AKAI MLT168A Power Supply

what is that parts number for power main board akia pdp4225m

The problem with the unit is power supply part number,MLT166A.If you can not find one you can try to fix yours.First you have to take out power supply,Replace 3 electrolytic caps EC18,EC19,EC20 all are 1000mf at 16 volt.Then find Z3 on same board,it is a 27 volt zener diode 1 watt,part number 1N4750A.Put board back in then unit should work.

the problem is in the power supply(they know about it good luck fighting them)but there is good news.you can remove the power supply and replace electrolytic caps,EC18,EC19,EC20 all of them are 1000mf at16 volt use 1000mf at25 volt.you can also go to shopjimmy.com enter model number you will see power supply part number MLT169B
it will be cheaper for you to replace the caps,the board cost about $80.00 from them

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).

EC18, EC19, EC20 are 1000uf/16v 105c
never had to replace EC9 and EC10 but should by the same value look at the size if the same as EC18 - EC20 I would go with the same value. It should be printed on the caps. If that did not fix your dead unit replace the power supply board and same time.

Check for the parts here:

http://www.mcmelectronics.com

# NOTE - If this info was helpful to anyone please click on yes!

look closely at the electrolytic capacitors in the power supply. If you see any with the tops bulging out, replace them. Especially the 1000mfd caps labeled EC9, EC10, EC18, EC19, EC20

After a little consideration...I believe this is a problem with the Main Board (Part Number: E7802-004008) Because the Pwr Led is blinking..that tells me that the problem most likely is not the pwr supply, but the Main Bd which controls the turning on of the Pwr Supply. This part on Vance Baldwin will cost you $289.69...however...the part is on factory back-order..which tells me that there must be a great deal of these boards going bad in the field..for them to have none in stock.....if you are in warrantee...scream til they give you a new one...if you r not...order the board and wait a month or so until it comes in...then replace it.........good luck and remember to get all the screws back in!
mike