Post MAG LT782s 17" LCD Monitor

[severach]

Power Supply Inverter: 860-ALZ-M713-F AI-0088 REV: F
Inverter Section:
T101, T102: CCFL Transformer P0136 PB226
C105, C101: Samxon GK 150uf 25v ESR>20
U101, U105, U102, U104: Alpha Omega AO4606 30v 6A dual MOSFET N P
U103: Beyond Innovation BIT3193G CCFL PWM Controller

Power Supply Secondary:
D009: Unpopulated double diode in parallel with D007
D008: Korea Electronics KIA7812API 12v linear regulator
D007: MBR10100CT 100v 10A dual diode
D006: SBL1060CT 60v 10A dual diode
C020: Samxon GF 220uf 25v
C009, C010: Ceramic Cap
C011: Samxon GF 220uf 25v ESR>20
C013, C019, C027, C014: Samxon GF 1000uf 25v
C012: Samxon GF 470uf 25v
F003: MST Fuse 3.15A 250v CQ

Power Supply Primary:
Q001: Fuji 2SK2645 N Channel MOSFET
C001: Samxon KM 100uf 450v
C006: Samxon GF 47uf 25v
IC001: 203D6 PKGA SOIC-8 PWM
CY003: Everlight EL817 Photocoupler
T002: Transformer PT-003184 2650C0089 LITAI 0504

Power paths
C001:160v -> IC101+Q001 -> T002 -> D006:5v,D007:12v
D006 -> C027+C014 -> L002 -> C012 -> F003 -> 5v scaler -> ZD003 -> GND
D007 -> C013+C019 -> L001 -> C011 -> D008 7812 regulator -> C020 -> JP30 -> 12v scaler
C011 -> C101 -> JP28+JP12 -> 12v CCFL supply to U101,U105
C101 -> JP27+JP29+JP5 -> C105 12v CCFL supply to U102,U104

CN1: 1=12v, 2=12v, 3=GND, 4=GND, 5=5v, 6=5v, 7=BL, 8=GND, 9=GND, 10=N/F

Scaler: P05-00B-M713-?? illegible, 200-100-M713 REV:S3
F1: SMD Fuse
U1: Chino-Excel CEM9435A P Channel MOSFET
I3: 1084-18CE 1.8v LDO Regulator
I2: Finder Tech FS8860-33CJ 3.3v 1A LDO Regulator
U5: Macronix MXIC MX10E8050IQC 80C51 CPU with onboard FLASH
U2: Microchip 24LC21A EEPROM (printed LC21a which could be misconstrued as 74LC21A)
U4: ST Microelectronics ST24C16W6 EEPROM
U101: ST Microelectronics TDA7496L 2W+2W AMPLIFIER
U3: Mstar TSU16AK SXGA LCD Controller
TC6, TC4, TC3, TC104, TC120: YEC 220uf 16v
TC1, TC2: YEC 47uf 16v
TC102, TC101: LEAGUER RT1 220uf 16v

Panel: Proview PV170LCM-C01P M170E5-P01

Extensive heat damage around U101, U105, C101. U101 and U105 have melted their solders and discolored their copper. Heat damage around U102. U102 is burned at S2G2D2 and shorted at S1G1D1. C011 is bulged. Excessive ESR on C105, C101, C111. C101, C105 did not bulge. TC102 on the scaler is bulged.

Looks to me like the 3 12v caps leading to the inverter failed and the CCFL PWM controller didn't shut down until U102 shorted. U101 and U105 nearly desoldered themselves. The monitor still powers on for a minute from a cold start and for 5 seconds after warmed up.

I don't have an AO4606 and this would require a total recap. This stinks of bad design and at 17" is not worth fixing.

[severach]

Re: Post MAG LT782s 17" LCD Monitor

The power supply design is almost identical to the other board with a completely different look and different brand parts.

Power Supply Inverter: Mirage Electronics AD-1700 REV:F 200-000-1700B 860-AB0-1700 AD1700 J13-006D 1105C
Inverter Section:
T1, T2: CCFL Transformer 730-703-1700B EEL19-AD1700
CE1, CE2: Transformer 745-903-2064 BJ
F2: Fuse 3.15A 250v
C3, C29: Xunda XM 10uf 50v 5x7 ESR=(14.7, 17.8)
C15, C14: Xunda TL 100uf 25v WV=12v 6x7 ESR=(>20, >20)
U1, U2, U3, U4: Alpha Omega AOD444 60V N-Channel MOSFET
IC1: TI TL494C SMPS Controller

Power Supply Secondary:
IC204: ST Microelectronics L7812CV 12v linear regulator
D205A: Unpopulated double diode in parallel with D205
D205: MBR10100CT 100v 10A dual diode
D204: SBL1060CT 60v 10A dual diode
C219: Xunda TM 220uf 25v WV=12v 8x12 ESR=3.3
C223, C209, C210: Xunda TM 470uf 25v WV=13v 10x15 ESR=(>20, >20, >20)
C224, C211, C212: Xunda TM 470uf 25v WV=5v 10x15 ESR=(10.8, 3.6, 1.1)
F3: Fuse 3.15A 250v

Power Supply Primary:
F201: Fuse 3.15A 250v
Q201: Fairchild SSP7N60B 600V N-Channel MOSFET
C201: Fuhjyyu KM 100uf 400v
C203: Xunda TM 47uf 50v 6x11 ESR=1.52
IC201: 203D6 PMGD SOIC-8 PWM
IC202: 817B Photocoupler
IC203: 431 Shunt Regulator
T201: Transformer HIS-8A BIING JEY ER2819-AD1700 0508 730-102-1700A E149531

Power paths
C201:160v -> IC201+Q201 -> T201 -> D204:5v,D205:12v
D204 -> C224+C211 -> L201 -> C212 -> F3 -> 5v scaler -> Z202A -> GND
D205 -> C223+C209 -> L202 -> C210 -> IC204 7812 regulator -> C219 -> J204 -> J202 -> 12v scaler
C210 -> F2 -> JP8 -> C14 12v CCFL supply to U1,U12
F2 -> JP9 -> C15 12v CCFL supply to U3,U4

CN1 (numbering is from other board): 1=12v, 2=12v, 3=GND, 4=GND, 5=5v, 6=5v, 7=BRI, 8=GND, 9=GND, 10=BLON

Scaler: H05-00E-M713-S3, 200-100-M713 REV:S3

Panel: Proview PV170E5-C01P M170E5-P01

This one has a different brand power inverter. No sign of life. No bulged caps. The 5v side is putting out 3.16v and the 12v side is putting out 12v. The waveform on 5v looks bad. I'm too lazy to pull caps to test them so I tack on a good cap into the 5v. The power supply comes on and 5v is up to full voltage so I know the caps are bad. The in circuit ESR of the 5v supply is 1.49 ohms. ESR on pulled capacitors shows a different story. There isn't a capacitor that hasn't failed.

Working good with all new caps.

[Behemot]

Re: Post MAG LT782s 17" LCD Monitor

Got the second board in a BenQ I think. Gonna swap small caps for Nichicon VZs, acording to it still working with caps arround 3 ohms ESR in yoru case, I think it is good enough