Elo 1525L power board ptb-1218

[CNC_FREAK]

Re: Elo 1525L power board ptb-1218

Hello.
I have a similar problem with this board.
I have both voltages at output 5V and 15V but with a big ripple.
I measure with my osciloscope and there is a ripple of 1V with a frequency of about 3Hz, on both outputs.
Can somebody help?

[sf901]

Re: Elo 1525L power board ptb-1218

Hi, sorry to revive an old post but am also having no power on the same Elo 1525L monitor, so were you able to fix it?

[BlkSmth]

Re: Elo 1525L power board ptb-1218

swaped it from the other board... not bad. Nothing charred either, i couldnt get so lucky to see something so obvious. This thing has kicked my arse.

[PlainBill]

Re: Elo 1525L power board ptb-1218

whats the best way to test c806 with the dmm
part# is CD UF 0.01 1000V M Z5U F

If your DMM has a capacitance function, you may be able to use that. Those caps are usually a low failure rate item; when they do fail it is usually obvious by the charred remains.

PlainBill

[BlkSmth]

Re: Elo 1525L power board ptb-1218

whats the best way to test c806 with the dmm
part# is CD UF 0.01 1000V M Z5U F

[BlkSmth]

Re: Elo 1525L power board ptb-1218

Negative probe on C805 neg, Positive probe ion C807 reveals 13.2,13.4,14.1 as the chart reffers to as pulse? Urmmm... did the next step after looking up the ka3842a 8pin chip I801. I was checking pin 7 as pin 6, there is no pulse.

[Toasty]

Re: Elo 1525L power board ptb-1218

Voltage across C805? C807?

[BlkSmth]

Re: Elo 1525L power board ptb-1218

Here is a flowchart troubleshoot that might make things easier for someone to help me

still unsure where I need that black probe set for ground when checking thse values.

and then troubleshooting the d806

[BlkSmth]

Re: Elo 1525L power board ptb-1218

Here is a schematic for easy following maybe this will someone better than me. I've check every resistor now..all check good

wish I could fire this thing. Shorting Q803 was bad orginally

So far I've replaced Q803, R811, R814

any pointers other than dig a hole are welcome :P

Not sure how to test D806. I have a replacement thats exact if it was proven failed...I'd have to remove it from another board.

[BlkSmth]

Re: Elo 1525L power board ptb-1218

replaced the R811 on this thing. value checks at 1.2ohms and replaced the R814 with 47ohm 1/4w (bit larger)

still not working. any other suggestions? top portions of this board not getting power. nothing past the I802, C828

[BlkSmth]

Re: Elo 1525L power board ptb-1218

ok for replacment I have another similar board that i can rob a White, violet, silver, gold. whick calculates into .97ohm 1w for the R811. This must be better than the other suggestion of 1.8ohm 3w? any help is appreciated.

[BlkSmth]

Re: Elo 1525L power board ptb-1218

I take it that you're measuring R811 in-circuit? Since other components could be affecting your readings, you'll have to remove it from the board and retake your measurements.

maybe we have a winner on this one... its infinite all settings on DMM removed from circuit.

what are them rules for resistor replacement?

[jetadm123]

Re: Elo 1525L power board ptb-1218

I take it that you're measuring R811 in-circuit? Since other components could be affecting your readings, you'll have to remove it from the board and retake your measurements.

[BlkSmth]

Re: Elo 1525L power board ptb-1218

Start over, with the DMM on the 200 ohm scale touch the probes together what reading do you get?

Set DMM on 200, gives reading of 00.5 then goes down to 00.3 while holding for a few seconds

[alexanna]

Re: Elo 1525L power board ptb-1218

Start over, with the DMM on the 200 ohm scale touch the probes together what reading do you get?

[BlkSmth]

Re: Elo 1525L power board ptb-1218

after replacing the mosfet Q803 I've taken some time to read all resistor values per the schematics link I supplied above.

Plainbill, that R811 is a 1.2ohm 2w colors where Brown, red, gold, gold. I can get nothing but infinite on DMM set on 200,2k,20k... but when I goto 200k I get 20.0 then while holding probes I can set the DMM back to 20k and get 19.98 .....must be bad? I dont have any laying around for subs other than 1.8ohm 3w ww 5% .... not sure them rules for this. Also testing futher indicates that the R814 set DMM on 2k reads 90.7 which should be according to the colors and schematic it should be a 47ohm Yellow, violet, black, gold.

any suggestions for replacements also rules for replacing resistors with larger values? anyone anything? thanks guys! ....Blk

[BlkSmth]

Re: Elo 1525L power board ptb-1218

Got my Digikey order today

Replaced the Q803 with p4nk60zfp as a suggested relacement. still the same... pooooooop! Anyone got anymore suggestions? I'm overlooking something here. I would love to win this one. all this by shorting pins 2,3 on this Q803 originally.....

[PlainBill]

Re: Elo 1525L power board ptb-1218

Ok, I had a p4nk60zfp on another monitor. I thought the specs looks close enough to the s0220 sss4n60b. during removal with desoldering braid I think I ruined it.... The values dont seems to test on diode mode. dam it all again. Anyone got a good source so I can replace both with correct values? Also during that test plainbill had me do while in diode mode, what would the correct value or optimal would have be on the DMM?
Thanks in advance guys...........BlkSmth

the p4nk60zfp readings "Plainbill asked: Number the pins in any order and measure 1-2 1-3 2-3 2-1 3-1 3-2 (the red probe goes on the first number of each pair)" are open all except the last 3-2 which is 546 value.... They where diff before

Those numbers are NOT unreasonable for a power FET transistor. Here is the datasheet for the SSS4N60B. Note that the legs are G(ate) D(rain) S(ource) and that there is a diode which will conduct from Source to Drain (in normal operation Drain is positive with respect to Source). If you numbered in order, left to right 1=G, 2=D, 3=S, the results are exactly what I would expect.

Checking the specs, I would say the P4NK60ZPF is a good substitute for the SSS4N60B. It is available from Digi-Key for $1.40 each. Don't delay, they only have 3059 on hand.

PlainBill

[BlkSmth]

Re: Elo 1525L power board ptb-1218

cannot see giving up

I found what I think would be a good choice:# SSS4N60B s0220
http://www.mouser.com/Search/Product...y512-FQPF5N60C

Then the other I smoked... STP4NK60ZFP
http://www.mouser.com/Search/Product...11-STP4NK60ZFP

any peeps get a chance to verify that for me, that would be great. The oem datasheets are on links above........

[BlkSmth]

Re: Elo 1525L power board ptb-1218

any other takers on this mosfet swap? I dont want to destroy the board
the OEM # was 4N60B, this one is p10nk70zfp

Ok, I had a p4nk60zfp on another monitor. I thought the specs looks close enough to the s0220 sss4n60b. during removal with desoldering braid I think I ruined it.... The values dont seems to test on diode mode. dam it all again. Anyone got a good source so I can replace both with correct values? Also during that test plainbill had me do while in diode mode, what would the correct value or optimal would have be on the DMM?
Thanks in advance guys...........BlkSmth

the p4nk60zfp readings "Plainbill asked: Number the pins in any order and measure 1-2 1-3 2-3 2-1 3-1 3-2 (the red probe goes on the first number of each pair)" are open all except the last 3-2 which is 546 value.... They where diff before