Sanyo DP32648 hit by lightning

[cashkennedy]

Model: Sanyo DP32648
Power Supply Model : Delta DPS-153AP-1

Picked this up on craigslist, appears the person might have checked the fuse since some screws seem missing. They said it stoped working after lightning and didnt power on. I figured it would be the fuse too since it was lightning, but i checked it and the fuse was fine. I then tested the FETs and the Bridge. There are 2 FETs both the same model number both visually look fine. 1 reads normal with all high resistances and only 2 diode readings. The other reads with a very low resistance between 1-3 and 3-1. pin 1 is the gate i believe.
1-2 --
1-3 .15 volt drop
2-1 --
2-3 .62
3-1 .15 volt drop
3-2 --

I get no power to any of the outputs 5v / 24v / 12v, (no 5v was marked as standby so i tested all outgoing wires). I probed randomly around the hot side of the board and mostly got ~ 7 volts AC.

So the part number on the FET is fischer FQP16n25c
Neither Mouser or Digikey have that instock, but mouser has FQP16n25 which has similar but slightly differnet specs. So does anyone know enough about FET specs to tell me if that will work as a replacement. (there is only 1 person on ebay with it and they are selling it as either part number not 1 specifically.)

[rayrod81]

They are the same. Mouser has them for $1.36 each,

[cashkennedy]

Sorry for slow reply, been busy at work.

I got in the replacement transistors and they didnt fix it, Thats when i realized i had been testing things to the ground screws but there was no ground wire on the plug... so i tested voltages around the primary to the neutral instead and got ~150volts though the readings jumped around (i was using DC settings since i was measuring places after the bridge).

So i realized the stadby 5v transformer was bad once i tested the board more throughly.

Its marked as
Delta MP-130I
AV-DP7018
DCWM 0814(03)2T

Ive looked around google for anything like that to order it, but cant find it. I believe its a standard stanby 5v transformer, really small one about 20mm x 25mm x 25mm. But i didnt see anything on mouser that looked to be equivalent.

So can anyone help me track down what to order to replace this transformer?

[tom66]

You need to measure the outputs relative to the COM pin on the supply output. You might get 0V.

I don't think the transformer is dead; they rarely fail.

You can check a normal SMPS transformer by testing for continuity between windings. There will probably be two windings on the primary connected to each other, and then another two separate. On the secondary there will be two or more, depending on how many outputs the standby has.

Have you tried running the supply without load? Checked the startup caps? Checked for any switching on the output at all? Checked for ~160VDC across main cap?

[cashkennedy]

I tested postive to negative on the bridge and got 168 dcv, tested positive and negative on main large cap and got 168 dvc, i tested the primary side of the transformer with the folowing pin combinations
1-5 168 vdc
1-6 168 vdc
2-5 168 vdc
2-6 168 vdc

1-2 0 vdc
5-6 0 vdc

tested the secondary and get 0 vdc (pins 7 and 8)

So i figured the primary involves a path between 1-6 and between 2-5 and that 1 and 2 are both positive and 5 and 6 are both negative. there is also a 5th pin on the primary which is in the middle and not numbered, so i would assume is just for regulation / not as important

the seconardy is pins 7 and 8 and i believe the secondary is fine

bellow are the resistance readings for various pins

1-2 1.5 ohm
1-5 --- ohm
1-6 --- ohm
2-5 --- ohm
2-6 --- ohm
5-6 0.5 ohm
7-8 0.3 ohm

so there is no connection between the first grouping (1 and 2) and the 2nd grouping (5 and 6) the extra pin on the primary seems to be the same as 5 and 6 as all 3 are continous with the negative of the bridge but 1 and 2 are not.

I believe this means the standby transformer is bad, but your welcome to comment, idk if that extra pin on the secondary is connected to an IC that can "turn off" the transformer explaining why i get voltage to the transformer just nothing out of the secondary.

[PlainBill]

Originally Posted by cashkennedy

I tested postive to negative on the bridge and got 168 dcv, tested positive and negative on main large cap and got 168 dvc, i tested the primary side of the transformer with the folowing pin combinations
1-5 168 vdc
1-6 168 vdc
2-5 168 vdc
2-6 168 vdc

1-2 0 vdc
5-6 0 vdc

tested the secondary and get 0 vdc (pins 7 and 8)

So i figured the primary involves a path between 1-6 and between 2-5 and that 1 and 2 are both positive and 5 and 6 are both negative. there is also a 5th pin on the primary which is in the middle and not numbered, so i would assume is just for regulation / not as important

the seconardy is pins 7 and 8 and i believe the secondary is fine

bellow are the resistance readings for various pins

1-2 1.5 ohm
1-5 --- ohm
1-6 --- ohm
2-5 --- ohm
2-6 --- ohm
5-6 0.5 ohm
7-8 0.3 ohm

so there is no connection between the first grouping (1 and 2) and the 2nd grouping (5 and 6) the extra pin on the primary seems to be the same as 5 and 6 as all 3 are continous with the negative of the bridge but 1 and 2 are not.

I believe this means the standby transformer is bad, but your welcome to comment, idk if that extra pin on the secondary is connected to an IC that can "turn off" the transformer explaining why i get voltage to the transformer just nothing out of the secondary.

SMPS transformers rarely fail. The usual transformer failure is a broken wire, they use a fairly heavy gauge wire even in the primary. The secondaries are wound with the equivalent of 8 or 10 gauge.

The pictures don't show enough detail to be useful. The picture of the bottom is tantalizing because it shows a couple of ICs, but not enough detail to point to a suspect.

Rather than guess, lets try a more pragmatic approach. First, I would like a picture showing the complete bottom of the power supply. Well lit, sharply focused, and at least 1000 x 1000 pixels.

Second, there are probably three ICs on the bottom of the power supply.
What are the part numbers of each?

Lastly, I would be remiss if I failed to mention that attempting to repair a TV that took a lightning hit is a real risky proposition. Normally we expect to see a single failure, sometimes a cascading failure where a shorted FET blows a fuse. After a lightning hit multiple failures are the rule rather than the exception.

PlainBill

[cashkennedy]

Well perhaps i am testing the wrong transformer, when looking at the top of the board with the primary side of the board at the bottom, and the secondary at the top, there is a big transformer on the left with 8-10 guage braided wire visible from the top (lots of thin copper 24 guage wires in each wire, not a solid core wire). Then there is a much much smaller transformer with yellow tape hiding most of the windings which are all 24 guage wire. I assumed the standby voltage was produced by the small transformer, but maybe this is a transformer for PFC ??? So would explain why im not getting an output voltage and why there are more leads connecting it to the primary side of the power supply then the secondary.

In regards to a bigger picture, I will get you one tonight, my phone doesnt do clear / large / focused picture.

The bad soldering around the FETs is from me replacing them, but i tested for diode readings from further away test points then the leads, so the connections seem to be OK. I dont believe those FETs are being used till after the power supply is told to turn on as well. I might try using a 3.3v source to start the power supply and see if it runs otherwise.

The three IC's are as follows
Larger primary IC near FETs > DEI DLA001D 90DN805
Smaler Primary IC near smaller transformer > 2A08207 5541 (no brand small circle probably from the pouring / shaping of silicon possibly peace sign)
secondary side IC > TI brand , LM258A 74M C4LNG4 (G4 is smaller and underlined)

[cashkennedy]

Looked some of those up:

The 5541 is a common 16 bit DAC i think
The TI LM258A is an op amp?

and the DEI DLA001D is available from china, but there is little else about it available online that I can find about DEI's version, im pretty sure if DEI stands for directed electronics. It appears STM and a few other people make DLA001, and I found a wierd text chat site where "Bill" says DLA0001 is actually L6598 based on information they got from badcaps.net, So i would assume thats you