My first Real Post. Thanks for the Forum.
SUMMARY
======
I am presently attempting to repair a Digital Research WT322 aka DLCD32 with a Starmen Tom202cabb power supply. This power supply appears to be used in these TVs as well.
Emprex WT323
DIGITAL LIFESTYLES LT26407
DIGITAL LIFESTYLES Research WT322
SOYO MT-SYTPT2627AB
SOYO MT-SYTPT3227AB
SOYO MT-SYTPT3227AB
The main symptom is the Power LED is completely dead. Nothing happens when the power button is pressed. It is not even red in standby. It does not turn green when power button is pressed. The 5a slow blow fuse is popped. I replaced all of the caps on the power supply as there were 2 that were bulged.
As I am new to working on power supplies, I would appreciate any help steering me in the right direction to troubleshoot this power supply. Is there a way to obtain the SCHEMATIC for this item?
OBSERVATIONS
= = = = = = = = = =
1. No life whatsoever. No LED or sounds at all.
2. Fuse is blown.
3. Caps bulged -1500uf 16v C37 and 150uf 400V C09.
4. 120v measured at incoming to fuse. Other side has no reading. Removed fuse. Reads open.
5. Juncture of Q3 a [2SK3502 (N-Channel Power MosFet)],R21, RB1, D3 and D23 appears darker on the board.
TASK ACCOMPLISHED so far
= = = = = = = = = = = = = = = = =
1) Replaced all 14 capacitors.
2) After replacing capacitors and fuse, tested continuity on power supply 5 amp slow blow fuse again. It is blown. Reads Infinity.
3) Identified most of components on the board for testing or replacement.
Photos Included – If better photos needed I can dust off my Canon PowerShot Pro.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
1- Model Number Identification
2- PS Board Top View
3- PS Board Bottom View
4- PS Board Left View
5- PS Board Right View
6- Q3 suspicious area
7- Bulged Caps that led to replacing all capacitors.
8- Comparison of Large Cap replacement
Parts Identified on Board so far
===========================
BD2 – GBU606 (Bridge Rectifier)
Q1 – FQPF13N50C (N-Channel Qfet MosFet)
Q3 – 2SK3502 (N-Channel Power MosFet)
Q5 – 2SK3115 (Switching N-Channel Power MosFet)
Q11 – Unable to See because of Obstruction
D5 – MBR20150CT (Dual High Voltage Schottky Rectifier)
D6 - MBR20150CT (Dual High Voltage Schottky Rectifier)
D10 – MS865C10 (Low IR Schottky Barrier Diode)
D11 – SB2020FCT (Isolation Schottky Barrier Rectifier)
D20 - ????No Name on Part
PROBLEM
======
1) The power LED is not RED in standby mode. Press the power button and the power LED does not turn GREEN.
2) Tested continuity on power supply 5 amp slow blow fuse. It is blown. Reads Infinity.
QUESTION
= = = = = = =
1. How to obtain Schematic for the TOM202CABB? I have sent email to Starmen.com.tw to see if they can help.
2. How to Trouble Shoot power supply in general?
3. How to Trouble Shoot Tom202cabb in particular?
4. How to test un-powered board components in place if possible?
5. How to test discrete components if taken off board?
LESSONS LEARNED SO FAR
= = = = = = = = = = = = = = = = =
1. Soldering caps is MUCH easier if you tin the leads and use FLUX. Flux in solder is not enough. Only takes a second or 2 for solder to connect joint.
2. Caps are not the only item to go bad in a power supply. Quite a few people sell KITS for this Power Supply.
Thoughts on moving forward – Preliminary Plans
= = = = = = = = = = = = = = = = = = = = = = = = =
1. Test all components on the board if possible. Concentrating on Q3 and that area as a start.
Will POST results of component tests. Starting with Q3.
2. Test all components required to be removed and isolated from board.
3. Hopefully diagnosis will ID bad component.
4. If no ID. Replace all components if possible.
5. Obtain used replacement TOM202CABB as last resort.
Any help and insight would be Greatly Appreciated.
