worth it or not in that case, assuming you can get new switchers for around
$20. If you're time is worth much more than $30/hr then using that time
to fix power supplies is not cost-effective. If you put 110VAC on the
wrong terminals, you'd probably just throw it out, so that shouldn't affect
your average.
<snip>
> > We fix hundreds of power supplies during
> > the hands-on power supply lab that is a part of the Arcade School I teach.
> > Students bring in boxes of bad power supplies and I bring the replacement
> > components. I trade them good parts for bad. At the end, we tally-up the
total
> > cost of the components we used and divide by the number of power supplies
we
> > repaired. The average cost to repair a power supply is $1.60. This figure
is
> > remarkably constant from class to class. The average time required to
repair a
> > power supply is about an hour for first-timers and half that once you've
done
> > a dozen or so. Well worth the effort to repair them, not to mention the
fun
> > and personal satisfaction of doing so.
>
> If y'all don't see the seven flaws in this statement, I certainly cannot
> afford
> to point them all out to you, but I will ask you the people, who
> comprise the
> group...RGVAC...this question, would you rather be admiring your
> collection or
> playing them as opposed to getting dozens of old power supplies to play
> with?
Let's ask the collectors this question too: How much do you charge for your
time while you're working on your own games? Is an hour of your time
(and a couple bucks in parts) worth a $20-$25 power supply?
Oh, that's two questions... oh well.
Just for the record, my answers were $0/hr and yes.
> > Your comment about the $100,000.00 shop is WAY off base and as wrong as it
can
> > possibly be. Those who know me, know that I am a strong proponent of field
> > service with as little equipment as possible. I do almost all of my repair
> > with my Fluke model 11 digital multimeter. It costs a whopping $79.95
(plus
> > tax.)
>
> Geeeez..Randy......I must ask, I feel it's my duty after that statement.
> Do you think the world revolves around you? I did not direct that at
> you,
> but more as an observation of a scenario.
>
> You are paying way too much for your meters. I get mine at the shack for
> $39.95 (plus tax). Also, the period goes on the outside of the
> parenthesis.
Geez, Bob... if period placement bothers you that much, no wonder
your blood pressure is up.
<snip>
> Sorry, but I must go back to the real-world repairing now, to support
> my family. I apologize to the group...but I didn't take the gloves off
> first! Now I must go check my blood pressure before returning to work.
> Sept 2000 seems along way away today.
>
In conclusion, you're both right, but from different perspectives. As
a collector, I would agree with Randy that I can fix my own power supply
cheaper than I can buy a new one. But, to paraphrase Bob, if I was charging
someone else for my time to fix the same power supply, I could probably
sell them a new one at least as cheap as I could fix it.
Now everybody chill out and play some Tempest.... :)
andy r
If I had 100 broken supplies, and I could easily go from 1 to the next
fixing them. That might be an option. When you do it for a living, fixing
them is ALWAYS an option. However, I don't. It doesn't matter, but
generally I dont even have enough time to scratch my butt, let alone look
at a $20 dollar component, so I put it on the side, buy a new one and not
worry about it.
Its not that 'my time' is worth ALOT. Its that all I need to do is make a
mistake (hey it happens!), screw something up, and my game or the guys that
I am fixing, could be toast.. I can't afford that.
Andy
Peter Fyfe
>From article <19980317020...@ladder01.news.aol.com>, by tn...@aol.com (TNS30):
>> All this and Tns30 still can't get a good reading on -5v, although +5v and +12
>> check out fine. :)
Most switchers derive the -5V output via a 7905 three terminal
regulator. Open up the PSU (with the power disconnected) and trace
the -5V back to see if it is derived from the afore mentioned device.
If so switch the unit on (you'll need a small load on the +5V output,
an amp or so should be sufficient), keep away from the mains input.
The center pin of the device is ground (i think), one of the other
pins should have a high negative voltage (-12V or so) and the other
pin should be your -5V output. If you have the negative input but no
output then change the 7905. Otherwise, you'd be best to swap power
supplies.
Peter