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Old 02-24-2019, 06:57 AM   #7
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Default Re: FeelTech / Kuman FY6600 DDS Function Arbitrary Waveform Generator repair

Originally Posted by CapLeaker View Post
Took the main board out and find a short at T2 (78L05) regulator between the input and GND pin. Took that out including the cap that is next to it and still have a short. I also measured shorts between C53 and C57. Took these out, took the 2 IC's under that heat sink out and still a short! Running out of options I decided to go old fashioned way hunting a short. Feed Power! Fed 5V 1.2A on the shorted line, doused half of the board with alcohol and success! SMD cap C81 bubbling! Replaced that with another cap the same size I found on a TV main board, put that in, soldered in all the parts I had taken out, reassembled it and I've got a working Function Generator.
This is very interesting in how you found the shorts that were on this board
This was very interesting reading I enjoyed it Thanks for sharing this
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *

These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board

All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
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