Amraks
Badcaps Veteran
Last Activity: 04-11-2025, 08:05 PM
Joined: 11-08-2011
Location: Tasmania
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No fuses blown at all.... -
This was verified under a microscope exactly what was writing on these mosfets...Leave a comment:
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Samsung One Connect SOC8002BB
HI there,
I am working on a Samsung One Connect Box Model SOC8002BB,
Fault happened in a sudden power cut.
SMPS MODEL: 65Q900B/75Q800B THL1B4401176AAM5RT1C0836
I have narrowed down a shorted Mosfet on the power board QM953CS.
Its a KEC KU 210N20P I am having no luck finding these at all replace....Last edited by Amraks; 04-10-2025, 12:55 AM. -
Sadly that secondary is gone....Leave a comment:
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Would this design be sufficient[LIST][*][B]Primary:[/B][LIST][*]230V[/LIST][*][B]Secondary:[/B][LIST][*]28VCT (14V-0V-14V) for the main rails to feed ±12V or ±15V regulators.[*]9V-0V[/LIST][*][B]Power Rating:[/B][LIST][*]40-50VA to ensure enough power for all circuits.[/LIST][/LIST]- Would this design be sufficient[LIST]
- [B]Primary:[/B][LIST]
- 230V[/LIST]
- [B]Secondary:[/B][LIST]
- 28VCT (14V-0V-14V) for the main rails to feed ±12V or ±15V regulators.
- 9V-0V[/LIST]
- [B]Power Rating:[/B][LIST]
- 40-50VA to ensure enough power for all circuits.[/LIST][/LIST]Would this design be sufficient[LIST]
- [B]Primary:[/B][LIST]
- 230V[/LIST]
- [B]Secondary:[/B][LIST]
- 28VCT
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Hey I haven't tested the transformer as I don't have a step down converter for us main to aus mains.but its got a nice burnt smell....Leave a comment:
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Roland vg-8
Anyone got any idea what voltages these transformers run this was 117v transformer plugged into Australian mains power.
2 red wires are center tapped.
I'm just trying to get a understanding of the specs I should go before getting a custom r-core built via China.
I don't really trust what is written on the transformer to what I see in the vg-88 schematic which uses the same part number.
The voltages here seem a bit low in comparison to what people have measured else where.
Filter caps are 16v
And 2 other filter caps are 25v... -
Lenovo AIO A540-24API AM4SL Rev 1.0
Looking for this schematic
Thanks in advanced who ever has uploads this. -
Re: Eeprom dump thread!
Anyone got the eeprom dump for mainboard 40-nt67ES-mac4hg?Leave a comment:
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Re: Jbl prx515
It was a dry solder Joint on the transformer, I touched up all the joints around this area including smd components.
I discovered if i pushed on u7 it would start again didn't need the freeze spray at all.
its working and not cutting out anymore.
I should of done this sooner as its been in my road for awhile now....Leave a comment:
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Re: Jbl prx515
Here is the schematic for a similar model prx518...Leave a comment:
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Re: Jbl prx515
I have found a similar schematic for a the JBL PRX 518
In the schematic RT2 is meant to be 20kohms
RT2 = 15kohms
while this is on spraying RT2 with freeze spray outputs the sound again.
Question I have is this RT2 bad?Leave a comment:
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Jbl prx515
I have a JBL speaker unit that all of a sudden is not outputting after a few minutes with sound.
This one has me baffled.
Anyone have a schematic also?
Freezing in a certain area of the board does this make this come on. not sure if this is a overheating issue or a badsolder joint or some other component. -
Re: Panasonic SA-MAX770 (not turning on)
probably a bit late of a reply but this was solved by replacing all listed chips.Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
I took them all off in order so no way of knowing if they were bad, is it possible for them Frist lines to be short to ground and be still be fine with ic4803 removed.
I think I'll replace all just to be sure than wait another two weeks for chips to get here.
Not sure what could of caused this fault.
I need to read up on the Yamaha chip
You could see some discolouration around the edge of the chip looks like it got very hot at one stage.
Excuse me if this post is not formatted...Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
Thank you RJ for getting me this far....Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
found the shorts.
So have a short on IC8005
injected some voltage to find him.
Then injected some voltage to the SW pin 10 of that IC8005 as there was a short on that line which lead me to a short IC8003 removed all these off the board.
then found the sw pin short on IC8003 so I injected voltage and found that ic4803 was getting hot.
removed IC4803 and short was gone.
Now IC4803 was not on the schematics we have here I have found that version and I will upload here with this post.
...Last edited by Amraks; 10-06-2022, 01:02 AM.Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
with everything disconnected I have measured the mainboards pcont.
it is measuring short to ground.
I have checked IC8007 pin5(en) to ground and its reading short to ground.Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
Ok there is no power on VCC of IC1501.
Confirmed using ZA1101 heatsink as the ground.
And there is no voltage on Pcont.Leave a comment:
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Re: Panasonic SA-MAX770 (not turning on)
Pin 1 has no voltage.
correct me if I am wrong but isn't PCONT just going to ground?
Also I have been using wrong ground to measure Vsen using the right ground i get 3.3v...Leave a comment:
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