Re: Can someone recommend a preheater for large boards (up to ATX size)
Thanks for the reply diif.
The Kada 853b does not seem to be most appropriate for the repairs I want to do - LGA 1700 and AM3 sockets. Looking at the LY IR6500 v2 on AliExpress tempted me buying it for myself, but not knowing if it's the right size, customs uncertainty and all the reviews about the profiles, and the thermocouple and lamp issues it was too much of a risk to take for someone with no experience.
I have about a dozen X360 boards that I wasn't able to reflow that I could use for experience....
Noo0b
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Last Activity: 12-26-2022, 06:42 PM
Joined: 05-29-2018
Location: hell
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Re: Can someone recommend a preheater for large boards (up to ATX size)
Sorry for resuscitating this thread.
I followed Learn Electronics Repair's youtube videos here and now I'm quite not encouraged to try repairing an LGA 1700 socket. I looked at the Kada 853b on Ali and really felt compelled to acquire it even if it is just for playing around with old boards.
As for the actual socket repair:
I have "no" Equipment per se but an old Madell 850b that I just brought back with epoxy and an ambiguous voltage resistance that may be somewhat iffy - with the...Leave a comment:
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Re: Element ELCHW402 won't turn on
Hi,
Thanks for the reply.
The relay clicks alright.
All voltages measured at 120VAC.
Its worth noting that everyone seems to be confused about C810.
The schematics report a 450V Cap
Every other OP with this board @ badcaps.net have a 250V 390uF cap, check my pic.
C814 was replaced along C811 and C812 before the OP.
Check the first picture on the OP and C814 is the fist to the left of the bulged blue poly cap.
C814 readings oscilate from 11.45VDC to 11.77VDC, prongs at the terminals...Leave a comment:
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Re: Element ELCHW402 won't turn on
C903 replaced.
No changes, still at 175VLeave a comment:
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Re: Element ELCHW402 won't turn on
Hi budm,
Thanks for the reply.
I checked the schematics and C810 is rated 220uF 450V indeed.
All the other OPs with this board issue report a 250V C810:
The cap measured is C9[B]0[/B]3, as CapLeaker mentioned.
My apologies for this.
Its rated 450V and reads only 175V.
If that's an indication of a defective cap, I'll try to find and replace it again.
Thanks again and kind regards.Re: Element ELCHW402 won't turn on
Hi budm,
Thanks for the reply.
I checked the schematics...Leave a comment:
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Re: Element ELCHW402 won't turn on
I'm not sure which cap I should have measured.
The biggest cap, located between the heatsinks, C810, is rated 250V and reads 221VDC.
The smaller cap located nearest from the power terminal, C913, is rated 450V and reads 175.3VDC.
Here's what they look like:...Leave a comment:
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Re: Element ELCHW402 won't turn on
I noticed that R815 is getting a bit hot and R807 is warm to the touch right after jumping STB to 5VS.
I believe those are 5.6k Ohms 5% resistors.
They are connected in series with resistance "1" if measured separately and "0" if measured at the external terminals.
Here's what they look like:...Leave a comment:
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Re: Element ELCHW402 won't turn on
Hi,
Thank you for the reply.
Good point.
Multiple rechecks indicate a consistent 3.3VDC reading.
Since no repairs were attempted since that reading, it's probably missing a paste edit.
My apologies.
Best regards and thanks one more time.Leave a comment:
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Re: Element ELCHW402 won't turn on
Hi,
Thanks for the replies.
Sorry for this, I guess I should have remembered that the main filter cap is near the power terminal. I measured C810 instead.
C913 is at 175.3VDC with the probes to the corresponding terminals on the underside of the board.
The PSU's main connector STB was jumped to 5V with a PC jumper.
Thanks again.
Best regards.Leave a comment:
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Re: Element ELCHW402 won't turn on
Hi budm,
Thank you for your reply.
I noticed the capacitor would not charge without the main bundle connected.
A computer jumper shorted STB to 5V and the voltage on the main cap was 221 VDC.
Capacitance was 0 uf. Also tried with the probes inverted on it's terminals.
The power switch did not change STB from 2.1V, and the reading on the STB leg of the 1k resistor connected to 5V was 3.3V.
I took a bunch of separate pictures of the board, that was the best I could do. I added the pictures from another OP...Leave a comment:
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Re: Element ELCHW402 won't turn on
Hi CapLeaker,
Thank you for your reply and the kit tip.
The big capacitor was at around 200 VDC right after plugging in the AC cord, then slowly discharged.
Measured with each prong at the correspondent cap terminal at the rear of the PSU.
Isn't 200 V a bit low for a 250 V capacitor?
Kind Regards and thanks again.Leave a comment:
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Element ELCHW402 won't turn on
Hello everyone.
Thanks or reading.
This TV started having trouble to power on, and after a while it just would not turn on anymore.
From my reading research, it's a common issue.
I tried every solution I found online but its still not good.
The first couple pictures are of the components I replaced.
The next two what they looked like on the board before the replacement.
The following four pictures are from the replaced components already soldered to the power board. As you can see from these pictures, some capacitors have different voltages...Last edited by Noo0b; 06-05-2018, 06:01 PM. -
Re: New Members - please post your introductions here
Hi,
I found this page looking for technical help for a TV!Leave a comment:
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