Toshiba faults Power supply FET short circuuit and resistors R974/977 are open circuity

press the power button once it one for a couple of seconds and wait til your printer respond, once it respond it will print a list of the transaction on the printer. Hope it helps thanks.

Might be power supply board faulty, if you are tech guy open power supply board check fuse.. if its open check bridge rectified and FET. in primary section if any component short replace it...

A nice little Control IC but when they fail ithey take out a lot of components around the power supply especially the output FET rather catastrophically for the power board.
I would look elsewhere for your fault because if there is a flashing light, the microprocessor has power and that comes from the power supply.
Look for open circuit fuseable links.
Hope that helps.

Check the power supply transformer primary driver transistor and the associated components (some diodes and capacitors, resistors, an optocoupler maybe) and the rectifier diodes (or a bridge) and capacitors at the transformer secondary, what you are looking for is a short circuit, however, the short may as well be in another section of the circuit board (a shorted component may sometimes have signs of damage caused by heat, but this is not a rule).

Hope you can find out what it is...

regards

Triarcuate

I think this might be bad/swollen capacitors in your power supply, or something odd in the +5VDC circuits of the power supply, but I am posting all of the things I have found so far with these TVs.

Here are few possible solutions:
If you have no red light and you have a Megmeet MLT386 power supply, check these parts:
1) Swollen caps on the PS secondary circuit (may cause the red light blink or shutdown problems).
2) Blown fuse F1 (5A/250V) this is caused by a shorted FET at QA1 (20N60), you may also find that SMT cap CX23 is burned up (.001uf) which is in parallel with diode DA2 which may be damaged/shorted, replace these components.
If the power LED goes from red to green when powered up but no picture, then it might be lost +24VDC from the power supply:
3)Check fuse F2 (3.15A/250V, I put a 5A in), if it is blown, replace FET at QA2A (9N50C), replace QA2 as well (9N50C). Check SMT resistors at R233,R234,R235,R236 (.47 ohm). If open, replace with .1 ohm 1W or 2W resistor (easier to source). Also replace SMT transistor QF1 (2X4 or 2N4401 NPN transistor). And replace diodes at DS2 and DS1 (HER207), DS2 was shorted, DS1 was ok but I replaced it anyway.

I dont know as much about the Megmeet MLT169A, but it has similar problems and similar components.
4) I had to replace all of the capacitors in the secondary circuit (there are six in a 3x3 row marked EC9 (1000uf35V),EC10(1000uf35V),EC14(470uf35V) and EC18,EC19,EC20 (all 1000uf35V).

OK for the Megmeet MLT169A with red flashing LED when turned on we found that IC7 was bad. This is an SMT component on the solder side of the power supply. It is a 4407P (P channel 30V MOSFET). For testing purposes, we jumped across it to feed +5V to the TV permenently instead of allowing +5V to go into standby.

Does the red light come on? does it go green but no picture? Here are few possible solutions:

If you have no red light and you have a Megmeet MLT386 power supply, check these parts:

1) Swollen caps on the secondary circuit.
2) Blown fuse F1 (5A/250V) this is caused by a shorted FET at QA1 (20N60), you may also find that SMT cap CX23 is burned up (.001uf) which is in parallel with diode DA2 which may be damaged/shorted, replace these components.

If the power LED goes from red to green when powered up but no picture, then it might be lost +24VDC from the power supply:

3)Check fuse F2 (3.15A/250V, I put a 5A in), if it is blown, replace FET at QA2A (9N50C), replace QA2 as well (9N50C). Check SMT resistors at R233,R234,R235,R236 (.47 ohm). If open, replace with .1 ohm 1W or 2W resistor (easier to source). Also replace SMT transistor QF1 (2X4 or 2N4401 NPN transistor). And replace diodes at DS2 and DS1 (HER207), DS2 was shorted, DS1 was ok but I replaced it anyway.

I dont know as much about the Megmeet MLT169A, but it has similar problems and similar components.

4) I had to replace all of the capacitors in the secondary circuit (there are six in a 3x3 row marked EC9 (1000uf35V),EC10(1000uf35V),EC14(470uf35V) and EC18,EC19,EC20 (all 1000uf35V).

The following parts can be purchased at digikey.com or mouser.com web site. I am also posting all of the things I have found so far with these TVs.

Here are few possible solutions:

If you have no red light and you have a Megmeet MLT386 power supply, check these parts:

1) Swollen caps on the secondary circuit (may cause the red light blink problem, but also see below).
2) Blown fuse F1 (5A/250V) this is caused by a shorted FET at QA1 (20N60), you may also find that SMT cap CX23 is burned up (.001uf) which is in parallel with diode DA2 which may be damaged/shorted, replace these components.

If the power LED goes from red to green when powered up but no picture, then it might be lost +24VDC from the power supply:

3)Check fuse F2 (3.15A/250V, I put a 5A in), if it is blown, replace FET at QA2A (9N50C), replace QA2 as well (9N50C). Check SMT resistors at R233,R234,R235,R236 (.47 ohm). If open, replace with .1 ohm 1W or 2W resistor (easier to source). Also replace SMT transistor QF1 (2X4 or 2N4401 NPN transistor). And replace diodes at DS2 and DS1 (HER207), DS2 was shorted, DS1 was ok but I replaced it anyway.

I dont know as much about the Megmeet MLT169A, but it has similar problems and similar components.

4) I had to replace all of the capacitors in the secondary circuit (there are six in a 3x3 row marked EC9 (1000uf35V),EC10(1000uf35V),EC14(470uf35V) and EC18,EC19,EC20 (all 1000uf35V).
OK for the Megmeet MLT169A with red flashing LED when turned on I found that IC7 was bad. This is an SMT component on the solder side of the power supply. It is a 4407P (P channel 30V MOSFET). For testing purposes, we jumped across it to feed +5V to the TV permenently instead of allowing +5V to go into standby.

I think this might be bad/swollen capacitors, or something odd in the +5VDC circuits of the power supply, but I am posting all of the things I have found so far with these TVs.

Here are few possible solutions:

If you have no red light and you have a Megmeet MLT386 power supply, check these parts:

1) Swollen caps on the secondary circuit (may cause the red light blink problem).
2) Blown fuse F1 (5A/250V) this is caused by a shorted FET at QA1 (20N60), you may also find that SMT cap CX23 is burned up (.001uf) which is in parallel with diode DA2 which may be damaged/shorted, replace these components.

If the power LED goes from red to green when powered up but no picture, then it might be lost +24VDC from the power supply:

3)Check fuse F2 (3.15A/250V, I put a 5A in), if it is blown, replace FET at QA2A (9N50C), replace QA2 as well (9N50C). Check SMT resistors at R233,R234,R235,R236 (.47 ohm). If open, replace with .1 ohm 1W or 2W resistor (easier to source). Also replace SMT transistor QF1 (2X4 or 2N4401 NPN transistor). And replace diodes at DS2 and DS1 (HER207), DS2 was shorted, DS1 was ok but I replaced it anyway.

I dont know as much about the Megmeet MLT169A, but it has similar problems and similar components.

4) I had to replace all of the capacitors in the secondary circuit (there are six in a 3x3 row marked EC9 (1000uf35V),EC10(1000uf35V),EC14(470uf35V) and EC18,EC19,EC20 (all 1000uf35V).