Re: Funai Model LC220EM2 PS Issues
Thanks budm & Capleaker for your help and advice. I put in all the new parts today, plugged it in and the fuse did not blow. I was happy, but I waited a couple of minutes. Then I decided to get meter and start checking Voltages. That is when I smelled smoke and then the fuse F601 blew. Smoke came from L601, AC Voltage line conditioner. I touched it and it was very hot! It must be shorted on bottom side because the top and sides look new!
So maybe L601 WAS THE ORIGINAL CULPRIT all along and he wiped out everything downstream....
walldog1
Member
Last Activity: 09-03-2020, 01:39 PM
Joined: 06-19-2018
Location: Holland MI
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Re: Funai Model LC220EM2 PS Issues
I could not amend my order with Mouser this morning, but they waived the shipping on the BC33740TA. YEAH! This NPN had the highest Hfe of the 3 to pick from. I assumed it was bad as when I finally figured out C,B,E from PDF's and plugged it into my meter on Hfe setting, it read zero.
I never used this feature before but I guess it must apply some current or voltage and you would get some number on the meter. And yes, I will have to twist the leads on new Q602 as different CBE order. Thanks, and I'll let you know in a few days if...Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
You are correct. I just explained in different post what my mistake was. Thanks again. I wish I would have held off on my Mouser order until now.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
PDF shows it will work, bad link before I guess.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
I just looked at a PDF and it will work. Must of had a bad link before, sorry.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Picture showed round flat with 2 mounting holes and only 2 leads. Maybe case is 3rd lead? Current Q602 is the common usual small body (3-4mm) with three leads.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
I guess i'll buy that transistor as well. I left a reply to your previous post on suggested subs. They would require board modification. I'll get direct part # from eBay supplier. I do not want to ruin new MOSFET. And all resistors check within 5% except R602 which showed 0.8 ohms but my meter is not a fluke or any $300 or higher meter.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
BC337 would not work physically, and 2SK3561 is MOSFET and would need me to install a heatsink.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Should I remove Q602 from to test? Do you think it is necessary to test this part?Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Mouser has Q601 and I already ordered. Q602 is obsolete on Mouser, Digikey can get if I buy 50 of them. Q602 Manufacturer # is 2SC2120-Y As mentioned previously, eBay has listings for this part. It is a bipolar NPN transistor and neither C or B are shorted to E or else fuse would have blown. Am I correct? It had power to both C & B according to schematic even with Q601 out of the circuit.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Thanks for mentioning, but I double checked again just now and R610 is fine! Maybe because it measures 0.8 Ohms. Also rechecked R611 which is spot on 2.2K ohms. Somehow, all resistors survived, including the micro sized ones on other side of the board. I don't know if I could R&R R603-606 without damage to circuits as they are so small and each circuit is so close to others. But they measure right at their specified value.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Thanks CapLeaker for the light bulb in series trick. I have done that trick with automotive circuits in the past to look for circuit voltage thieves (12v bulb), but that idea never occurred to me with this project. The 2 W resistor has survived, but i'll replace all the small resistors along the path to the MOFSET and Zener D606 & D607. All other diodes test fine, but will change them as well just for age. Then everything including rectifier bridge with new 3W diodes and most of parts in HOT section will be new.
I like learning,...Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
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Re: Funai Model LC220EM2 PS Issues
I found how to test Q602 and it is bad. On Diode setting testing off board, connect + lead to D and - lead to S. It is supposed to read open (1). I get 0.001 Ohms or shorted. Found part on Mouser for $1.45 but cheapest shipping is $9.00. I want to see this work but am tired of wasting money. Plus, I still do not have R602 installed as they are discontinued.
I'll wait to hear from someone before I recycle this. It worked so GOOD until this short.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
I did not check Q601, as I was not sure how. I replaced D606, D607, D608 as all tested bad off of board. D605 & D610 tested good. The BOM of the board doe NOT show resistor R602 as Fusible resistor, nor does parts sheet. So I just bypassed it to experiment. Fuse blew instantly and so did D607 again. Looking at schematic, it has to be Q601 as shorting culprit which leads straight thru D607 to ground.
I'll check price of Q601, but I think I have spent enough money already. I am not going to check every diode on cold side...Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
Being new to this Forum, I did not get an e-mail letting me know someone had responded to my Post. How can I get notified, or is there something different I should be doing? I left the Forum open for several hours after the post and budm responded within 35 minutes, yet I never knew. I do get an email every time a new member posts. Thanks. I want to know how to help and be helped.Leave a comment:
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Re: Funai Model LC220EM2 PS Issues
To budm: Yes, I tested shorted Zener D607 off the board. I will check R610 off the board also just in case.
Regarding 3A flame proof R602, since there appears to be nothing in the aftermarket to replace it, any suggestions? Could I just put another fuse (maybe 3A?) in place of it. The 4amp fuse F601 blew and did it's job, but the short also took out R602. Seems redundant to place 2 fuses in a series circuit, 1 before rectifier, and 1 after. But I don't claim to know it all. I already ordered all the diodes, so I'll know by...Leave a comment:
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Re: ASUS 90W Charger
Personally, unless I had a spare coil, I would just replace. They don't cost much and I am sure I have the one you need if interested. Just message me if you want.Leave a comment:
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Funai Model LC220EM2 PS Issues
This unit came with my new place, left by last owner. I Plugged it in and it WORKED! Tested all inputs, outputs, ran a channel scan and had an excellent picture for it's age.
So as with all electronics, I let them run a long time as heat will eventually show any problems. 2 hours later, fuse blew. Reading other forums on similar PS's, I upgraded the rectifier diodes to the 3W as suggested. Plugged in, measured voltages, and they stopped at R602 which was open. [B]NOW 2 QUESTIONS![/B]
This 1.2 Ohm 3W [ATTACH]194116[/ATTACH]is not available anymore in any design. If... -
Re: New Members - please post your introductions here
Hello, I am a newby to this Forum. I learned and studies electronics back in the 1980's
I wrote a lengthy introduction already, but have no idea where it is at. Long story short, with my bad back, I have gotten into repairing any and all things electrical as well as mechanical.
Looking for some help, but that will be a later post.Leave a comment:
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