I wasn't able to find any archived info regarding repair of this somewhat
sophisticated, high current PSU. This is the 180W version of this ADP series
of SMPSs.

The process of disassembly wasn't trivial.. Loctite has been used on
numerous internal screws during assembly, but heating them with an iron can
loosen the threadlocker well enough to remove the screws without stripping
out the
shallow #1 phillips recesses.

The top of the single-sided 4"x6.5" board looks straighforward enough that
it appears to be repairable, however, the bottom/foil side has a lot of
surface
mount circuitry (roughly half of the bottom side) which causes me to think
that repairing these supplies isn't simple.

The in-circuit ESR of the few (only 5) electrolytics appear to be good. Two
of them are rated 125C, the others are 105C.

The single 12V output is just 2 leads to the 6-contact plug at the end of a
shielded, 12 gage cord (pins 1, 2, 3 Gnd, and 4, 5, 6 positive).

The symptom is similar to the tick-tick failed startup of other SMPS, where
the output occurs in brief pulses at about 5 second intervals.
The load used is a #9004 halogen automotive hi/lo beam headlamp 45W 3.75A
and 65W 5.4A.

No load - the LED pulses on at about 5 second intervals, while a DMM display
wanders erratically between 3V and 11V.

Medium load - ~45W same pulses as above, and a brighter pulse after AC power
is
shut off.

High load - ~65W same as above.

Large load - ~110W No pulses during power on or after AC is shut off.

I haven't been doing service repairs for years, but I have an isolation
transformer (PR57) and safe troubleshooting habits, but the large number of
surface mount components on the board have me leaning toward an unlikely
repair, unless someone would be willing to offer some helpful advice.

Other observations:
As an aside comment, there is a surface mount IC where 2 of the pins have
been eliminated/omitted (not cut off), apparently to save money in
fabrication.. I've never seen this before.

The board manufacturer is Delta. For use with Information Technology
equipment.
ADP-180AB Made in China DCWP CM-2, CC: BB Rev 03.

Input: 100-240VAC 2500mA. The AC line fuse is 4A 250V.
Output: 12 VDC 15000mA.

The plastic case is unvented. The thin sheetmetal "shields" are secured to
the heatsinks with heatsink grease to increase the surface area of the
heatsinks.

--
Cheers,
WB
..............

"Wild_Bill" schreef in bericht
...
I wasn't able to find any archived info regarding repair of this somewhat
sophisticated, high current PSU. This is the 180W version of this ADP
series
of SMPSs.

The process of disassembly wasn't trivial.. Loctite has been used on
numerous internal screws during assembly, but heating them with an iron
can
loosen the threadlocker well enough to remove the screws without stripping
out the
shallow #1 phillips recesses.

The top of the single-sided 4"x6.5" board looks straighforward enough that
it appears to be repairable, however, the bottom/foil side has a lot of
surface
mount circuitry (roughly half of the bottom side) which causes me to think
that repairing these supplies isn't simple.

The in-circuit ESR of the few (only 5) electrolytics appear to be good.
Two
of them are rated 125C, the others are 105C.

The single 12V output is just 2 leads to the 6-contact plug at the end of
a
shielded, 12 gage cord (pins 1, 2, 3 Gnd, and 4, 5, 6 positive).

The symptom is similar to the tick-tick failed startup of other SMPS,
where
the output occurs in brief pulses at about 5 second intervals.
The load used is a #9004 halogen automotive hi/lo beam headlamp 45W 3.75A
and 65W 5.4A.

No load - the LED pulses on at about 5 second intervals, while a DMM
display
wanders erratically between 3V and 11V.

Medium load - ~45W same pulses as above, and a brighter pulse after AC
power is
shut off.

High load - ~65W same as above.

Large load - ~110W No pulses during power on or after AC is shut off.

I haven't been doing service repairs for years, but I have an isolation
transformer (PR57) and safe troubleshooting habits, but the large number
of surface mount components on the board have me leaning toward an
unlikely repair, unless someone would be willing to offer some helpful
advice.

Other observations:
As an aside comment, there is a surface mount IC where 2 of the pins have
been eliminated/omitted (not cut off), apparently to save money in
fabrication.. I've never seen this before.

The board manufacturer is Delta. For use with Information Technology
equipment.
ADP-180AB Made in China DCWP CM-2, CC: BB Rev 03.

Input: 100-240VAC 2500mA. The AC line fuse is 4A 250V.
Output: 12 VDC 15000mA.

The plastic case is unvented. The thin sheetmetal "shields" are secured to
the heatsinks with heatsink grease to increase the surface area of the
heatsinks.

--
Cheers,
WB
.............


You can do some things before giving up:
- Check the power transistor(s). If they're gone, you may find the cause of
it before replacing them and blow the new ones.
- Check the transformer for both opens and shorts. Shorts can be found by
using a ringer.
- Check secondary rectifiers and caps. A short or even a bad one can explain
your observations.
- Locate the main SMPS chip and look at its datasheet. You may find the
outlines of the circuit.
At last you can contact Delta. If they cannot help, don't want to help or
become too expensive you can always trash the thing. Delta has a reputation
in power supplies but I never need their services.

petrus bitbyter

Wild_Bill wrote:
I wasn't able to find any archived info regarding repair of this somewhat
sophisticated, high current PSU. This is the 180W version of this ADP
series
of SMPSs.

The process of disassembly wasn't trivial.. Loctite has been used on
numerous internal screws during assembly, but heating them with an iron can
loosen the threadlocker well enough to remove the screws without
stripping out the
shallow #1 phillips recesses.

The top of the single-sided 4"x6.5" board looks straighforward enough that
it appears to be repairable, however, the bottom/foil side has a lot of
surface
mount circuitry (roughly half of the bottom side) which causes me to think
that repairing these supplies isn't simple.

