Hi all, this one has kinda stumped me. Red light is there but power button does nothing, no clicks or picture nada. caps and diodes seem good, tested diodes, caps did a visual. only get 5vdc on the vstb pin. would this be a eprom on the main board problem?
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Re: Westinghouse VR3215
mosfets checked out fine too. think im goin to order the eprom and give that a shot -
Re: Westinghouse VR3215
ok, eprom replacement did nothingComment
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Re: Westinghouse VR3215
I only get 5volts in 5vbs. anybody got some advice? don't mind buying a board to fix, just need to know which one main or power.Comment
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Hi. I need help from wiser guys. I am amateur in electronics and can't figure this out by myself.
I bought faulty speakers, M-Audio AV40's. Other speaker has all the electronics in it and the other speaker is just passive one powered by the other speaker's amp. Original problem with the speakers was loud buzzing. I figured out that there is something wrong with the capacitors. I went ahead and replaced every electrolytic capacitor on the PCB. The caps are good quality and have the same values as the original ones.
After replacing the caps I started testing out the speaker. It seemed...09-10-2025, 10:20 AM -
Dear members,
I have a linear variable power supply with unknown brand name that I used for voltage injection.
Then it failed. I discovered that its transistors (Q1 and Q2) are shorted.
In addition, I discovered that its zener diodes are defective.
I can replace the burned transistors.
But I do not know the model of the zener diodes. the model number is not marked on the zener diodes.
Therefore, I cannot replace the zener diodes.
I do not want to test the zener diodes in a test circuit to discover their model or value.
no schematics are available... -
Hi folks. As the title says, I was doing a port replacement on a Lenovo Thinkpad T480s and in the process of post-solder cleaning, I somehow knocked off 2 or 3 diodes (i think they are diodes) near the main usb-c. I can't seem to find what kind of a diode is that. I know it's ultra tiny and just has a letter "G" on it. Would someone maybe have a proper schematic for the t480s model? I can only find the non-s one and it's quite different to the "s". Would love to figure out what component that is.
Thanks in advance!... -
- g´day! I have a samsung 22" tv monitor to fix. power supply model bn44-00505A. some stuff blown up on the primary, according to research something typical on this model. secondary seems ok. writings on the board say in outputs a5v (standby), b5v (switched) both on the lower 3 diodes on the picture, vamp and b13v (12.8v, both are the linked at the connector that goes to the main board) my question is, are both the upper diodes for 13v? I believe so but wanted to make sure before injecting voltage there to test. I injected 5v on the lower side and standby circuit is working fine
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12-18-2023, 05:45 AM - g´day! I have a samsung 22" tv monitor to fix. power supply model bn44-00505A. some stuff blown up on the primary, according to research something typical on this model. secondary seems ok. writings on the board say in outputs a5v (standby), b5v (switched) both on the lower 3 diodes on the picture, vamp and b13v (12.8v, both are the linked at the connector that goes to the main board) my question is, are both the upper diodes for 13v? I believe so but wanted to make sure before injecting voltage there to test. I injected 5v on the lower side and standby circuit is working fine
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Hey guys, i have a sony home theater power supply thats a few smd zener diodes blown but its so hard to get them. any recommendation for me to use normal zener diodes?
1. UDZSTE-1710B (9.99V 5mA) (SC-90, SOD-323F)
2. UDZSTE-1724B (24V 200mW) (SC-90, SOD-323F)
3. UDZSTE-175.1B (5.1 V 200 mW) (SC-90, SOD-323F)
These are the diodes. If i use normal zener diodes, it will work right? Question is, can i get these values on normal zener diodes?
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