RealtyRod
SUMMARY
======
I am presently attempting to repair a Digital Research WT322 aka DLCD32 with a Starmen Tom202cabb power supply. This power supply appears to be used in these TVs as well.
Emprex WT323
DIGITAL LIFESTYLES LT26407
DIGITAL LIFESTYLES Research WT322
SOYO MT-SYTPT2627AB
SOYO MT-SYTPT3227AB
SOYO MT-SYTPT3227AB
The main symptom is the Power LED is completely dead. Nothing happens when the power button is pressed. It is not even red in standby. It does not turn green when power button is pressed. The 5a slow blow fuse is popped. I replaced all of the caps on the power supply as there were 2 that were bulged.
As I am new to working on power supplies, I would appreciate any help steering me in the right direction to troubleshoot this power supply. Is there a way to obtain the SCHEMATIC for this item?
OBSERVATIONS
= = = = = = = = = =
1. No life whatsoever. No LED or sounds at all.
2. Fuse is blown.
3. Caps bulged -1500uf 16v C37 and 150uf 400V C09.
4. 120v measured at incoming to fuse. Other side has no reading. Removed fuse. Reads open.
5. Juncture of Q3 a [2SK3502 (N-Channel Power MosFet)],R21, RB1, D3 and D23 appears darker on the board.
TASK ACCOMPLISHED so far
= = = = = = = = = = = = = = = = =
1) Replaced all 14 capacitors.
2) After replacing capacitors and fuse, tested continuity on power supply 5 amp slow blow fuse again. It is blown. Reads Infinity.
3) Identified most of components on the board for testing or replacement.
Photos Included – If better photos needed I can dust off my Canon PowerShot Pro.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
1- Model Number Identification
2- PS Board Top View
3- PS Board Bottom View
4- PS Board Left View
5- PS Board Right View
6- Q3 suspicious area
7- Bulged Caps that led to replacing all capacitors.
8- Comparison of Large Cap replacement
Parts Identified on Board so far
===========================
BD2 – GBU606 (Bridge Rectifier)
Q1 – FQPF13N50C (N-Channel Qfet MosFet)
Q3 – 2SK3502 (N-Channel Power MosFet)
Q5 – 2SK3115 (Switching N-Channel Power MosFet)
Q11 – Unable to See because of Obstruction
D5 – MBR20150CT (Dual High Voltage Schottky Rectifier)
D6 - MBR20150CT (Dual High Voltage Schottky Rectifier)
D10 – MS865C10 (Low IR Schottky Barrier Diode)
D11 – SB2020FCT (Isolation Schottky Barrier Rectifier)
D20 - ????No Name on Part
PROBLEM
======
1) The power LED is not RED in standby mode. Press the power button and the power LED does not turn GREEN.
2) Tested continuity on power supply 5 amp slow blow fuse. It is blown. Reads Infinity.
QUESTION
= = = = = = =
1. How to obtain Schematic for the TOM202CABB? I have sent email to Starmen.com.tw to see if they can help.
2. How to Trouble Shoot power supply in general?
3. How to Trouble Shoot Tom202cabb in particular?
4. How to test un-powered board components in place if possible?
5. How to test discrete components if taken off board?
LESSONS LEARNED SO FAR
= = = = = = = = = = = = = = = = =
1. Soldering caps is MUCH easier if you tin the leads and use FLUX. Flux in solder is not enough. Only takes a second or 2 for solder to connect joint.
2. Caps are not the only item to go bad in a power supply. Quite a few people sell KITS for this Power Supply.
Thoughts on moving forward – Preliminary Plans
= = = = = = = = = = = = = = = = = = = = = = = = =
1. Test all components on the board if possible. Concentrating on Q3 and that area as a start.
Will POST results of component tests. Starting with Q3.
2. Test all components required to be removed and isolated from board.
3. Hopefully diagnosis will ID bad component.
4. If no ID. Replace all components if possible.
5. Obtain used replacement TOM202CABB as last resort.
Any help and insight would be Greatly Appreciated.
RealtyRod
Attached Files