The in-circuit ESR of the few (only 5) electrolytics appear to be good. Two
of them are rated 125C, the others are 105C.

The single 12V output is just 2 leads to the 6-contact plug at the end of a
shielded, 12 gage cord (pins 1, 2, 3 Gnd, and 4, 5, 6 positive).

The symptom is similar to the tick-tick failed startup of other SMPS, where
the output occurs in brief pulses at about 5 second intervals.
The load used is a #9004 halogen automotive hi/lo beam headlamp 45W 3.75A
and 65W 5.4A.

No load - the LED pulses on at about 5 second intervals, while a DMM
display
wanders erratically between 3V and 11V.

Medium load - ~45W same pulses as above, and a brighter pulse after AC
power is
shut off.

High load - ~65W same as above.

Large load - ~110W No pulses during power on or after AC is shut off.

I haven't been doing service repairs for years, but I have an isolation
transformer (PR57) and safe troubleshooting habits, but the large number
of surface mount components on the board have me leaning toward an
unlikely repair, unless someone would be willing to offer some helpful
advice.

Other observations:
As an aside comment, there is a surface mount IC where 2 of the pins have
been eliminated/omitted (not cut off), apparently to save money in
fabrication.. I've never seen this before.

The board manufacturer is Delta. For use with Information Technology
equipment.
ADP-180AB Made in China DCWP CM-2, CC: BB Rev 03.

Input: 100-240VAC 2500mA. The AC line fuse is 4A 250V.
Output: 12 VDC 15000mA.

The plastic case is unvented. The thin sheetmetal "shields" are secured to
the heatsinks with heatsink grease to increase the surface area of the
heatsinks.

--
Cheers,
WB
.............


Have you measured the resistance to ground for each of the output
voltages?? You could discover why it is shutting down.

Thanks for the comments regarding various other checks.

After doing a quick check of the semis with the diode check of my BK
Precision 388-HD, and not finding any suspicious readings, I put the PSU
aside to do other stuff.

Today, with PR57 isolated supply, meter and 'scope (SC3100) arranged around
the PSU, I turned it on for testing, knowing that voltage checks might not
reveal much since the PSU is pulsing on-off.

Now the PSU is staying on with no load, or a low load of about 45W. Later,
I'll flex the board a bit and then retry startup.

BTW, I just realized I had made test connections to a live circuit, and I'm
still alive.. just not a lucky day for the alarmist types, I guess.
Also, my fingers touched lead, but it's probably too painful to amputate
them.

B+ 401VDC 0.647VAC 1.8Vp-p

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Wild_Bill" wrote in message
...
I wasn't able to find any archived info regarding repair of this somewhat
sophisticated, high current PSU. This is the 180W version of this ADP
series
of SMPSs.


--
Cheers,
WB
.............

I ended up buying 2 replacement power supplies, since this situation is a
FFAF favor for a friend, as a replacement would likely be the quickest
solution for me (I'm slow).
So I have a spare 12V 15A SMPS for other uses.
I'm reluctant to disassemble the working replacement PSUs for more testing,
since disassembly isn't as simple as opening the cases.

Luckily, both of the used replacement PSUs appear to work properly, and both
have lower ripple on their outputs (which is possibly the fault with the
original PSU).

After following up on the recommendations, and reviewing the SMPS section of
the FAQ, and determining/witnessing that the original PSU will work
intermittently, I thought I'd try my luck at getting replacements on eBay (2
units $25 each plus s/h).

http://www.repairfaq.org/sam/smpsfaq.htm#smpsmcp

The replacements have been tested with up to 8A load, so I'm somewhat
confident that they will probably be reliable.
I don't know how much current the Gateway Profile 5 all-in-one PC/laptop
needs, only that 8A is about half of the rating of the ADP-180AB PSU.

I found that a salvaged power connector/terminal strip pin header from a 286
motherboard had pins of the correct size and spacing, so a 6-pin connector
was fabricated to match the output connector of the ADP PSU.

BTW, ATX PSU power terminals aren't solid brass, the ones I examined are
precision fabricated from sheetmetal (like Molex and others).

The load used is a halogen #9004 lo/hi dual beam headlamp (45W, 65W),
mounted in
a vented aluminum can, to reduce the annoying bright light source, and as a
safety cage in the event that the pressurized lamp would burst.
Note that the cage/can gets very hot, even though it's vented with numerous
1/4" holes drilled in it, so the can/lamp socket assembly needs to be
supported in a way to prevent heat damage or ignition/fire of any nearby
objects.

The smaller 3/16" (4.76 mm) push-on quick connect crimp terminals will fit
the blade terminals in the headlamp connector socket, if closed slightly
with pliers.

The #9004 headlamp provide loads of approximately 3.4A, 4.85A and 8A

Output checks:

11.93 - 12.01VDC, lower measurement with increased load

0.103 - 0.150 VAC ripple, lower meaurement with increased load

0.290 - 0.450 Vp-p ripple, lower measurement with increased load

The original, intermittent-starting PSU checks with just the low load
(3.4A):

12.01VDC, 0.647 VAC, 1.8 Vp-p (incorrectly stated in previous post).

The AC measurements are taken with a Sencore SC3100 100MHz Auto Tracker, but
ordinary DMM measurements would likely be inaccurate, due to the frequency
of the ripple present on the DC voltage (approx 40kHz, I think).
The use of a true-RMS DMM would likely result in more accurate AC
measurements than those from a low-end DMM.


"Wild_Bill" wrote in message
...
I wasn't able to find any archived info regarding repair of this somewhat
sophisticated, high current PSU. This is the 180W version of this ADP
series
of SMPSs.

--
Cheers,
WB
.............