blackillusion
Member
Last Activity: 07-19-2022, 09:34 AM
Joined: 11-04-2010
Location:
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Yes can use it directly the ec in one chip w25x40 and the bios in the other w25q32 -
Re: LG HT33S - Loud High Pitch Tone
Well t902 has no output voltage. Ive tested components one by one and capacitors seem to be ok. Could it just be that IC902 is faulty? -
Re: LG HT33S - Loud High Pitch Tone
Ok guys, I am in the process of setting my esr meter around the board I have two ceramic caps that appear to do nothing but I'm not sure if my meter doesn't support the value?
2a272J doesn't give a reading when using esr meter just - -
Again thanks guysLeave a comment:
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Re: LG HT33S - Loud High Pitch Tone
I have taken another look into this and would assume that the 35v being 30.5v is the problem. Low voltage makes pwm squeal. ?Leave a comment:
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Re: LG HT33S - Loud High Pitch Tone
Hi budm thanks again for your help. Well if the sub speaker is plugged in to the PWM circuit the tone comes through that speaker so I would assume it goes through the rest. I can confirm tomorrow?Leave a comment:
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Re: LG HT33S - Loud High Pitch Tone
Hi budm thanks for your reply. I have just tested and only have 30.5v. All other voltages are present. Although 12v is showing 11.9v or something similar. But all are present very close to their specified
The high pitch comes directly from the PWM board, I don't have to have the speakers plugged in and its making the tone....Leave a comment:
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Re: LCD19DVDID-107-Channel stuck when left
Im looking to have another look at this soon. but if anyone had any ideas I can check. Unfortunately no schematic so its a bit blindLeave a comment:
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Re: LG HT33S - Loud High Pitch Tone
Ok so I finally got my 3.5v regulator exact match and still get the high pitch tone. It appears that I dont have the 35v on the other connector though Maybe I'm not testing correctly I think I need to check tomorrow as I only went over it quickly. Believe it stops a the switching transistor on the hot side.???
I will verify that. If a pwm is low or no voltage at a point would that cause the high pitch noiseLeave a comment:
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Re: LCD19DVDID-107-Channel stuck when left
Hi tom66, yeah ok no worries. I will have a good look over the board to see if there are any other markings. Thanks for your efforts...Leave a comment:
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Re: LCD19DVDID-107-Channel stuck when left
Hi tom66 I'm at work at the moment but if this helps it is the same one here:
[url]http://item.mobileweb.ebay.co.uk/viewitem?itemId=130658401833[/url]
If that's any use. If not let me know and I will try to get a photo asapRe: LCD19DVDID-107-Channel stuck whe... If not let me...Leave a comment:
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Re: LCD19DVDID-107-Channel stuck when left
Okay tom66
Power supply has:
ACP007-G
Mainboard has:
plv3619d-01-03
No obvious manufacturer marksLeave a comment:
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Re: LCD19DVDID-107-Channel stuck when left
Hi tom66 thanks for your response. I have just tested this to no change.
Whats strange is that the - stby, vol+, vol- and menu buttons all work when the ch+/ch- stops. On both the remote and the panel board.
Look like its going to be a long one. I'm guessing that a capacitor on the line for ch+/- is going down once its filled? sound likely?
Shame I have no schematic things are much easier then....Leave a comment:
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LCD19DVDID-107-Channel stuck when left
Hey guys I have this
Technika LCD19DVDID-107
When you start it up you can channel hop, but it does start to get sluggish.
If you leave it on a channel and come back 5 minutes later its locked on that channel and you cannot change with either the remote or panel buttons.
I opened it up, power supply seems ok although it had a bulging cap on the secondary side. I replaced that, and esr checked the cap it was faulty.
Now this problem goes away if you turn off then back on. You can turn to standby from remote or panel. -
Re: LG HT33S - Loud High Pitch Tone
looks like some idiot put a 5v regulator in instead of a 3.5v/3.3v
it has been opened before by some shop. We got it through ebay.
schematic says it should be a 278R35, but its got a 78R05 in.
I cannot source a 278R35 at the moment. Looked on farnell.
the spec sheet says its a 2a ldo 3.5v
[url]http://www.digchip.com/datasheets/parts/datasheet/598/KIA278R35PI-pdf.php[/url]
can I swap for a 1A? or would that be bad?Re: LG HT33S - Loud High Pitch Tone
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Re: New Members - please post your introductions here
Hello,
I came here because I need a hero. haha. Im from the UK, I enjoy fixing electronics and find it interesting.
Normally I'm repairing computers(software i.e windows), Laptops(broken jacks) games console and ipods etc. I learnt a great deal of info over the past couple of days from various sources when I was trying to diagnose a SMPS issue- Which then turn out fine, but now I know alot more.Leave a comment:
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LG HT33S - Loud High Pitch Tone
Hi guys,
I have an issue with this. It appears to be coming from the PWM circuit
[url]http://youtu.be/ryxeJLIIbaY[/url]
I had an inductor L606 the had come loose from the solder joints and replaced it back in circuit. I tested to see if it had shorted but it had not.
I tested the caps with ESR and they check ok.
Any ideas what could have failed. I'm leaning towards and IC
Service Manual/Schematic
PWM circuit is page 44
Please note I have a DMM and ESR tester, nothing more.
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