Help with Lambda power supply
Sam Hall
supply. Suddenly and without any warning or "smoke" stopped working--0v DC
output. Anyone out there know of any service facility that repairs this
type of power supply?? Called Lambda and they didn't seem very interested
in repairing this old supply, especially since I was not an industrial user.
I don't have a schematic. Any ideas??
Thanks and 73, Sam--K8WVA--
Gary Coffman
Yeah, but you won't like them, Sam. About the only practical way to troubleshoot
these supplies is to individually test the components. The crazy protection circuits
won't let you do conventional troubleshooting. Some of the parts can only be
effectively tested by substitution, which means you need an inventory of parts
for this thing to repair it economically. We chunked ours in the dumpster and
replaced it with a diesel truck battery and float charger after going through that
for about the tenth time.
Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
<my ham call> e l l s o u t h . n e t
wrote:
>Yeah, but you won't like them, Sam. About the only practical way to troubleshoot
>these supplies is to individually test the components. The crazy protection circuits
Agreed. At work, we essentially consider a switching supply to be a
component - we're no more likely to try to repair one than we are to
try to fix a defective capacitor.
73 Doug
Doug Smith (ham call W9WI) - EM66 nr. Nashville, TN, USA
real email address is:
{my ham call} @ b e l l s o u t h . n e t (kill the spaces!)
Gary Coffman
>On Fri, 25 Sep 1998 20:11:58 GMT, ke...@bellsouth.net (Gary Coffman)
>wrote:
>>Yeah, but you won't like them, Sam. About the only practical way to troubleshoot
>>these supplies is to individually test the components. The crazy protection circuits
>
>Agreed. At work, we essentially consider a switching supply to be a
>component - we're no more likely to try to repair one than we are to
>try to fix a defective capacitor.
Well, all switchers aren't as bad as Lambdas. Some of them are
downright easy to troubleshoot and repair. Lambda is in a class
of its own when it comes to unrepairable switchers. The designer
of this particular supply must have gotten some bad acid the
day he designed it. The feedback paths are insane.
<my ham call> e l l s o u t h . n e t
wrote:
>Well, all switchers aren't as bad as Lambdas. Some of them are
>downright easy to troubleshoot and repair. Lambda is in a class
>of its own when it comes to unrepairable switchers. The designer
>of this particular supply must have gotten some bad acid the
>day he designed it. The feedback paths are insane.
The only one I've ever had much luck with was the ones in the old
Apple ][ computers.
I have succeeded in repairing a couple of other ones by replacing
every electrolytic capacitor, and every transistor and/or diode that
tested shorted. But for every one that succeeded, there were 4 or 5
that were lost causes.....
I do have a bunch of Lambda *linear* supplies at work that work great,
and have been in service for something like 25 years without a
failure...
73 Doug
Doug Smith (ham call W9WI) - EM66 nr. Nashville, TN, USA
real email address is:
{my ham call} @ b e l l s o u t h . n e t (kill the spaces!)
w_ni...@my-dejanews.com
sca0...@mail.wvnet.EDU (Sam Hall) wrote:
> Have a Lambda Model LGSEEA-15-OV-R, which is a 65 amp 15 volt switching
> supply. Suddenly and without any warning or "smoke" stopped working--0v DC
> output. Anyone out there know of any service facility that repairs this
> type of power supply?? Called Lambda and they didn't seem very interested
> in repairing this old supply, especially since I was not an industrial user.
> I don't have a schematic. Any ideas??
>
>
> I can help U with a schematic, I can also repair the supply the problem is I live and work in Europe so that isn't much help.Contact me via hotmail and I will try to make an attachment and mail u a schematic p.s. be aware that all components have LAMBDA specific identification i.e. I.C's = FBTXXXX
transistors are FBNL-XXXX diodes are FBL-XXXX and zeners are FBMZ-XXXX
these numbers have absolute no relation with JEDEC coding.
regards Bill N.
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum