Re: Insignia NS-39L700A12 backlight transformer high pitched wine
Is this V503???? Explain "dead", shorted, open, leaky ? If it is this transistor it is the vcc switch for the main and pfc ic's
Slow turn on is likely due to bad caps, C536 & C531, standby startup cap. & vcc supply cap.
C519 & C520 are vcc & start cap for the main ic N504
Have you checked the voltage across the main filter C517? check it in standby and then again when the tv is turned on. this voltage should be 160vdc in standby and go up to around (200vdc?) when tv is on.
-
Re: Insignia NS-39L700A12 backlight transformer high pitched wine
I tested this pnp transistor and it seems to be dead, could that cause my problem? It was pretty close to the big capacitor where I heated the board with a hairdryer.Attached Filesif you find these attachements useful please consider making a small donation to the site
Leave a comment:
-
-
-
Re: Insignia NS-39L700A12 backlight transformer high pitched wine
grounding screws are missingLeave a comment:
-
Re: Insignia NS-39L700A12 backlight transformer high pitched wine
Are you sure heating C517 changed the operation or were you heating one of the smaller caps like C519 C520
You should be able to try the two 270µf and see if it makes a differenceLast edited by R_J; 01-23-2021, 04:24 PM.Leave a comment:
-
-
Re: Insignia NS-39L700A12 backlight transformer high pitched wine
It's just the picture but heating the big cap made it turn on, now to find a replacement.Attached Filesif you find these attachements useful please consider making a small donation to the site
Last edited by MikeRWK; 01-23-2021, 04:17 PM.Leave a comment:
-
-
Re: Insignia NS-39L700A12 backlight transformer high pitched wine
There look like there are at least 2 bad caps, C556 & C554, (or it is just the angle of the picture) start by replacing them. One is for the standby +5 the other is for the +12v. see if that helps.Last edited by R_J; 01-23-2021, 03:55 PM.Leave a comment:
-
Insignia NS-39L700A12 backlight transformer high pitched wine
The tv won't turn on most of the time. It will try for a few seconds and quit, there's a lower buzzing then if it fires the transformer whines. All the caps look good visually there aren't any bulged caps or indications of leakage.
When I press on the transformer in question the whine changes.
Here's a video of it https://streamable.com/gatxa4Attached Filesif you find these attachements useful please consider making a small donation to the site
-
-
Hello!
I'm looking at an original Xbox PSU: Foxlink ftps-0002 rev. B. The 12 V output is too low, and the 5 V output is too (?) high. Unfortunately I don't have an oscilloscope but only a DMM for diagnosis.
Measured voltages with no load:
After rectifier diodes
12V: 6.17 V
5V: 5.67 V
Secondary transformer pins AC measurement (really don't know if this says anything)
12V: 2-2.5 V
5V: 1.04 V
I also have another (working) Xbox psu from Delta. The same measures there, in order, being: 10.79,... -
Hello Community,
I'm attempting to repair the SMPS on a Levoit 600S air purifier. The transformer is likely open. It has six pins. 2 pairs on the primary side (one pair tested open) and 1pair of legs on the secondary side. Legs on the secondary side are spread wide apart (end-to-end). I've circled them in blue. Dimentons of the transformer are 22x23mm. Marking on the transformer are EE16 1.9mH-B. Fuse for the powerboard is fuse 250V 3.15A. I've been unable to find an exact match and I'm hoping for some help here to find a suitable replacment.
Peace
LM...11-04-2025, 09:35 AM -
Issue: Funai FW55D25F - High Pitched Squeal Upon Power-on.
Solution: Replace C3208 and C3209 on main board. These are surface mounted capacitors. Values unknown so I just used same physical size capacitors from a donor board. -
Hi all,
Got this local made DC power supply (12/14V) given free as the transformer has melted. There is no marking or indication to identify what type or rating of transformer used.
Fyi,. I had a busted autogate mainboard with transformer with marking 13-0-13 . Is this the 13v dc type transformer?
My questions are
1. How do i test to see if the transformer is in good working condition?
2. Can this transformer (marking 13-0-13) be used to replace the melted transformer on the DC power supply?
Hope you guys understand what i was asking. My intention is... -
I have a blown smps and I am looking for some reassurance as to the amount of diagnosis I have to do. It blew the instant I plugged it in not under any load.
As you can see from the attached pix, the damage is located around the main or bulk capacitor (since removed for testing) and the resistor array/network that drives it (the bunch of SMD components to the left of the YAMAHA YC775 AMPS logo). The burn mark on the frame clearly shows the pins of the capacitor. And, for the avoidance of doubt, there is no way the board could have contacted the frame, it was correctly mounted on...
Leave a comment: